Root/target/linux/adm5120/files/drivers/usb/host/adm5120-q.c

1/*
2 * ADM5120 HCD (Host Controller Driver) for USB
3 *
4 * Copyright (C) 2007-2008 Gabor Juhos <juhosg@openwrt.org>
5 *
6 * This file was derived from: drivers/usb/host/ohci-q.c
7 * (C) Copyright 1999 Roman Weissgaerber <weissg@vienna.at>
8 * (C) Copyright 2000-2002 David Brownell <dbrownell@users.sourceforge.net>
9 *
10 * This program is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU General Public License version 2 as published
12 * by the Free Software Foundation.
13 *
14 */
15
16#include <linux/irq.h>
17
18/*-------------------------------------------------------------------------*/
19
20/*
21 * URB goes back to driver, and isn't reissued.
22 * It's completely gone from HC data structures.
23 * PRECONDITION: ahcd lock held, irqs blocked.
24 */
25static void
26finish_urb(struct admhcd *ahcd, struct urb *urb, int status)
27__releases(ahcd->lock)
28__acquires(ahcd->lock)
29{
30    urb_priv_free(ahcd, urb->hcpriv);
31
32    if (likely(status == -EINPROGRESS))
33        status = 0;
34
35    switch (usb_pipetype(urb->pipe)) {
36    case PIPE_ISOCHRONOUS:
37        admhcd_to_hcd(ahcd)->self.bandwidth_isoc_reqs--;
38        break;
39    case PIPE_INTERRUPT:
40        admhcd_to_hcd(ahcd)->self.bandwidth_int_reqs--;
41        break;
42    }
43
44#ifdef ADMHC_VERBOSE_DEBUG
45    urb_print(ahcd, urb, "RET", usb_pipeout(urb->pipe), status);
46#endif
47
48    /* urb->complete() can reenter this HCD */
49    usb_hcd_unlink_urb_from_ep(admhcd_to_hcd(ahcd), urb);
50    spin_unlock(&ahcd->lock);
51    usb_hcd_giveback_urb(admhcd_to_hcd(ahcd), urb, status);
52    spin_lock(&ahcd->lock);
53}
54
55
56/*-------------------------------------------------------------------------*
57 * ED handling functions
58 *-------------------------------------------------------------------------*/
59
60#if 0 /* FIXME */
61/* search for the right schedule branch to use for a periodic ed.
62 * does some load balancing; returns the branch, or negative errno.
63 */
64static int balance(struct admhcd *ahcd, int interval, int load)
65{
66    int i, branch = -ENOSPC;
67
68    /* iso periods can be huge; iso tds specify frame numbers */
69    if (interval > NUM_INTS)
70        interval = NUM_INTS;
71
72    /* search for the least loaded schedule branch of that period
73     * that has enough bandwidth left unreserved.
74     */
75    for (i = 0; i < interval ; i++) {
76        if (branch < 0 || ahcd->load[branch] > ahcd->load[i]) {
77            int j;
78
79            /* usb 1.1 says 90% of one frame */
80            for (j = i; j < NUM_INTS; j += interval) {
81                if ((ahcd->load[j] + load) > 900)
82                    break;
83            }
84            if (j < NUM_INTS)
85                continue;
86            branch = i;
87        }
88    }
89    return branch;
90}
91#endif
92
93/*-------------------------------------------------------------------------*/
94
95#if 0 /* FIXME */
96/* both iso and interrupt requests have periods; this routine puts them
97 * into the schedule tree in the apppropriate place. most iso devices use
98 * 1msec periods, but that's not required.
99 */
100static void periodic_link(struct admhcd *ahcd, struct ed *ed)
101{
102    unsigned i;
103
104    admhc_vdbg(ahcd, "link %sed %p branch %d [%dus.], interval %d\n",
105        (ed->hwINFO & cpu_to_hc32(ahcd, ED_ISO)) ? "iso " : "",
106        ed, ed->branch, ed->load, ed->interval);
107
108    for (i = ed->branch; i < NUM_INTS; i += ed->interval) {
109        struct ed **prev = &ahcd->periodic[i];
110        __hc32 *prev_p = &ahcd->hcca->int_table[i];
111        struct ed *here = *prev;
112
113        /* sorting each branch by period (slow before fast)
114         * lets us share the faster parts of the tree.
115         * (plus maybe: put interrupt eds before iso)
116         */
117        while (here && ed != here) {
118            if (ed->interval > here->interval)
119                break;
120            prev = &here->ed_next;
121            prev_p = &here->hwNextED;
122            here = *prev;
123        }
124        if (ed != here) {
125            ed->ed_next = here;
126            if (here)
127                ed->hwNextED = *prev_p;
128            wmb();
129            *prev = ed;
130            *prev_p = cpu_to_hc32(ahcd, ed->dma);
131            wmb();
132        }
133        ahcd->load[i] += ed->load;
134    }
135    admhcd_to_hcd(ahcd)->self.bandwidth_allocated += ed->load / ed->interval;
136}
137#endif
138
139/* link an ed into the HC chain */
140
141static int ed_schedule(struct admhcd *ahcd, struct ed *ed)
142{
143    struct ed *old_tail;
144
145    if (admhcd_to_hcd(ahcd)->state == HC_STATE_QUIESCING)
146        return -EAGAIN;
147
148    ed->state = ED_OPER;
149
150    old_tail = ahcd->ed_tails[ed->type];
151
152    ed->ed_next = old_tail->ed_next;
153    if (ed->ed_next) {
154        ed->ed_next->ed_prev = ed;
155        ed->hwNextED = cpu_to_hc32(ahcd, ed->ed_next->dma);
156    }
157    ed->ed_prev = old_tail;
158
159    old_tail->ed_next = ed;
160    old_tail->hwNextED = cpu_to_hc32(ahcd, ed->dma);
161
162    ahcd->ed_tails[ed->type] = ed;
163
164    admhc_dma_enable(ahcd);
165
166    return 0;
167}
168
169/*-------------------------------------------------------------------------*/
170
171#if 0 /* FIXME */
172/* scan the periodic table to find and unlink this ED */
173static void periodic_unlink(struct admhcd *ahcd, struct ed *ed)
174{
175    int i;
176
177    for (i = ed->branch; i < NUM_INTS; i += ed->interval) {
178        struct ed *temp;
179        struct ed **prev = &ahcd->periodic[i];
180        __hc32 *prev_p = &ahcd->hcca->int_table[i];
181
182        while (*prev && (temp = *prev) != ed) {
183            prev_p = &temp->hwNextED;
184            prev = &temp->ed_next;
185        }
186        if (*prev) {
187            *prev_p = ed->hwNextED;
188            *prev = ed->ed_next;
189        }
190        ahcd->load[i] -= ed->load;
191    }
192
193    admhcd_to_hcd(ahcd)->self.bandwidth_allocated -= ed->load / ed->interval;
194    admhc_vdbg(ahcd, "unlink %sed %p branch %d [%dus.], interval %d\n",
195        (ed->hwINFO & cpu_to_hc32(ahcd, ED_ISO)) ? "iso " : "",
196        ed, ed->branch, ed->load, ed->interval);
197}
198#endif
199
200/* unlink an ed from the HC chain.
201 * just the link to the ed is unlinked.
202 * the link from the ed still points to another operational ed or 0
203 * so the HC can eventually finish the processing of the unlinked ed
204 * (assuming it already started that, which needn't be true).
205 *
206 * ED_UNLINK is a transient state: the HC may still see this ED, but soon
207 * it won't. ED_SKIP means the HC will finish its current transaction,
208 * but won't start anything new. The TD queue may still grow; device
209 * drivers don't know about this HCD-internal state.
210 *
211 * When the HC can't see the ED, something changes ED_UNLINK to one of:
212 *
213 * - ED_OPER: when there's any request queued, the ED gets rescheduled
214 * immediately. HC should be working on them.
215 *
216 * - ED_IDLE: when there's no TD queue. there's no reason for the HC
217 * to care about this ED; safe to disable the endpoint.
218 *
219 * When finish_unlinks() runs later, after SOF interrupt, it will often
220 * complete one or more URB unlinks before making that state change.
221 */
222static void ed_deschedule(struct admhcd *ahcd, struct ed *ed)
223{
224
225#ifdef ADMHC_VERBOSE_DEBUG
226    admhc_dump_ed(ahcd, "ED-DESCHED", ed, 1);
227#endif
228
229    ed->hwINFO |= cpu_to_hc32(ahcd, ED_SKIP);
230    wmb();
231    ed->state = ED_UNLINK;
232
233    /* remove this ED from the HC list */
234    ed->ed_prev->hwNextED = ed->hwNextED;
235
236    /* and remove it from our list also */
237    ed->ed_prev->ed_next = ed->ed_next;
238
239    if (ed->ed_next)
240        ed->ed_next->ed_prev = ed->ed_prev;
241
242    if (ahcd->ed_tails[ed->type] == ed)
243        ahcd->ed_tails[ed->type] = ed->ed_prev;
244}
245
246/*-------------------------------------------------------------------------*/
247
248static struct ed *ed_create(struct admhcd *ahcd, unsigned int type, u32 info)
249{
250    struct ed *ed;
251    struct td *td;
252
253    ed = ed_alloc(ahcd, GFP_ATOMIC);
254    if (!ed)
255        goto err;
256
257    /* dummy td; end of td list for this ed */
258    td = td_alloc(ahcd, GFP_ATOMIC);
259    if (!td)
260        goto err_free_ed;
261
262    switch (type) {
263    case PIPE_INTERRUPT:
264        info |= ED_INT;
265        break;
266    case PIPE_ISOCHRONOUS:
267        info |= ED_ISO;
268        break;
269    }
270
271    ed->dummy = td;
272    ed->state = ED_IDLE;
273    ed->type = type;
274
275    ed->hwINFO = cpu_to_hc32(ahcd, info);
276    ed->hwTailP = cpu_to_hc32(ahcd, td->td_dma);
277    ed->hwHeadP = ed->hwTailP; /* ED_C, ED_H zeroed */
278
279    return ed;
280
281err_free_ed:
282    ed_free(ahcd, ed);
283err:
284    return NULL;
285}
286
287/* get and maybe (re)init an endpoint. init _should_ be done only as part
288 * of enumeration, usb_set_configuration() or usb_set_interface().
289 */
290static struct ed *ed_get(struct admhcd *ahcd, struct usb_host_endpoint *ep,
291    struct usb_device *udev, unsigned int pipe, int interval)
292{
293    struct ed *ed;
294    unsigned long flags;
295
296    spin_lock_irqsave(&ahcd->lock, flags);
297
298    ed = ep->hcpriv;
299    if (!ed) {
300        u32 info;
301
302        /* FIXME: usbcore changes dev->devnum before SET_ADDRESS
303         * suceeds ... otherwise we wouldn't need "pipe".
304         */
305        info = usb_pipedevice(pipe);
306        info |= (ep->desc.bEndpointAddress & ~USB_DIR_IN) << ED_EN_SHIFT;
307        info |= le16_to_cpu(ep->desc.wMaxPacketSize) << ED_MPS_SHIFT;
308        if (udev->speed == USB_SPEED_FULL)
309            info |= ED_SPEED_FULL;
310
311        ed = ed_create(ahcd, usb_pipetype(pipe), info);
312        if (ed)
313            ep->hcpriv = ed;
314    }
315
316    spin_unlock_irqrestore(&ahcd->lock, flags);
317
318    return ed;
319}
320
321/*-------------------------------------------------------------------------*/
322
323/* request unlinking of an endpoint from an operational HC.
324 * put the ep on the rm_list
325 * real work is done at the next start frame (SOFI) hardware interrupt
326 * caller guarantees HCD is running, so hardware access is safe,
327 * and that ed->state is ED_OPER
328 */
329static void start_ed_unlink(struct admhcd *ahcd, struct ed *ed)
330{
331
332#ifdef ADMHC_VERBOSE_DEBUG
333    admhc_dump_ed(ahcd, "ED-UNLINK", ed, 1);
334#endif
335
336    ed->hwINFO |= cpu_to_hc32(ahcd, ED_DEQUEUE);
337    ed_deschedule(ahcd, ed);
338
339    /* add this ED into the remove list */
340    ed->ed_rm_next = ahcd->ed_rm_list;
341    ahcd->ed_rm_list = ed;
342
343    /* enable SOF interrupt */
344    admhc_intr_ack(ahcd, ADMHC_INTR_SOFI);
345    admhc_intr_enable(ahcd, ADMHC_INTR_SOFI);
346    /* flush those writes */
347    admhc_writel_flush(ahcd);
348
349    /* SOF interrupt might get delayed; record the frame counter value that
350     * indicates when the HC isn't looking at it, so concurrent unlinks
351     * behave. frame_no wraps every 2^16 msec, and changes right before
352     * SOF is triggered.
353     */
354    ed->tick = admhc_frame_no(ahcd) + 1;
355}
356
357/*-------------------------------------------------------------------------*
358 * TD handling functions
359 *-------------------------------------------------------------------------*/
360
361/* enqueue next TD for this URB (OHCI spec 5.2.8.2) */
362
363static void
364td_fill(struct admhcd *ahcd, u32 info, dma_addr_t data, int len,
365    struct urb *urb, int index)
366{
367    struct td *td, *td_pt;
368    struct urb_priv *urb_priv = urb->hcpriv;
369    int hash;
370    u32 cbl = 0;
371
372#if 1
373    if (index == (urb_priv->td_cnt - 1) &&
374            ((urb->transfer_flags & URB_NO_INTERRUPT) == 0))
375        cbl |= TD_IE;
376#else
377    if (index == (urb_priv->td_cnt - 1))
378        cbl |= TD_IE;
379#endif
380
381    /* use this td as the next dummy */
382    td_pt = urb_priv->td[index];
383
384    /* fill the old dummy TD */
385    td = urb_priv->td[index] = urb_priv->ed->dummy;
386    urb_priv->ed->dummy = td_pt;
387
388    td->ed = urb_priv->ed;
389    td->next_dl_td = NULL;
390    td->index = index;
391    td->urb = urb;
392    td->data_dma = data;
393    if (!len)
394        data = 0;
395
396    if (data)
397        cbl |= (len & TD_BL_MASK);
398
399    info |= TD_OWN;
400
401    /* setup hardware specific fields */
402    td->hwINFO = cpu_to_hc32(ahcd, info);
403    td->hwDBP = cpu_to_hc32(ahcd, data);
404    td->hwCBL = cpu_to_hc32(ahcd, cbl);
405    td->hwNextTD = cpu_to_hc32(ahcd, td_pt->td_dma);
406
407    /* append to queue */
408    list_add_tail(&td->td_list, &td->ed->td_list);
409
410    /* hash it for later reverse mapping */
411    hash = TD_HASH_FUNC(td->td_dma);
412    td->td_hash = ahcd->td_hash[hash];
413    ahcd->td_hash[hash] = td;
414
415    /* HC might read the TD (or cachelines) right away ... */
416    wmb();
417    td->ed->hwTailP = td->hwNextTD;
418}
419
420/*-------------------------------------------------------------------------*/
421
422/* Prepare all TDs of a transfer, and queue them onto the ED.
423 * Caller guarantees HC is active.
424 * Usually the ED is already on the schedule, so TDs might be
425 * processed as soon as they're queued.
426 */
427static void td_submit_urb(struct admhcd *ahcd, struct urb *urb)
428{
429    struct urb_priv *urb_priv = urb->hcpriv;
430    dma_addr_t data;
431    int data_len = urb->transfer_buffer_length;
432    int cnt = 0;
433    u32 info = 0;
434    int is_out = usb_pipeout(urb->pipe);
435    u32 toggle = 0;
436
437    /* OHCI handles the bulk/interrupt data toggles itself. We just
438     * use the device toggle bits for resetting, and rely on the fact
439     * that resetting toggle is meaningless if the endpoint is active.
440     */
441
442    if (usb_gettoggle(urb->dev, usb_pipeendpoint(urb->pipe), is_out)) {
443        toggle = TD_T_CARRY;
444    } else {
445        toggle = TD_T_DATA0;
446        usb_settoggle(urb->dev, usb_pipeendpoint (urb->pipe),
447            is_out, 1);
448    }
449
450    urb_priv->td_idx = 0;
451    list_add(&urb_priv->pending, &ahcd->pending);
452
453    if (data_len)
454        data = urb->transfer_dma;
455    else
456        data = 0;
457
458    /* NOTE: TD_CC is set so we can tell which TDs the HC processed by
459     * using TD_CC_GET, as well as by seeing them on the done list.
460     * (CC = NotAccessed ... 0x0F, or 0x0E in PSWs for ISO.)
461     */
462    switch (urb_priv->ed->type) {
463    case PIPE_INTERRUPT:
464        info = is_out
465            ? TD_T_CARRY | TD_SCC_NOTACCESSED | TD_DP_OUT
466            : TD_T_CARRY | TD_SCC_NOTACCESSED | TD_DP_IN;
467
468        /* setup service interval and starting frame number */
469        info |= (urb->start_frame & TD_FN_MASK);
470        info |= (urb->interval & TD_ISI_MASK) << TD_ISI_SHIFT;
471
472        td_fill(ahcd, info, data, data_len, urb, cnt);
473        cnt++;
474
475        admhcd_to_hcd(ahcd)->self.bandwidth_int_reqs++;
476        break;
477
478    case PIPE_BULK:
479        info = is_out
480            ? TD_SCC_NOTACCESSED | TD_DP_OUT
481            : TD_SCC_NOTACCESSED | TD_DP_IN;
482
483        /* TDs _could_ transfer up to 8K each */
484        while (data_len > TD_DATALEN_MAX) {
485            td_fill(ahcd, info | ((cnt) ? TD_T_CARRY : toggle),
486                data, TD_DATALEN_MAX, urb, cnt);
487            data += TD_DATALEN_MAX;
488            data_len -= TD_DATALEN_MAX;
489            cnt++;
490        }
491
492        td_fill(ahcd, info | ((cnt) ? TD_T_CARRY : toggle), data,
493            data_len, urb, cnt);
494        cnt++;
495
496        if ((urb->transfer_flags & URB_ZERO_PACKET)
497                && (cnt < urb_priv->td_cnt)) {
498            td_fill(ahcd, info | ((cnt) ? TD_T_CARRY : toggle),
499                0, 0, urb, cnt);
500            cnt++;
501        }
502        break;
503
504    /* control manages DATA0/DATA1 toggle per-request; SETUP resets it,
505     * any DATA phase works normally, and the STATUS ack is special.
506     */
507    case PIPE_CONTROL:
508        /* fill a TD for the setup */
509        info = TD_SCC_NOTACCESSED | TD_DP_SETUP | TD_T_DATA0;
510        td_fill(ahcd, info, urb->setup_dma, 8, urb, cnt++);
511
512        if (data_len > 0) {
513            /* fill a TD for the data */
514            info = TD_SCC_NOTACCESSED | TD_T_DATA1;
515            info |= is_out ? TD_DP_OUT : TD_DP_IN;
516            /* NOTE: mishandles transfers >8K, some >4K */
517            td_fill(ahcd, info, data, data_len, urb, cnt++);
518        }
519
520        /* fill a TD for the ACK */
521        info = (is_out || data_len == 0)
522            ? TD_SCC_NOTACCESSED | TD_DP_IN | TD_T_DATA1
523            : TD_SCC_NOTACCESSED | TD_DP_OUT | TD_T_DATA1;
524        td_fill(ahcd, info, data, 0, urb, cnt++);
525
526        break;
527
528    /* ISO has no retransmit, so no toggle;
529     * Each TD could handle multiple consecutive frames (interval 1);
530     * we could often reduce the number of TDs here.
531     */
532    case PIPE_ISOCHRONOUS:
533        info = is_out
534            ? TD_T_CARRY | TD_SCC_NOTACCESSED | TD_DP_OUT
535            : TD_T_CARRY | TD_SCC_NOTACCESSED | TD_DP_IN;
536
537        for (cnt = 0; cnt < urb->number_of_packets; cnt++) {
538            int frame = urb->start_frame;
539
540            frame += cnt * urb->interval;
541            frame &= TD_FN_MASK;
542            td_fill(ahcd, info | frame,
543                data + urb->iso_frame_desc[cnt].offset,
544                urb->iso_frame_desc[cnt].length, urb, cnt);
545        }
546        admhcd_to_hcd(ahcd)->self.bandwidth_isoc_reqs++;
547        break;
548    }
549
550    if (urb_priv->td_cnt != cnt)
551        admhc_err(ahcd, "bad number of tds created for urb %p\n", urb);
552}
553
554/*-------------------------------------------------------------------------*
555 * Done List handling functions
556 *-------------------------------------------------------------------------*/
557
558/* calculate transfer length/status and update the urb */
559static int td_done(struct admhcd *ahcd, struct urb *urb, struct td *td)
560{
561    struct urb_priv *urb_priv = urb->hcpriv;
562    u32 info;
563    u32 bl;
564    u32 tdDBP;
565    int type = usb_pipetype(urb->pipe);
566    int cc;
567    int status = -EINPROGRESS;
568
569    info = hc32_to_cpup(ahcd, &td->hwINFO);
570    tdDBP = hc32_to_cpup(ahcd, &td->hwDBP);
571    bl = TD_BL_GET(hc32_to_cpup(ahcd, &td->hwCBL));
572    cc = TD_CC_GET(info);
573
574    /* ISO ... drivers see per-TD length/status */
575    if (type == PIPE_ISOCHRONOUS) {
576        /* TODO */
577        int dlen = 0;
578
579        /* NOTE: assumes FC in tdINFO == 0, and that
580         * only the first of 0..MAXPSW psws is used.
581         */
582        if (info & TD_CC) /* hc didn't touch? */
583            return status;
584
585        if (usb_pipeout(urb->pipe))
586            dlen = urb->iso_frame_desc[td->index].length;
587        else {
588            /* short reads are always OK for ISO */
589            if (cc == TD_CC_DATAUNDERRUN)
590                cc = TD_CC_NOERROR;
591            dlen = tdDBP - td->data_dma + bl;
592        }
593
594        urb->actual_length += dlen;
595        urb->iso_frame_desc[td->index].actual_length = dlen;
596        urb->iso_frame_desc[td->index].status = cc_to_error[cc];
597
598        if (cc != TD_CC_NOERROR)
599            admhc_vdbg(ahcd,
600                "urb %p iso td %p (%d) len %d cc %d\n",
601                urb, td, 1 + td->index, dlen, cc);
602
603    /* BULK, INT, CONTROL ... drivers see aggregate length/status,
604     * except that "setup" bytes aren't counted and "short" transfers
605     * might not be reported as errors.
606     */
607    } else {
608        /* update packet status if needed (short is normally ok) */
609        if (cc == TD_CC_DATAUNDERRUN
610                && !(urb->transfer_flags & URB_SHORT_NOT_OK))
611            cc = TD_CC_NOERROR;
612
613        if (cc != TD_CC_NOERROR && cc < TD_CC_HCD0)
614            status = cc_to_error[cc];
615
616
617        /* count all non-empty packets except control SETUP packet */
618        if ((type != PIPE_CONTROL || td->index != 0) && tdDBP != 0)
619            urb->actual_length += tdDBP - td->data_dma + bl;
620
621        if (cc != TD_CC_NOERROR && cc < TD_CC_HCD0)
622            admhc_vdbg(ahcd,
623                "urb %p td %p (%d) cc %d, len=%d/%d\n",
624                urb, td, td->index, cc,
625                urb->actual_length,
626                urb->transfer_buffer_length);
627    }
628
629    list_del(&td->td_list);
630    urb_priv->td_idx++;
631
632    return status;
633}
634
635/*-------------------------------------------------------------------------*/
636
637static inline void
638ed_halted(struct admhcd *ahcd, struct td *td, int cc, struct td *rev)
639{
640    struct urb *urb = td->urb;
641    struct urb_priv *urb_priv = urb->hcpriv;
642    struct ed *ed = td->ed;
643    struct list_head *tmp = td->td_list.next;
644    __hc32 toggle = ed->hwHeadP & cpu_to_hc32(ahcd, ED_C);
645
646    admhc_dump_ed(ahcd, "ed halted", td->ed, 1);
647    /* clear ed halt; this is the td that caused it, but keep it inactive
648     * until its urb->complete() has a chance to clean up.
649     */
650    ed->hwINFO |= cpu_to_hc32(ahcd, ED_SKIP);
651    wmb();
652    ed->hwHeadP &= ~cpu_to_hc32(ahcd, ED_H);
653
654    /* Get rid of all later tds from this urb. We don't have
655     * to be careful: no errors and nothing was transferred.
656     * Also patch the ed so it looks as if those tds completed normally.
657     */
658    while (tmp != &ed->td_list) {
659        struct td *next;
660
661        next = list_entry(tmp, struct td, td_list);
662        tmp = next->td_list.next;
663
664        if (next->urb != urb)
665            break;
666
667        /* NOTE: if multi-td control DATA segments get supported,
668         * this urb had one of them, this td wasn't the last td
669         * in that segment (TD_R clear), this ed halted because
670         * of a short read, _and_ URB_SHORT_NOT_OK is clear ...
671         * then we need to leave the control STATUS packet queued
672         * and clear ED_SKIP.
673         */
674        list_del(&next->td_list);
675        urb_priv->td_cnt++;
676        ed->hwHeadP = next->hwNextTD | toggle;
677    }
678
679    /* help for troubleshooting: report anything that
680     * looks odd ... that doesn't include protocol stalls
681     * (or maybe some other things)
682     */
683    switch (cc) {
684    case TD_CC_DATAUNDERRUN:
685        if ((urb->transfer_flags & URB_SHORT_NOT_OK) == 0)
686            break;
687        /* fallthrough */
688    case TD_CC_STALL:
689        if (usb_pipecontrol(urb->pipe))
690            break;
691        /* fallthrough */
692    default:
693        admhc_dbg(ahcd,
694            "urb %p path %s ep%d%s %08x cc %d --> status %d\n",
695            urb, urb->dev->devpath,
696            usb_pipeendpoint (urb->pipe),
697            usb_pipein(urb->pipe) ? "in" : "out",
698            hc32_to_cpu(ahcd, td->hwINFO),
699            cc, cc_to_error[cc]);
700    }
701}
702
703/*-------------------------------------------------------------------------*/
704
705/* there are some urbs/eds to unlink; called in_irq(), with HCD locked */
706static void
707finish_unlinks(struct admhcd *ahcd, u16 tick)
708{
709    struct ed *ed, **last;
710
711rescan_all:
712    for (last = &ahcd->ed_rm_list, ed = *last; ed != NULL; ed = *last) {
713        struct list_head *entry, *tmp;
714        int completed, modified;
715        __hc32 *prev;
716
717        /* only take off EDs that the HC isn't using, accounting for
718         * frame counter wraps and EDs with partially retired TDs
719         */
720        if (likely(HC_IS_RUNNING(admhcd_to_hcd(ahcd)->state))) {
721            if (tick_before(tick, ed->tick)) {
722skip_ed:
723                last = &ed->ed_rm_next;
724                continue;
725            }
726#if 0
727            if (!list_empty(&ed->td_list)) {
728                struct td *td;
729                u32 head;
730
731                td = list_entry(ed->td_list.next, struct td,
732                            td_list);
733                head = hc32_to_cpu(ahcd, ed->hwHeadP) &
734                                TD_MASK;
735
736                /* INTR_WDH may need to clean up first */
737                if (td->td_dma != head)
738                    goto skip_ed;
739            }
740#endif
741        }
742
743        /* reentrancy: if we drop the schedule lock, someone might
744         * have modified this list. normally it's just prepending
745         * entries (which we'd ignore), but paranoia won't hurt.
746         */
747        *last = ed->ed_rm_next;
748        ed->ed_rm_next = NULL;
749        modified = 0;
750
751        /* unlink urbs as requested, but rescan the list after
752         * we call a completion since it might have unlinked
753         * another (earlier) urb
754         *
755         * When we get here, the HC doesn't see this ed. But it
756         * must not be rescheduled until all completed URBs have
757         * been given back to the driver.
758         */
759rescan_this:
760        completed = 0;
761        prev = &ed->hwHeadP;
762        list_for_each_safe(entry, tmp, &ed->td_list) {
763            struct td *td;
764            struct urb *urb;
765            struct urb_priv *urb_priv;
766            __hc32 savebits;
767            int status;
768
769            td = list_entry(entry, struct td, td_list);
770            urb = td->urb;
771            urb_priv = td->urb->hcpriv;
772
773            if (!urb->unlinked) {
774                prev = &td->hwNextTD;
775                continue;
776            }
777
778            if ((urb_priv) == NULL)
779                continue;
780
781            /* patch pointer hc uses */
782            savebits = *prev & ~cpu_to_hc32(ahcd, TD_MASK);
783            *prev = td->hwNextTD | savebits;
784
785            /* HC may have partly processed this TD */
786#ifdef ADMHC_VERBOSE_DEBUG
787            urb_print(ahcd, urb, "PARTIAL", 0);
788#endif
789            status = td_done(ahcd, urb, td);
790
791            /* if URB is done, clean up */
792            if (urb_priv->td_idx == urb_priv->td_cnt) {
793                modified = completed = 1;
794                finish_urb(ahcd, urb, status);
795            }
796        }
797        if (completed && !list_empty(&ed->td_list))
798            goto rescan_this;
799
800        /* ED's now officially unlinked, hc doesn't see */
801        ed->state = ED_IDLE;
802        ed->hwHeadP &= ~cpu_to_hc32(ahcd, ED_H);
803        ed->hwNextED = 0;
804        wmb();
805        ed->hwINFO &= ~cpu_to_hc32(ahcd, ED_SKIP | ED_DEQUEUE);
806
807        /* but if there's work queued, reschedule */
808        if (!list_empty(&ed->td_list)) {
809            if (HC_IS_RUNNING(admhcd_to_hcd(ahcd)->state))
810                ed_schedule(ahcd, ed);
811        }
812
813        if (modified)
814            goto rescan_all;
815    }
816}
817
818/*-------------------------------------------------------------------------*/
819
820/*
821 * Process normal completions (error or success) and clean the schedules.
822 *
823 * This is the main path for handing urbs back to drivers. The only other
824 * path is finish_unlinks(), which unlinks URBs using ed_rm_list, instead of
825 * scanning the (re-reversed) donelist as this does.
826 */
827
828static void ed_unhalt(struct admhcd *ahcd, struct ed *ed, struct urb *urb)
829{
830    struct list_head *entry, *tmp;
831    __hc32 toggle = ed->hwHeadP & cpu_to_hc32(ahcd, ED_C);
832
833#ifdef ADMHC_VERBOSE_DEBUG
834    admhc_dump_ed(ahcd, "UNHALT", ed, 0);
835#endif
836    /* clear ed halt; this is the td that caused it, but keep it inactive
837     * until its urb->complete() has a chance to clean up.
838     */
839    ed->hwINFO |= cpu_to_hc32(ahcd, ED_SKIP);
840    wmb();
841    ed->hwHeadP &= ~cpu_to_hc32(ahcd, ED_H);
842
843    list_for_each_safe(entry, tmp, &ed->td_list) {
844        struct td *td = list_entry(entry, struct td, td_list);
845        __hc32 info;
846
847        if (td->urb != urb)
848            break;
849
850        info = td->hwINFO;
851        info &= ~cpu_to_hc32(ahcd, TD_CC | TD_OWN);
852        td->hwINFO = info;
853
854        ed->hwHeadP = td->hwNextTD | toggle;
855        wmb();
856    }
857
858}
859
860static void ed_intr_refill(struct admhcd *ahcd, struct ed *ed)
861{
862    __hc32 toggle = ed->hwHeadP & cpu_to_hc32(ahcd, ED_C);
863
864    ed->hwHeadP = ed->hwTailP | toggle;
865}
866
867
868static inline int is_ed_halted(struct admhcd *ahcd, struct ed *ed)
869{
870    return ((hc32_to_cpup(ahcd, &ed->hwHeadP) & ED_H) == ED_H);
871}
872
873static inline int is_td_halted(struct admhcd *ahcd, struct ed *ed,
874        struct td *td)
875{
876    return ((hc32_to_cpup(ahcd, &ed->hwHeadP) & TD_MASK) ==
877        (hc32_to_cpup(ahcd, &td->hwNextTD) & TD_MASK));
878}
879
880static void ed_update(struct admhcd *ahcd, struct ed *ed)
881{
882    struct list_head *entry, *tmp;
883
884#ifdef ADMHC_VERBOSE_DEBUG
885    admhc_dump_ed(ahcd, "UPDATE", ed, 1);
886#endif
887
888    list_for_each_safe(entry, tmp, &ed->td_list) {
889        struct td *td = list_entry(entry, struct td, td_list);
890        struct urb *urb = td->urb;
891        struct urb_priv *urb_priv = urb->hcpriv;
892        int status;
893
894        if (hc32_to_cpup(ahcd, &td->hwINFO) & TD_OWN)
895            break;
896
897        /* update URB's length and status from TD */
898        status = td_done(ahcd, urb, td);
899        if (is_ed_halted(ahcd, ed) && is_td_halted(ahcd, ed, td))
900            ed_unhalt(ahcd, ed, urb);
901
902        if (ed->type == PIPE_INTERRUPT)
903            ed_intr_refill(ahcd, ed);
904
905        /* If all this urb's TDs are done, call complete() */
906        if (urb_priv->td_idx == urb_priv->td_cnt)
907            finish_urb(ahcd, urb, status);
908
909        /* clean schedule: unlink EDs that are no longer busy */
910        if (list_empty(&ed->td_list)) {
911            if (ed->state == ED_OPER)
912                start_ed_unlink(ahcd, ed);
913
914        /* ... reenabling halted EDs only after fault cleanup */
915        } else if ((ed->hwINFO & cpu_to_hc32(ahcd,
916                        ED_SKIP | ED_DEQUEUE))
917                    == cpu_to_hc32(ahcd, ED_SKIP)) {
918            td = list_entry(ed->td_list.next, struct td, td_list);
919#if 0
920            if (!(td->hwINFO & cpu_to_hc32(ahcd, TD_DONE))) {
921                ed->hwINFO &= ~cpu_to_hc32(ahcd, ED_SKIP);
922                /* ... hc may need waking-up */
923                switch (ed->type) {
924                case PIPE_CONTROL:
925                    admhc_writel(ahcd, OHCI_CLF,
926                        &ahcd->regs->cmdstatus);
927                    break;
928                case PIPE_BULK:
929                    admhc_writel(ahcd, OHCI_BLF,
930                        &ahcd->regs->cmdstatus);
931                    break;
932                }
933            }
934#else
935            if ((td->hwINFO & cpu_to_hc32(ahcd, TD_OWN)))
936                ed->hwINFO &= ~cpu_to_hc32(ahcd, ED_SKIP);
937#endif
938        }
939
940    }
941}
942
943/* there are some tds completed; called in_irq(), with HCD locked */
944static void admhc_td_complete(struct admhcd *ahcd)
945{
946    struct ed *ed;
947
948    for (ed = ahcd->ed_head; ed; ed = ed->ed_next) {
949        if (ed->state != ED_OPER)
950            continue;
951
952        ed_update(ahcd, ed);
953    }
954}
955

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