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   1// SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
   2/*
   3 * hcd_ddma.c - DesignWare HS OTG Controller descriptor DMA routines
   4 *
   5 * Copyright (C) 2004-2013 Synopsys, Inc.
   6 */
   7
   8/*
   9 * This file contains the Descriptor DMA implementation for Host mode
  10 */
  11#include <linux/kernel.h>
  12#include <linux/module.h>
  13#include <linux/spinlock.h>
  14#include <linux/interrupt.h>
  15#include <linux/dma-mapping.h>
  16#include <linux/io.h>
  17#include <linux/slab.h>
  18#include <linux/usb.h>
  19
  20#include <linux/usb/hcd.h>
  21#include <linux/usb/ch11.h>
  22
  23#include "core.h"
  24#include "hcd.h"
  25
  26static u16 dwc2_frame_list_idx(u16 frame)
  27{
  28	return frame & (FRLISTEN_64_SIZE - 1);
  29}
  30
  31static u16 dwc2_desclist_idx_inc(u16 idx, u16 inc, u8 speed)
  32{
  33	return (idx + inc) &
  34		((speed == USB_SPEED_HIGH ? MAX_DMA_DESC_NUM_HS_ISOC :
  35		  MAX_DMA_DESC_NUM_GENERIC) - 1);
  36}
  37
  38static u16 dwc2_desclist_idx_dec(u16 idx, u16 inc, u8 speed)
  39{
  40	return (idx - inc) &
  41		((speed == USB_SPEED_HIGH ? MAX_DMA_DESC_NUM_HS_ISOC :
  42		  MAX_DMA_DESC_NUM_GENERIC) - 1);
  43}
  44
  45static u16 dwc2_max_desc_num(struct dwc2_qh *qh)
  46{
  47	return (qh->ep_type == USB_ENDPOINT_XFER_ISOC &&
  48		qh->dev_speed == USB_SPEED_HIGH) ?
  49		MAX_DMA_DESC_NUM_HS_ISOC : MAX_DMA_DESC_NUM_GENERIC;
  50}
  51
  52static u16 dwc2_frame_incr_val(struct dwc2_qh *qh)
  53{
  54	return qh->dev_speed == USB_SPEED_HIGH ?
  55	       (qh->host_interval + 8 - 1) / 8 : qh->host_interval;
  56}
  57
  58static int dwc2_desc_list_alloc(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh,
  59				gfp_t flags)
  60{
  61	struct kmem_cache *desc_cache;
  62
  63	if (qh->ep_type == USB_ENDPOINT_XFER_ISOC &&
  64	    qh->dev_speed == USB_SPEED_HIGH)
  65		desc_cache = hsotg->desc_hsisoc_cache;
  66	else
  67		desc_cache = hsotg->desc_gen_cache;
  68
  69	qh->desc_list_sz = sizeof(struct dwc2_dma_desc) *
  70						dwc2_max_desc_num(qh);
  71
  72	qh->desc_list = kmem_cache_zalloc(desc_cache, flags | GFP_DMA);
  73	if (!qh->desc_list)
  74		return -ENOMEM;
  75
  76	qh->desc_list_dma = dma_map_single(hsotg->dev, qh->desc_list,
  77					   qh->desc_list_sz,
  78					   DMA_TO_DEVICE);
  79
  80	qh->n_bytes = kcalloc(dwc2_max_desc_num(qh), sizeof(u32), flags);
  81	if (!qh->n_bytes) {
  82		dma_unmap_single(hsotg->dev, qh->desc_list_dma,
  83				 qh->desc_list_sz,
  84				 DMA_FROM_DEVICE);
  85		kmem_cache_free(desc_cache, qh->desc_list);
  86		qh->desc_list = NULL;
  87		return -ENOMEM;
  88	}
  89
  90	return 0;
  91}
  92
  93static void dwc2_desc_list_free(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh)
  94{
  95	struct kmem_cache *desc_cache;
  96
  97	if (qh->ep_type == USB_ENDPOINT_XFER_ISOC &&
  98	    qh->dev_speed == USB_SPEED_HIGH)
  99		desc_cache = hsotg->desc_hsisoc_cache;
 100	else
 101		desc_cache = hsotg->desc_gen_cache;
 102
 103	if (qh->desc_list) {
 104		dma_unmap_single(hsotg->dev, qh->desc_list_dma,
 105				 qh->desc_list_sz, DMA_FROM_DEVICE);
 106		kmem_cache_free(desc_cache, qh->desc_list);
 107		qh->desc_list = NULL;
 108	}
 109
 110	kfree(qh->n_bytes);
 111	qh->n_bytes = NULL;
 112}
 113
 114static int dwc2_frame_list_alloc(struct dwc2_hsotg *hsotg, gfp_t mem_flags)
 115{
 116	if (hsotg->frame_list)
 117		return 0;
 118
 119	hsotg->frame_list_sz = 4 * FRLISTEN_64_SIZE;
 120	hsotg->frame_list = kzalloc(hsotg->frame_list_sz, GFP_ATOMIC | GFP_DMA);
 121	if (!hsotg->frame_list)
 122		return -ENOMEM;
 123
 124	hsotg->frame_list_dma = dma_map_single(hsotg->dev, hsotg->frame_list,
 125					       hsotg->frame_list_sz,
 126					       DMA_TO_DEVICE);
 127
 128	return 0;
 129}
 130
 131static void dwc2_frame_list_free(struct dwc2_hsotg *hsotg)
 132{
 133	unsigned long flags;
 134
 135	spin_lock_irqsave(&hsotg->lock, flags);
 136
 137	if (!hsotg->frame_list) {
 138		spin_unlock_irqrestore(&hsotg->lock, flags);
 139		return;
 140	}
 141
 142	dma_unmap_single(hsotg->dev, hsotg->frame_list_dma,
 143			 hsotg->frame_list_sz, DMA_FROM_DEVICE);
 144
 145	kfree(hsotg->frame_list);
 146	hsotg->frame_list = NULL;
 147
 148	spin_unlock_irqrestore(&hsotg->lock, flags);
 149}
 150
 151static void dwc2_per_sched_enable(struct dwc2_hsotg *hsotg, u32 fr_list_en)
 152{
 153	u32 hcfg;
 154	unsigned long flags;
 155
 156	spin_lock_irqsave(&hsotg->lock, flags);
 157
 158	hcfg = dwc2_readl(hsotg, HCFG);
 159	if (hcfg & HCFG_PERSCHEDENA) {
 160		/* already enabled */
 161		spin_unlock_irqrestore(&hsotg->lock, flags);
 162		return;
 163	}
 164
 165	dwc2_writel(hsotg, hsotg->frame_list_dma, HFLBADDR);
 166
 167	hcfg &= ~HCFG_FRLISTEN_MASK;
 168	hcfg |= fr_list_en | HCFG_PERSCHEDENA;
 169	dev_vdbg(hsotg->dev, "Enabling Periodic schedule\n");
 170	dwc2_writel(hsotg, hcfg, HCFG);
 171
 172	spin_unlock_irqrestore(&hsotg->lock, flags);
 173}
 174
 175static void dwc2_per_sched_disable(struct dwc2_hsotg *hsotg)
 176{
 177	u32 hcfg;
 178	unsigned long flags;
 179
 180	spin_lock_irqsave(&hsotg->lock, flags);
 181
 182	hcfg = dwc2_readl(hsotg, HCFG);
 183	if (!(hcfg & HCFG_PERSCHEDENA)) {
 184		/* already disabled */
 185		spin_unlock_irqrestore(&hsotg->lock, flags);
 186		return;
 187	}
 188
 189	hcfg &= ~HCFG_PERSCHEDENA;
 190	dev_vdbg(hsotg->dev, "Disabling Periodic schedule\n");
 191	dwc2_writel(hsotg, hcfg, HCFG);
 192
 193	spin_unlock_irqrestore(&hsotg->lock, flags);
 194}
 195
 196/*
 197 * Activates/Deactivates FrameList entries for the channel based on endpoint
 198 * servicing period
 199 */
 200static void dwc2_update_frame_list(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh,
 201				   int enable)
 202{
 203	struct dwc2_host_chan *chan;
 204	u16 i, j, inc;
 205
 206	if (!hsotg) {
 207		pr_err("hsotg = %p\n", hsotg);
 208		return;
 209	}
 210
 211	if (!qh->channel) {
 212		dev_err(hsotg->dev, "qh->channel = %p\n", qh->channel);
 213		return;
 214	}
 215
 216	if (!hsotg->frame_list) {
 217		dev_err(hsotg->dev, "hsotg->frame_list = %p\n",
 218			hsotg->frame_list);
 219		return;
 220	}
 221
 222	chan = qh->channel;
 223	inc = dwc2_frame_incr_val(qh);
 224	if (qh->ep_type == USB_ENDPOINT_XFER_ISOC)
 225		i = dwc2_frame_list_idx(qh->next_active_frame);
 226	else
 227		i = 0;
 228
 229	j = i;
 230	do {
 231		if (enable)
 232			hsotg->frame_list[j] |= 1 << chan->hc_num;
 233		else
 234			hsotg->frame_list[j] &= ~(1 << chan->hc_num);
 235		j = (j + inc) & (FRLISTEN_64_SIZE - 1);
 236	} while (j != i);
 237
 238	/*
 239	 * Sync frame list since controller will access it if periodic
 240	 * channel is currently enabled.
 241	 */
 242	dma_sync_single_for_device(hsotg->dev,
 243				   hsotg->frame_list_dma,
 244				   hsotg->frame_list_sz,
 245				   DMA_TO_DEVICE);
 246
 247	if (!enable)
 248		return;
 249
 250	chan->schinfo = 0;
 251	if (chan->speed == USB_SPEED_HIGH && qh->host_interval) {
 252		j = 1;
 253		/* TODO - check this */
 254		inc = (8 + qh->host_interval - 1) / qh->host_interval;
 255		for (i = 0; i < inc; i++) {
 256			chan->schinfo |= j;
 257			j = j << qh->host_interval;
 258		}
 259	} else {
 260		chan->schinfo = 0xff;
 261	}
 262}
 263
 264static void dwc2_release_channel_ddma(struct dwc2_hsotg *hsotg,
 265				      struct dwc2_qh *qh)
 266{
 267	struct dwc2_host_chan *chan = qh->channel;
 268
 269	if (dwc2_qh_is_non_per(qh)) {
 270		if (hsotg->params.uframe_sched)
 271			hsotg->available_host_channels++;
 272		else
 273			hsotg->non_periodic_channels--;
 274	} else {
 275		dwc2_update_frame_list(hsotg, qh, 0);
 276		hsotg->available_host_channels++;
 277	}
 278
 279	/*
 280	 * The condition is added to prevent double cleanup try in case of
 281	 * device disconnect. See channel cleanup in dwc2_hcd_disconnect().
 282	 */
 283	if (chan->qh) {
 284		if (!list_empty(&chan->hc_list_entry))
 285			list_del(&chan->hc_list_entry);
 286		dwc2_hc_cleanup(hsotg, chan);
 287		list_add_tail(&chan->hc_list_entry, &hsotg->free_hc_list);
 288		chan->qh = NULL;
 289	}
 290
 291	qh->channel = NULL;
 292	qh->ntd = 0;
 293
 294	if (qh->desc_list)
 295		memset(qh->desc_list, 0, sizeof(struct dwc2_dma_desc) *
 296		       dwc2_max_desc_num(qh));
 297}
 298
 299/**
 300 * dwc2_hcd_qh_init_ddma() - Initializes a QH structure's Descriptor DMA
 301 * related members
 302 *
 303 * @hsotg: The HCD state structure for the DWC OTG controller
 304 * @qh:    The QH to init
 305 * @mem_flags: Indicates the type of memory allocation
 306 *
 307 * Return: 0 if successful, negative error code otherwise
 308 *
 309 * Allocates memory for the descriptor list. For the first periodic QH,
 310 * allocates memory for the FrameList and enables periodic scheduling.
 311 */
 312int dwc2_hcd_qh_init_ddma(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh,
 313			  gfp_t mem_flags)
 314{
 315	int retval;
 316
 317	if (qh->do_split) {
 318		dev_err(hsotg->dev,
 319			"SPLIT Transfers are not supported in Descriptor DMA mode.\n");
 320		retval = -EINVAL;
 321		goto err0;
 322	}
 323
 324	retval = dwc2_desc_list_alloc(hsotg, qh, mem_flags);
 325	if (retval)
 326		goto err0;
 327
 328	if (qh->ep_type == USB_ENDPOINT_XFER_ISOC ||
 329	    qh->ep_type == USB_ENDPOINT_XFER_INT) {
 330		if (!hsotg->frame_list) {
 331			retval = dwc2_frame_list_alloc(hsotg, mem_flags);
 332			if (retval)
 333				goto err1;
 334			/* Enable periodic schedule on first periodic QH */
 335			dwc2_per_sched_enable(hsotg, HCFG_FRLISTEN_64);
 336		}
 337	}
 338
 339	qh->ntd = 0;
 340	return 0;
 341
 342err1:
 343	dwc2_desc_list_free(hsotg, qh);
 344err0:
 345	return retval;
 346}
 347
 348/**
 349 * dwc2_hcd_qh_free_ddma() - Frees a QH structure's Descriptor DMA related
 350 * members
 351 *
 352 * @hsotg: The HCD state structure for the DWC OTG controller
 353 * @qh:    The QH to free
 354 *
 355 * Frees descriptor list memory associated with the QH. If QH is periodic and
 356 * the last, frees FrameList memory and disables periodic scheduling.
 357 */
 358void dwc2_hcd_qh_free_ddma(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh)
 359{
 360	unsigned long flags;
 361
 362	dwc2_desc_list_free(hsotg, qh);
 363
 364	/*
 365	 * Channel still assigned due to some reasons.
 366	 * Seen on Isoc URB dequeue. Channel halted but no subsequent
 367	 * ChHalted interrupt to release the channel. Afterwards
 368	 * when it comes here from endpoint disable routine
 369	 * channel remains assigned.
 370	 */
 371	spin_lock_irqsave(&hsotg->lock, flags);
 372	if (qh->channel)
 373		dwc2_release_channel_ddma(hsotg, qh);
 374	spin_unlock_irqrestore(&hsotg->lock, flags);
 375
 376	if ((qh->ep_type == USB_ENDPOINT_XFER_ISOC ||
 377	     qh->ep_type == USB_ENDPOINT_XFER_INT) &&
 378	    (hsotg->params.uframe_sched ||
 379	     !hsotg->periodic_channels) && hsotg->frame_list) {
 380		dwc2_per_sched_disable(hsotg);
 381		dwc2_frame_list_free(hsotg);
 382	}
 383}
 384
 385static u8 dwc2_frame_to_desc_idx(struct dwc2_qh *qh, u16 frame_idx)
 386{
 387	if (qh->dev_speed == USB_SPEED_HIGH)
 388		/* Descriptor set (8 descriptors) index which is 8-aligned */
 389		return (frame_idx & ((MAX_DMA_DESC_NUM_HS_ISOC / 8) - 1)) * 8;
 390	else
 391		return frame_idx & (MAX_DMA_DESC_NUM_GENERIC - 1);
 392}
 393
 394/*
 395 * Determine starting frame for Isochronous transfer.
 396 * Few frames skipped to prevent race condition with HC.
 397 */
 398static u16 dwc2_calc_starting_frame(struct dwc2_hsotg *hsotg,
 399				    struct dwc2_qh *qh, u16 *skip_frames)
 400{
 401	u16 frame;
 402
 403	hsotg->frame_number = dwc2_hcd_get_frame_number(hsotg);
 404
 405	/*
 406	 * next_active_frame is always frame number (not uFrame) both in FS
 407	 * and HS!
 408	 */
 409
 410	/*
 411	 * skip_frames is used to limit activated descriptors number
 412	 * to avoid the situation when HC services the last activated
 413	 * descriptor firstly.
 414	 * Example for FS:
 415	 * Current frame is 1, scheduled frame is 3. Since HC always fetches
 416	 * the descriptor corresponding to curr_frame+1, the descriptor
 417	 * corresponding to frame 2 will be fetched. If the number of
 418	 * descriptors is max=64 (or greather) the list will be fully programmed
 419	 * with Active descriptors and it is possible case (rare) that the
 420	 * latest descriptor(considering rollback) corresponding to frame 2 will
 421	 * be serviced first. HS case is more probable because, in fact, up to
 422	 * 11 uframes (16 in the code) may be skipped.
 423	 */
 424	if (qh->dev_speed == USB_SPEED_HIGH) {
 425		/*
 426		 * Consider uframe counter also, to start xfer asap. If half of
 427		 * the frame elapsed skip 2 frames otherwise just 1 frame.
 428		 * Starting descriptor index must be 8-aligned, so if the
 429		 * current frame is near to complete the next one is skipped as
 430		 * well.
 431		 */
 432		if (dwc2_micro_frame_num(hsotg->frame_number) >= 5) {
 433			*skip_frames = 2 * 8;
 434			frame = dwc2_frame_num_inc(hsotg->frame_number,
 435						   *skip_frames);
 436		} else {
 437			*skip_frames = 1 * 8;
 438			frame = dwc2_frame_num_inc(hsotg->frame_number,
 439						   *skip_frames);
 440		}
 441
 442		frame = dwc2_full_frame_num(frame);
 443	} else {
 444		/*
 445		 * Two frames are skipped for FS - the current and the next.
 446		 * But for descriptor programming, 1 frame (descriptor) is
 447		 * enough, see example above.
 448		 */
 449		*skip_frames = 1;
 450		frame = dwc2_frame_num_inc(hsotg->frame_number, 2);
 451	}
 452
 453	return frame;
 454}
 455
 456/*
 457 * Calculate initial descriptor index for isochronous transfer based on
 458 * scheduled frame
 459 */
 460static u16 dwc2_recalc_initial_desc_idx(struct dwc2_hsotg *hsotg,
 461					struct dwc2_qh *qh)
 462{
 463	u16 frame, fr_idx, fr_idx_tmp, skip_frames;
 464
 465	/*
 466	 * With current ISOC processing algorithm the channel is being released
 467	 * when no more QTDs in the list (qh->ntd == 0). Thus this function is
 468	 * called only when qh->ntd == 0 and qh->channel == 0.
 469	 *
 470	 * So qh->channel != NULL branch is not used and just not removed from
 471	 * the source file. It is required for another possible approach which
 472	 * is, do not disable and release the channel when ISOC session
 473	 * completed, just move QH to inactive schedule until new QTD arrives.
 474	 * On new QTD, the QH moved back to 'ready' schedule, starting frame and
 475	 * therefore starting desc_index are recalculated. In this case channel
 476	 * is released only on ep_disable.
 477	 */
 478
 479	/*
 480	 * Calculate starting descriptor index. For INTERRUPT endpoint it is
 481	 * always 0.
 482	 */
 483	if (qh->channel) {
 484		frame = dwc2_calc_starting_frame(hsotg, qh, &skip_frames);
 485		/*
 486		 * Calculate initial descriptor index based on FrameList current
 487		 * bitmap and servicing period
 488		 */
 489		fr_idx_tmp = dwc2_frame_list_idx(frame);
 490		fr_idx = (FRLISTEN_64_SIZE +
 491			  dwc2_frame_list_idx(qh->next_active_frame) -
 492			  fr_idx_tmp) % dwc2_frame_incr_val(qh);
 493		fr_idx = (fr_idx + fr_idx_tmp) % FRLISTEN_64_SIZE;
 494	} else {
 495		qh->next_active_frame = dwc2_calc_starting_frame(hsotg, qh,
 496							   &skip_frames);
 497		fr_idx = dwc2_frame_list_idx(qh->next_active_frame);
 498	}
 499
 500	qh->td_first = qh->td_last = dwc2_frame_to_desc_idx(qh, fr_idx);
 501
 502	return skip_frames;
 503}
 504
 505#define ISOC_URB_GIVEBACK_ASAP
 506
 507#define MAX_ISOC_XFER_SIZE_FS	1023
 508#define MAX_ISOC_XFER_SIZE_HS	3072
 509#define DESCNUM_THRESHOLD	4
 510
 511static void dwc2_fill_host_isoc_dma_desc(struct dwc2_hsotg *hsotg,
 512					 struct dwc2_qtd *qtd,
 513					 struct dwc2_qh *qh, u32 max_xfer_size,
 514					 u16 idx)
 515{
 516	struct dwc2_dma_desc *dma_desc = &qh->desc_list[idx];
 517	struct dwc2_hcd_iso_packet_desc *frame_desc;
 518
 519	memset(dma_desc, 0, sizeof(*dma_desc));
 520	frame_desc = &qtd->urb->iso_descs[qtd->isoc_frame_index_last];
 521
 522	if (frame_desc->length > max_xfer_size)
 523		qh->n_bytes[idx] = max_xfer_size;
 524	else
 525		qh->n_bytes[idx] = frame_desc->length;
 526
 527	dma_desc->buf = (u32)(qtd->urb->dma + frame_desc->offset);
 528	dma_desc->status = qh->n_bytes[idx] << HOST_DMA_ISOC_NBYTES_SHIFT &
 529			   HOST_DMA_ISOC_NBYTES_MASK;
 530
 531	/* Set active bit */
 532	dma_desc->status |= HOST_DMA_A;
 533
 534	qh->ntd++;
 535	qtd->isoc_frame_index_last++;
 536
 537#ifdef ISOC_URB_GIVEBACK_ASAP
 538	/* Set IOC for each descriptor corresponding to last frame of URB */
 539	if (qtd->isoc_frame_index_last == qtd->urb->packet_count)
 540		dma_desc->status |= HOST_DMA_IOC;
 541#endif
 542
 543	dma_sync_single_for_device(hsotg->dev,
 544				   qh->desc_list_dma +
 545			(idx * sizeof(struct dwc2_dma_desc)),
 546			sizeof(struct dwc2_dma_desc),
 547			DMA_TO_DEVICE);
 548}
 549
 550static void dwc2_init_isoc_dma_desc(struct dwc2_hsotg *hsotg,
 551				    struct dwc2_qh *qh, u16 skip_frames)
 552{
 553	struct dwc2_qtd *qtd;
 554	u32 max_xfer_size;
 555	u16 idx, inc, n_desc = 0, ntd_max = 0;
 556	u16 cur_idx;
 557	u16 next_idx;
 558
 559	idx = qh->td_last;
 560	inc = qh->host_interval;
 561	hsotg->frame_number = dwc2_hcd_get_frame_number(hsotg);
 562	cur_idx = dwc2_frame_list_idx(hsotg->frame_number);
 563	next_idx = dwc2_desclist_idx_inc(qh->td_last, inc, qh->dev_speed);
 564
 565	/*
 566	 * Ensure current frame number didn't overstep last scheduled
 567	 * descriptor. If it happens, the only way to recover is to move
 568	 * qh->td_last to current frame number + 1.
 569	 * So that next isoc descriptor will be scheduled on frame number + 1
 570	 * and not on a past frame.
 571	 */
 572	if (dwc2_frame_idx_num_gt(cur_idx, next_idx) || (cur_idx == next_idx)) {
 573		if (inc < 32) {
 574			dev_vdbg(hsotg->dev,
 575				 "current frame number overstep last descriptor\n");
 576			qh->td_last = dwc2_desclist_idx_inc(cur_idx, inc,
 577							    qh->dev_speed);
 578			idx = qh->td_last;
 579		}
 580	}
 581
 582	if (qh->host_interval) {
 583		ntd_max = (dwc2_max_desc_num(qh) + qh->host_interval - 1) /
 584				qh->host_interval;
 585		if (skip_frames && !qh->channel)
 586			ntd_max -= skip_frames / qh->host_interval;
 587	}
 588
 589	max_xfer_size = qh->dev_speed == USB_SPEED_HIGH ?
 590			MAX_ISOC_XFER_SIZE_HS : MAX_ISOC_XFER_SIZE_FS;
 591
 592	list_for_each_entry(qtd, &qh->qtd_list, qtd_list_entry) {
 593		if (qtd->in_process &&
 594		    qtd->isoc_frame_index_last ==
 595		    qtd->urb->packet_count)
 596			continue;
 597
 598		qtd->isoc_td_first = idx;
 599		while (qh->ntd < ntd_max && qtd->isoc_frame_index_last <
 600						qtd->urb->packet_count) {
 601			dwc2_fill_host_isoc_dma_desc(hsotg, qtd, qh,
 602						     max_xfer_size, idx);
 603			idx = dwc2_desclist_idx_inc(idx, inc, qh->dev_speed);
 604			n_desc++;
 605		}
 606		qtd->isoc_td_last = idx;
 607		qtd->in_process = 1;
 608	}
 609
 610	qh->td_last = idx;
 611
 612#ifdef ISOC_URB_GIVEBACK_ASAP
 613	/* Set IOC for last descriptor if descriptor list is full */
 614	if (qh->ntd == ntd_max) {
 615		idx = dwc2_desclist_idx_dec(qh->td_last, inc, qh->dev_speed);
 616		qh->desc_list[idx].status |= HOST_DMA_IOC;
 617		dma_sync_single_for_device(hsotg->dev,
 618					   qh->desc_list_dma + (idx *
 619					   sizeof(struct dwc2_dma_desc)),
 620					   sizeof(struct dwc2_dma_desc),
 621					   DMA_TO_DEVICE);
 622	}
 623#else
 624	/*
 625	 * Set IOC bit only for one descriptor. Always try to be ahead of HW
 626	 * processing, i.e. on IOC generation driver activates next descriptor
 627	 * but core continues to process descriptors following the one with IOC
 628	 * set.
 629	 */
 630
 631	if (n_desc > DESCNUM_THRESHOLD)
 632		/*
 633		 * Move IOC "up". Required even if there is only one QTD
 634		 * in the list, because QTDs might continue to be queued,
 635		 * but during the activation it was only one queued.
 636		 * Actually more than one QTD might be in the list if this
 637		 * function called from XferCompletion - QTDs was queued during
 638		 * HW processing of the previous descriptor chunk.
 639		 */
 640		idx = dwc2_desclist_idx_dec(idx, inc * ((qh->ntd + 1) / 2),
 641					    qh->dev_speed);
 642	else
 643		/*
 644		 * Set the IOC for the latest descriptor if either number of
 645		 * descriptors is not greater than threshold or no more new
 646		 * descriptors activated
 647		 */
 648		idx = dwc2_desclist_idx_dec(qh->td_last, inc, qh->dev_speed);
 649
 650	qh->desc_list[idx].status |= HOST_DMA_IOC;
 651	dma_sync_single_for_device(hsotg->dev,
 652				   qh->desc_list_dma +
 653				   (idx * sizeof(struct dwc2_dma_desc)),
 654				   sizeof(struct dwc2_dma_desc),
 655				   DMA_TO_DEVICE);
 656#endif
 657}
 658
 659static void dwc2_fill_host_dma_desc(struct dwc2_hsotg *hsotg,
 660				    struct dwc2_host_chan *chan,
 661				    struct dwc2_qtd *qtd, struct dwc2_qh *qh,
 662				    int n_desc)
 663{
 664	struct dwc2_dma_desc *dma_desc = &qh->desc_list[n_desc];
 665	int len = chan->xfer_len;
 666
 667	if (len > HOST_DMA_NBYTES_LIMIT - (chan->max_packet - 1))
 668		len = HOST_DMA_NBYTES_LIMIT - (chan->max_packet - 1);
 669
 670	if (chan->ep_is_in) {
 671		int num_packets;
 672
 673		if (len > 0 && chan->max_packet)
 674			num_packets = (len + chan->max_packet - 1)
 675					/ chan->max_packet;
 676		else
 677			/* Need 1 packet for transfer length of 0 */
 678			num_packets = 1;
 679
 680		/* Always program an integral # of packets for IN transfers */
 681		len = num_packets * chan->max_packet;
 682	}
 683
 684	dma_desc->status = len << HOST_DMA_NBYTES_SHIFT & HOST_DMA_NBYTES_MASK;
 685	qh->n_bytes[n_desc] = len;
 686
 687	if (qh->ep_type == USB_ENDPOINT_XFER_CONTROL &&
 688	    qtd->control_phase == DWC2_CONTROL_SETUP)
 689		dma_desc->status |= HOST_DMA_SUP;
 690
 691	dma_desc->buf = (u32)chan->xfer_dma;
 692
 693	dma_sync_single_for_device(hsotg->dev,
 694				   qh->desc_list_dma +
 695				   (n_desc * sizeof(struct dwc2_dma_desc)),
 696				   sizeof(struct dwc2_dma_desc),
 697				   DMA_TO_DEVICE);
 698
 699	/*
 700	 * Last (or only) descriptor of IN transfer with actual size less
 701	 * than MaxPacket
 702	 */
 703	if (len > chan->xfer_len) {
 704		chan->xfer_len = 0;
 705	} else {
 706		chan->xfer_dma += len;
 707		chan->xfer_len -= len;
 708	}
 709}
 710
 711static void dwc2_init_non_isoc_dma_desc(struct dwc2_hsotg *hsotg,
 712					struct dwc2_qh *qh)
 713{
 714	struct dwc2_qtd *qtd;
 715	struct dwc2_host_chan *chan = qh->channel;
 716	int n_desc = 0;
 717
 718	dev_vdbg(hsotg->dev, "%s(): qh=%p dma=%08lx len=%d\n", __func__, qh,
 719		 (unsigned long)chan->xfer_dma, chan->xfer_len);
 720
 721	/*
 722	 * Start with chan->xfer_dma initialized in assign_and_init_hc(), then
 723	 * if SG transfer consists of multiple URBs, this pointer is re-assigned
 724	 * to the buffer of the currently processed QTD. For non-SG request
 725	 * there is always one QTD active.
 726	 */
 727
 728	list_for_each_entry(qtd, &qh->qtd_list, qtd_list_entry) {
 729		dev_vdbg(hsotg->dev, "qtd=%p\n", qtd);
 730
 731		if (n_desc) {
 732			/* SG request - more than 1 QTD */
 733			chan->xfer_dma = qtd->urb->dma +
 734					qtd->urb->actual_length;
 735			chan->xfer_len = qtd->urb->length -
 736					qtd->urb->actual_length;
 737			dev_vdbg(hsotg->dev, "buf=%08lx len=%d\n",
 738				 (unsigned long)chan->xfer_dma, chan->xfer_len);
 739		}
 740
 741		qtd->n_desc = 0;
 742		do {
 743			if (n_desc > 1) {
 744				qh->desc_list[n_desc - 1].status |= HOST_DMA_A;
 745				dev_vdbg(hsotg->dev,
 746					 "set A bit in desc %d (%p)\n",
 747					 n_desc - 1,
 748					 &qh->desc_list[n_desc - 1]);
 749				dma_sync_single_for_device(hsotg->dev,
 750							   qh->desc_list_dma +
 751					((n_desc - 1) *
 752					sizeof(struct dwc2_dma_desc)),
 753					sizeof(struct dwc2_dma_desc),
 754					DMA_TO_DEVICE);
 755			}
 756			dwc2_fill_host_dma_desc(hsotg, chan, qtd, qh, n_desc);
 757			dev_vdbg(hsotg->dev,
 758				 "desc %d (%p) buf=%08x status=%08x\n",
 759				 n_desc, &qh->desc_list[n_desc],
 760				 qh->desc_list[n_desc].buf,
 761				 qh->desc_list[n_desc].status);
 762			qtd->n_desc++;
 763			n_desc++;
 764		} while (chan->xfer_len > 0 &&
 765			 n_desc != MAX_DMA_DESC_NUM_GENERIC);
 766
 767		dev_vdbg(hsotg->dev, "n_desc=%d\n", n_desc);
 768		qtd->in_process = 1;
 769		if (qh->ep_type == USB_ENDPOINT_XFER_CONTROL)
 770			break;
 771		if (n_desc == MAX_DMA_DESC_NUM_GENERIC)
 772			break;
 773	}
 774
 775	if (n_desc) {
 776		qh->desc_list[n_desc - 1].status |=
 777				HOST_DMA_IOC | HOST_DMA_EOL | HOST_DMA_A;
 778		dev_vdbg(hsotg->dev, "set IOC/EOL/A bits in desc %d (%p)\n",
 779			 n_desc - 1, &qh->desc_list[n_desc - 1]);
 780		dma_sync_single_for_device(hsotg->dev,
 781					   qh->desc_list_dma + (n_desc - 1) *
 782					   sizeof(struct dwc2_dma_desc),
 783					   sizeof(struct dwc2_dma_desc),
 784					   DMA_TO_DEVICE);
 785		if (n_desc > 1) {
 786			qh->desc_list[0].status |= HOST_DMA_A;
 787			dev_vdbg(hsotg->dev, "set A bit in desc 0 (%p)\n",
 788				 &qh->desc_list[0]);
 789			dma_sync_single_for_device(hsotg->dev,
 790						   qh->desc_list_dma,
 791					sizeof(struct dwc2_dma_desc),
 792					DMA_TO_DEVICE);
 793		}
 794		chan->ntd = n_desc;
 795	}
 796}
 797
 798/**
 799 * dwc2_hcd_start_xfer_ddma() - Starts a transfer in Descriptor DMA mode
 800 *
 801 * @hsotg: The HCD state structure for the DWC OTG controller
 802 * @qh:    The QH to init
 803 *
 804 * Return: 0 if successful, negative error code otherwise
 805 *
 806 * For Control and Bulk endpoints, initializes descriptor list and starts the
 807 * transfer. For Interrupt and Isochronous endpoints, initializes descriptor
 808 * list then updates FrameList, marking appropriate entries as active.
 809 *
 810 * For Isochronous endpoints the starting descriptor index is calculated based
 811 * on the scheduled frame, but only on the first transfer descriptor within a
 812 * session. Then the transfer is started via enabling the channel.
 813 *
 814 * For Isochronous endpoints the channel is not halted on XferComplete
 815 * interrupt so remains assigned to the endpoint(QH) until session is done.
 816 */
 817void dwc2_hcd_start_xfer_ddma(struct dwc2_hsotg *hsotg, struct dwc2_qh *qh)
 818{
 819	/* Channel is already assigned */
 820	struct dwc2_host_chan *chan = qh->channel;
 821	u16 skip_frames = 0;
 822
 823	switch (chan->ep_type) {
 824	case USB_ENDPOINT_XFER_CONTROL:
 825	case USB_ENDPOINT_XFER_BULK:
 826		dwc2_init_non_isoc_dma_desc(hsotg, qh);
 827		dwc2_hc_start_transfer_ddma(hsotg, chan);
 828		break;
 829	case USB_ENDPOINT_XFER_INT:
 830		dwc2_init_non_isoc_dma_desc(hsotg, qh);
 831		dwc2_update_frame_list(hsotg, qh, 1);
 832		dwc2_hc_start_transfer_ddma(hsotg, chan);
 833		break;
 834	case USB_ENDPOINT_XFER_ISOC:
 835		if (!qh->ntd)
 836			skip_frames = dwc2_recalc_initial_desc_idx(hsotg, qh);
 837		dwc2_init_isoc_dma_desc(hsotg, qh, skip_frames);
 838
 839		if (!chan->xfer_started) {
 840			dwc2_update_frame_list(hsotg, qh, 1);
 841
 842			/*
 843			 * Always set to max, instead of actual size. Otherwise
 844			 * ntd will be changed with channel being enabled. Not
 845			 * recommended.
 846			 */
 847			chan->ntd = dwc2_max_desc_num(qh);
 848
 849			/* Enable channel only once for ISOC */
 850			dwc2_hc_start_transfer_ddma(hsotg, chan);
 851		}
 852
 853		break;
 854	default:
 855		break;
 856	}
 857}
 858
 859#define DWC2_CMPL_DONE		1
 860#define DWC2_CMPL_STOP		2
 861
 862static int dwc2_cmpl_host_isoc_dma_desc(struct dwc2_hsotg *hsotg,
 863					struct dwc2_host_chan *chan,
 864					struct dwc2_qtd *qtd,
 865					struct dwc2_qh *qh, u16 idx)
 866{
 867	struct dwc2_dma_desc *dma_desc;
 868	struct dwc2_hcd_iso_packet_desc *frame_desc;
 869	u16 remain = 0;
 870	int rc = 0;
 871
 872	if (!qtd->urb)
 873		return -EINVAL;
 874
 875	dma_sync_single_for_cpu(hsotg->dev, qh->desc_list_dma + (idx *
 876				sizeof(struct dwc2_dma_desc)),
 877				sizeof(struct dwc2_dma_desc),
 878				DMA_FROM_DEVICE);
 879
 880	dma_desc = &qh->desc_list[idx];
 881
 882	frame_desc = &qtd->urb->iso_descs[qtd->isoc_frame_index_last];
 883	dma_desc->buf = (u32)(qtd->urb->dma + frame_desc->offset);
 884	if (chan->ep_is_in)
 885		remain = (dma_desc->status & HOST_DMA_ISOC_NBYTES_MASK) >>
 886			 HOST_DMA_ISOC_NBYTES_SHIFT;
 887
 888	if ((dma_desc->status & HOST_DMA_STS_MASK) == HOST_DMA_STS_PKTERR) {
 889		/*
 890		 * XactError, or unable to complete all the transactions
 891		 * in the scheduled micro-frame/frame, both indicated by
 892		 * HOST_DMA_STS_PKTERR
 893		 */
 894		qtd->urb->error_count++;
 895		frame_desc->actual_length = qh->n_bytes[idx] - remain;
 896		frame_desc->status = -EPROTO;
 897	} else {
 898		/* Success */
 899		frame_desc->actual_length = qh->n_bytes[idx] - remain;
 900		frame_desc->status = 0;
 901	}
 902
 903	if (++qtd->isoc_frame_index == qtd->urb->packet_count) {
 904		/*
 905		 * urb->status is not used for isoc transfers here. The
 906		 * individual frame_desc status are used instead.
 907		 */
 908		dwc2_host_complete(hsotg, qtd, 0);
 909		dwc2_hcd_qtd_unlink_and_free(hsotg, qtd, qh);
 910
 911		/*
 912		 * This check is necessary because urb_dequeue can be called
 913		 * from urb complete callback (sound driver for example). All
 914		 * pending URBs are dequeued there, so no need for further
 915		 * processing.
 916		 */
 917		if (chan->halt_status == DWC2_HC_XFER_URB_DEQUEUE)
 918			return -1;
 919		rc = DWC2_CMPL_DONE;
 920	}
 921
 922	qh->ntd--;
 923
 924	/* Stop if IOC requested descriptor reached */
 925	if (dma_desc->status & HOST_DMA_IOC)
 926		rc = DWC2_CMPL_STOP;
 927
 928	return rc;
 929}
 930
 931static void dwc2_complete_isoc_xfer_ddma(struct dwc2_hsotg *hsotg,
 932					 struct dwc2_host_chan *chan,
 933					 enum dwc2_halt_status halt_status)
 934{
 935	struct dwc2_hcd_iso_packet_desc *frame_desc;
 936	struct dwc2_qtd *qtd, *qtd_tmp;
 937	struct dwc2_qh *qh;
 938	u16 idx;
 939	int rc;
 940
 941	qh = chan->qh;
 942	idx = qh->td_first;
 943
 944	if (chan->halt_status == DWC2_HC_XFER_URB_DEQUEUE) {
 945		list_for_each_entry(qtd, &qh->qtd_list, qtd_list_entry)
 946			qtd->in_process = 0;
 947		return;
 948	}
 949
 950	if (halt_status == DWC2_HC_XFER_AHB_ERR ||
 951	    halt_status == DWC2_HC_XFER_BABBLE_ERR) {
 952		/*
 953		 * Channel is halted in these error cases, considered as serious
 954		 * issues.
 955		 * Complete all URBs marking all frames as failed, irrespective
 956		 * whether some of the descriptors (frames) succeeded or not.
 957		 * Pass error code to completion routine as well, to update
 958		 * urb->status, some of class drivers might use it to stop
 959		 * queing transfer requests.
 960		 */
 961		int err = halt_status == DWC2_HC_XFER_AHB_ERR ?
 962			  -EIO : -EOVERFLOW;
 963
 964		list_for_each_entry_safe(qtd, qtd_tmp, &qh->qtd_list,
 965					 qtd_list_entry) {
 966			if (qtd->urb) {
 967				for (idx = 0; idx < qtd->urb->packet_count;
 968				     idx++) {
 969					frame_desc = &qtd->urb->iso_descs[idx];
 970					frame_desc->status = err;
 971				}
 972
 973				dwc2_host_complete(hsotg, qtd, err);
 974			}
 975
 976			dwc2_hcd_qtd_unlink_and_free(hsotg, qtd, qh);
 977		}
 978
 979		return;
 980	}
 981
 982	list_for_each_entry_safe(qtd, qtd_tmp, &qh->qtd_list, qtd_list_entry) {
 983		if (!qtd->in_process)
 984			break;
 985
 986		/*
 987		 * Ensure idx corresponds to descriptor where first urb of this
 988		 * qtd was added. In fact, during isoc desc init, dwc2 may skip
 989		 * an index if current frame number is already over this index.
 990		 */
 991		if (idx != qtd->isoc_td_first) {
 992			dev_vdbg(hsotg->dev,
 993				 "try to complete %d instead of %d\n",
 994				 idx, qtd->isoc_td_first);
 995			idx = qtd->isoc_td_first;
 996		}
 997
 998		do {
 999			struct dwc2_qtd *qtd_next;
1000			u16 cur_idx;
1001
1002			rc = dwc2_cmpl_host_isoc_dma_desc(hsotg, chan, qtd, qh,
1003							  idx);
1004			if (rc < 0)
1005				return;
1006			idx = dwc2_desclist_idx_inc(idx, qh->host_interval,
1007						    chan->speed);
1008			if (!rc)
1009				continue;
1010
1011			if (rc == DWC2_CMPL_DONE)
1012				break;
1013
1014			/* rc == DWC2_CMPL_STOP */
1015
1016			if (qh->host_interval >= 32)
1017				goto stop_scan;
1018
1019			qh->td_first = idx;
1020			cur_idx = dwc2_frame_list_idx(hsotg->frame_number);
1021			qtd_next = list_first_entry(&qh->qtd_list,
1022						    struct dwc2_qtd,
1023						    qtd_list_entry);
1024			if (dwc2_frame_idx_num_gt(cur_idx,
1025						  qtd_next->isoc_td_last))
1026				break;
1027
1028			goto stop_scan;
1029
1030		} while (idx != qh->td_first);
1031	}
1032
1033stop_scan:
1034	qh->td_first = idx;
1035}
1036
1037static int dwc2_update_non_isoc_urb_state_ddma(struct dwc2_hsotg *hsotg,
1038					       struct dwc2_host_chan *chan,
1039					struct dwc2_qtd *qtd,
1040					struct dwc2_dma_desc *dma_desc,
1041					enum dwc2_halt_status halt_status,
1042					u32 n_bytes, int *xfer_done)
1043{
1044	struct dwc2_hcd_urb *urb = qtd->urb;
1045	u16 remain = 0;
1046
1047	if (chan->ep_is_in)
1048		remain = (dma_desc->status & HOST_DMA_NBYTES_MASK) >>
1049			 HOST_DMA_NBYTES_SHIFT;
1050
1051	dev_vdbg(hsotg->dev, "remain=%d dwc2_urb=%p\n", remain, urb);
1052
1053	if (halt_status == DWC2_HC_XFER_AHB_ERR) {
1054		dev_err(hsotg->dev, "EIO\n");
1055		urb->status = -EIO;
1056		return 1;
1057	}
1058
1059	if ((dma_desc->status & HOST_DMA_STS_MASK) == HOST_DMA_STS_PKTERR) {
1060		switch (halt_status) {
1061		case DWC2_HC_XFER_STALL:
1062			dev_vdbg(hsotg->dev, "Stall\n");
1063			urb->status = -EPIPE;
1064			break;
1065		case DWC2_HC_XFER_BABBLE_ERR:
1066			dev_err(hsotg->dev, "Babble\n");
1067			urb->status = -EOVERFLOW;
1068			break;
1069		case DWC2_HC_XFER_XACT_ERR:
1070			dev_err(hsotg->dev, "XactErr\n");
1071			urb->status = -EPROTO;
1072			break;
1073		default:
1074			dev_err(hsotg->dev,
1075				"%s: Unhandled descriptor error status (%d)\n",
1076				__func__, halt_status);
1077			break;
1078		}
1079		return 1;
1080	}
1081
1082	if (dma_desc->status & HOST_DMA_A) {
1083		dev_vdbg(hsotg->dev,
1084			 "Active descriptor encountered on channel %d\n",
1085			 chan->hc_num);
1086		return 0;
1087	}
1088
1089	if (chan->ep_type == USB_ENDPOINT_XFER_CONTROL) {
1090		if (qtd->control_phase == DWC2_CONTROL_DATA) {
1091			urb->actual_length += n_bytes - remain;
1092			if (remain || urb->actual_length >= urb->length) {
1093				/*
1094				 * For Control Data stage do not set urb->status
1095				 * to 0, to prevent URB callback. Set it when
1096				 * Status phase is done. See below.
1097				 */
1098				*xfer_done = 1;
1099			}
1100		} else if (qtd->control_phase == DWC2_CONTROL_STATUS) {
1101			urb->status = 0;
1102			*xfer_done = 1;
1103		}
1104		/* No handling for SETUP stage */
1105	} else {
1106		/* BULK and INTR */
1107		urb->actual_length += n_bytes - remain;
1108		dev_vdbg(hsotg->dev, "length=%d actual=%d\n", urb->length,
1109			 urb->actual_length);
1110		if (remain || urb->actual_length >= urb->length) {
1111			urb->status = 0;
1112			*xfer_done = 1;
1113		}
1114	}
1115
1116	return 0;
1117}
1118
1119static int dwc2_process_non_isoc_desc(struct dwc2_hsotg *hsotg,
1120				      struct dwc2_host_chan *chan,
1121				      int chnum, struct dwc2_qtd *qtd,
1122				      int desc_num,
1123				      enum dwc2_halt_status halt_status,
1124				      int *xfer_done)
1125{
1126	struct dwc2_qh *qh = chan->qh;
1127	struct dwc2_hcd_urb *urb = qtd->urb;
1128	struct dwc2_dma_desc *dma_desc;
1129	u32 n_bytes;
1130	int failed;
1131
1132	dev_vdbg(hsotg->dev, "%s()\n", __func__);
1133
1134	if (!urb)
1135		return -EINVAL;
1136
1137	dma_sync_single_for_cpu(hsotg->dev,
1138				qh->desc_list_dma + (desc_num *
1139				sizeof(struct dwc2_dma_desc)),
1140				sizeof(struct dwc2_dma_desc),
1141				DMA_FROM_DEVICE);
1142
1143	dma_desc = &qh->desc_list[desc_num];
1144	n_bytes = qh->n_bytes[desc_num];
1145	dev_vdbg(hsotg->dev,
1146		 "qtd=%p dwc2_urb=%p desc_num=%d desc=%p n_bytes=%d\n",
1147		 qtd, urb, desc_num, dma_desc, n_bytes);
1148	failed = dwc2_update_non_isoc_urb_state_ddma(hsotg, chan, qtd, dma_desc,
1149						     halt_status, n_bytes,
1150						     xfer_done);
1151	if (failed || (*xfer_done && urb->status != -EINPROGRESS)) {
1152		dwc2_host_complete(hsotg, qtd, urb->status);
1153		dwc2_hcd_qtd_unlink_and_free(hsotg, qtd, qh);
1154		dev_vdbg(hsotg->dev, "failed=%1x xfer_done=%1x\n",
1155			 failed, *xfer_done);
1156		return failed;
1157	}
1158
1159	if (qh->ep_type == USB_ENDPOINT_XFER_CONTROL) {
1160		switch (qtd->control_phase) {
1161		case DWC2_CONTROL_SETUP:
1162			if (urb->length > 0)
1163				qtd->control_phase = DWC2_CONTROL_DATA;
1164			else
1165				qtd->control_phase = DWC2_CONTROL_STATUS;
1166			dev_vdbg(hsotg->dev,
1167				 "  Control setup transaction done\n");
1168			break;
1169		case DWC2_CONTROL_DATA:
1170			if (*xfer_done) {
1171				qtd->control_phase = DWC2_CONTROL_STATUS;
1172				dev_vdbg(hsotg->dev,
1173					 "  Control data transfer done\n");
1174			} else if (desc_num + 1 == qtd->n_desc) {
1175				/*
1176				 * Last descriptor for Control data stage which
1177				 * is not completed yet
1178				 */
1179				dwc2_hcd_save_data_toggle(hsotg, chan, chnum,
1180							  qtd);
1181			}
1182			break;
1183		default:
1184			break;
1185		}
1186	}
1187
1188	return 0;
1189}
1190
1191static void dwc2_complete_non_isoc_xfer_ddma(struct dwc2_hsotg *hsotg,
1192					     struct dwc2_host_chan *chan,
1193					     int chnum,
1194					     enum dwc2_halt_status halt_status)
1195{
1196	struct list_head *qtd_item, *qtd_tmp;
1197	struct dwc2_qh *qh = chan->qh;
1198	struct dwc2_qtd *qtd = NULL;
1199	int xfer_done;
1200	int desc_num = 0;
1201
1202	if (chan->halt_status == DWC2_HC_XFER_URB_DEQUEUE) {
1203		list_for_each_entry(qtd, &qh->qtd_list, qtd_list_entry)
1204			qtd->in_process = 0;
1205		return;
1206	}
1207
1208	list_for_each_safe(qtd_item, qtd_tmp, &qh->qtd_list) {
1209		int i;
1210		int qtd_desc_count;
1211
1212		qtd = list_entry(qtd_item, struct dwc2_qtd, qtd_list_entry);
1213		xfer_done = 0;
1214		qtd_desc_count = qtd->n_desc;
1215
1216		for (i = 0; i < qtd_desc_count; i++) {
1217			if (dwc2_process_non_isoc_desc(hsotg, chan, chnum, qtd,
1218						       desc_num, halt_status,
1219						       &xfer_done)) {
1220				qtd = NULL;
1221				goto stop_scan;
1222			}
1223
1224			desc_num++;
1225		}
1226	}
1227
1228stop_scan:
1229	if (qh->ep_type != USB_ENDPOINT_XFER_CONTROL) {
1230		/*
1231		 * Resetting the data toggle for bulk and interrupt endpoints
1232		 * in case of stall. See handle_hc_stall_intr().
1233		 */
1234		if (halt_status == DWC2_HC_XFER_STALL)
1235			qh->data_toggle = DWC2_HC_PID_DATA0;
1236		else
1237			dwc2_hcd_save_data_toggle(hsotg, chan, chnum, NULL);
1238	}
1239
1240	if (halt_status == DWC2_HC_XFER_COMPLETE) {
1241		if (chan->hcint & HCINTMSK_NYET) {
1242			/*
1243			 * Got a NYET on the last transaction of the transfer.
1244			 * It means that the endpoint should be in the PING
1245			 * state at the beginning of the next transfer.
1246			 */
1247			qh->ping_state = 1;
1248		}
1249	}
1250}
1251
1252/**
1253 * dwc2_hcd_complete_xfer_ddma() - Scans the descriptor list, updates URB's
1254 * status and calls completion routine for the URB if it's done. Called from
1255 * interrupt handlers.
1256 *
1257 * @hsotg:       The HCD state structure for the DWC OTG controller
1258 * @chan:        Host channel the transfer is completed on
1259 * @chnum:       Index of Host channel registers
1260 * @halt_status: Reason the channel is being halted or just XferComplete
1261 *               for isochronous transfers
1262 *
1263 * Releases the channel to be used by other transfers.
1264 * In case of Isochronous endpoint the channel is not halted until the end of
1265 * the session, i.e. QTD list is empty.
1266 * If periodic channel released the FrameList is updated accordingly.
1267 * Calls transaction selection routines to activate pending transfers.
1268 */
1269void dwc2_hcd_complete_xfer_ddma(struct dwc2_hsotg *hsotg,
1270				 struct dwc2_host_chan *chan, int chnum,
1271				 enum dwc2_halt_status halt_status)
1272{
1273	struct dwc2_qh *qh = chan->qh;
1274	int continue_isoc_xfer = 0;
1275	enum dwc2_transaction_type tr_type;
1276
1277	if (chan->ep_type == USB_ENDPOINT_XFER_ISOC) {
1278		dwc2_complete_isoc_xfer_ddma(hsotg, chan, halt_status);
1279
1280		/* Release the channel if halted or session completed */
1281		if (halt_status != DWC2_HC_XFER_COMPLETE ||
1282		    list_empty(&qh->qtd_list)) {
1283			struct dwc2_qtd *qtd, *qtd_tmp;
1284
1285			/*
1286			 * Kill all remainings QTDs since channel has been
1287			 * halted.
1288			 */
1289			list_for_each_entry_safe(qtd, qtd_tmp,
1290						 &qh->qtd_list,
1291						 qtd_list_entry) {
1292				dwc2_host_complete(hsotg, qtd,
1293						   -ECONNRESET);
1294				dwc2_hcd_qtd_unlink_and_free(hsotg,
1295							     qtd, qh);
1296			}
1297
1298			/* Halt the channel if session completed */
1299			if (halt_status == DWC2_HC_XFER_COMPLETE)
1300				dwc2_hc_halt(hsotg, chan, halt_status);
1301			dwc2_release_channel_ddma(hsotg, qh);
1302			dwc2_hcd_qh_unlink(hsotg, qh);
1303		} else {
1304			/* Keep in assigned schedule to continue transfer */
1305			list_move_tail(&qh->qh_list_entry,
1306				       &hsotg->periodic_sched_assigned);
1307			/*
1308			 * If channel has been halted during giveback of urb
1309			 * then prevent any new scheduling.
1310			 */
1311			if (!chan->halt_status)
1312				continue_isoc_xfer = 1;
1313		}
1314		/*
1315		 * Todo: Consider the case when period exceeds FrameList size.
1316		 * Frame Rollover interrupt should be used.
1317		 */
1318	} else {
1319		/*
1320		 * Scan descriptor list to complete the URB(s), then release
1321		 * the channel
1322		 */
1323		dwc2_complete_non_isoc_xfer_ddma(hsotg, chan, chnum,
1324						 halt_status);
1325		dwc2_release_channel_ddma(hsotg, qh);
1326		dwc2_hcd_qh_unlink(hsotg, qh);
1327
1328		if (!list_empty(&qh->qtd_list)) {
1329			/*
1330			 * Add back to inactive non-periodic schedule on normal
1331			 * completion
1332			 */
1333			dwc2_hcd_qh_add(hsotg, qh);
1334		}
1335	}
1336
1337	tr_type = dwc2_hcd_select_transactions(hsotg);
1338	if (tr_type != DWC2_TRANSACTION_NONE || continue_isoc_xfer) {
1339		if (continue_isoc_xfer) {
1340			if (tr_type == DWC2_TRANSACTION_NONE)
1341				tr_type = DWC2_TRANSACTION_PERIODIC;
1342			else if (tr_type == DWC2_TRANSACTION_NON_PERIODIC)
1343				tr_type = DWC2_TRANSACTION_ALL;
1344		}
1345		dwc2_hcd_queue_transactions(hsotg, tr_type);
1346	}
1347}