[PATCH] UHCI: Improve FSBR-off timing
[safe/jmp/linux-2.6] / drivers / usb / host / uhci-hcd.c
1 /*
2  * Universal Host Controller Interface driver for USB.
3  *
4  * Maintainer: Alan Stern <stern@rowland.harvard.edu>
5  *
6  * (C) Copyright 1999 Linus Torvalds
7  * (C) Copyright 1999-2002 Johannes Erdfelt, johannes@erdfelt.com
8  * (C) Copyright 1999 Randy Dunlap
9  * (C) Copyright 1999 Georg Acher, acher@in.tum.de
10  * (C) Copyright 1999 Deti Fliegl, deti@fliegl.de
11  * (C) Copyright 1999 Thomas Sailer, sailer@ife.ee.ethz.ch
12  * (C) Copyright 1999 Roman Weissgaerber, weissg@vienna.at
13  * (C) Copyright 2000 Yggdrasil Computing, Inc. (port of new PCI interface
14  *               support from usb-ohci.c by Adam Richter, adam@yggdrasil.com).
15  * (C) Copyright 1999 Gregory P. Smith (from usb-ohci.c)
16  * (C) Copyright 2004-2006 Alan Stern, stern@rowland.harvard.edu
17  *
18  * Intel documents this fairly well, and as far as I know there
19  * are no royalties or anything like that, but even so there are
20  * people who decided that they want to do the same thing in a
21  * completely different way.
22  *
23  */
24
25 #include <linux/config.h>
26 #include <linux/module.h>
27 #include <linux/pci.h>
28 #include <linux/kernel.h>
29 #include <linux/init.h>
30 #include <linux/delay.h>
31 #include <linux/ioport.h>
32 #include <linux/sched.h>
33 #include <linux/slab.h>
34 #include <linux/errno.h>
35 #include <linux/unistd.h>
36 #include <linux/interrupt.h>
37 #include <linux/spinlock.h>
38 #include <linux/debugfs.h>
39 #include <linux/pm.h>
40 #include <linux/dmapool.h>
41 #include <linux/dma-mapping.h>
42 #include <linux/usb.h>
43 #include <linux/bitops.h>
44
45 #include <asm/uaccess.h>
46 #include <asm/io.h>
47 #include <asm/irq.h>
48 #include <asm/system.h>
49
50 #include "../core/hcd.h"
51 #include "uhci-hcd.h"
52 #include "pci-quirks.h"
53
54 /*
55  * Version Information
56  */
57 #define DRIVER_VERSION "v3.0"
58 #define DRIVER_AUTHOR "Linus 'Frodo Rabbit' Torvalds, Johannes Erdfelt, \
59 Randy Dunlap, Georg Acher, Deti Fliegl, Thomas Sailer, Roman Weissgaerber, \
60 Alan Stern"
61 #define DRIVER_DESC "USB Universal Host Controller Interface driver"
62
63 /*
64  * debug = 0, no debugging messages
65  * debug = 1, dump failed URBs except for stalls
66  * debug = 2, dump all failed URBs (including stalls)
67  *            show all queues in /debug/uhci/[pci_addr]
68  * debug = 3, show all TDs in URBs when dumping
69  */
70 #ifdef DEBUG
71 #define DEBUG_CONFIGURED        1
72 static int debug = 1;
73 module_param(debug, int, S_IRUGO | S_IWUSR);
74 MODULE_PARM_DESC(debug, "Debug level");
75
76 #else
77 #define DEBUG_CONFIGURED        0
78 #define debug                   0
79 #endif
80
81 static char *errbuf;
82 #define ERRBUF_LEN    (32 * 1024)
83
84 static kmem_cache_t *uhci_up_cachep;    /* urb_priv */
85
86 static void suspend_rh(struct uhci_hcd *uhci, enum uhci_rh_state new_state);
87 static void wakeup_rh(struct uhci_hcd *uhci);
88 static void uhci_get_current_frame_number(struct uhci_hcd *uhci);
89
90 #include "uhci-debug.c"
91 #include "uhci-q.c"
92 #include "uhci-hub.c"
93
94 /*
95  * Finish up a host controller reset and update the recorded state.
96  */
97 static void finish_reset(struct uhci_hcd *uhci)
98 {
99         int port;
100
101         /* HCRESET doesn't affect the Suspend, Reset, and Resume Detect
102          * bits in the port status and control registers.
103          * We have to clear them by hand.
104          */
105         for (port = 0; port < uhci->rh_numports; ++port)
106                 outw(0, uhci->io_addr + USBPORTSC1 + (port * 2));
107
108         uhci->port_c_suspend = uhci->resuming_ports = 0;
109         uhci->rh_state = UHCI_RH_RESET;
110         uhci->is_stopped = UHCI_IS_STOPPED;
111         uhci_to_hcd(uhci)->state = HC_STATE_HALT;
112         uhci_to_hcd(uhci)->poll_rh = 0;
113
114         uhci->dead = 0;         /* Full reset resurrects the controller */
115 }
116
117 /*
118  * Last rites for a defunct/nonfunctional controller
119  * or one we don't want to use any more.
120  */
121 static void uhci_hc_died(struct uhci_hcd *uhci)
122 {
123         uhci_get_current_frame_number(uhci);
124         uhci_reset_hc(to_pci_dev(uhci_dev(uhci)), uhci->io_addr);
125         finish_reset(uhci);
126         uhci->dead = 1;
127
128         /* The current frame may already be partway finished */
129         ++uhci->frame_number;
130 }
131
132 /*
133  * Initialize a controller that was newly discovered or has lost power
134  * or otherwise been reset while it was suspended.  In none of these cases
135  * can we be sure of its previous state.
136  */
137 static void check_and_reset_hc(struct uhci_hcd *uhci)
138 {
139         if (uhci_check_and_reset_hc(to_pci_dev(uhci_dev(uhci)), uhci->io_addr))
140                 finish_reset(uhci);
141 }
142
143 /*
144  * Store the basic register settings needed by the controller.
145  */
146 static void configure_hc(struct uhci_hcd *uhci)
147 {
148         /* Set the frame length to the default: 1 ms exactly */
149         outb(USBSOF_DEFAULT, uhci->io_addr + USBSOF);
150
151         /* Store the frame list base address */
152         outl(uhci->frame_dma_handle, uhci->io_addr + USBFLBASEADD);
153
154         /* Set the current frame number */
155         outw(uhci->frame_number & UHCI_MAX_SOF_NUMBER,
156                         uhci->io_addr + USBFRNUM);
157
158         /* Mark controller as not halted before we enable interrupts */
159         uhci_to_hcd(uhci)->state = HC_STATE_SUSPENDED;
160         mb();
161
162         /* Enable PIRQ */
163         pci_write_config_word(to_pci_dev(uhci_dev(uhci)), USBLEGSUP,
164                         USBLEGSUP_DEFAULT);
165 }
166
167
168 static int resume_detect_interrupts_are_broken(struct uhci_hcd *uhci)
169 {
170         int port;
171
172         switch (to_pci_dev(uhci_dev(uhci))->vendor) {
173             default:
174                 break;
175
176             case PCI_VENDOR_ID_GENESYS:
177                 /* Genesys Logic's GL880S controllers don't generate
178                  * resume-detect interrupts.
179                  */
180                 return 1;
181
182             case PCI_VENDOR_ID_INTEL:
183                 /* Some of Intel's USB controllers have a bug that causes
184                  * resume-detect interrupts if any port has an over-current
185                  * condition.  To make matters worse, some motherboards
186                  * hardwire unused USB ports' over-current inputs active!
187                  * To prevent problems, we will not enable resume-detect
188                  * interrupts if any ports are OC.
189                  */
190                 for (port = 0; port < uhci->rh_numports; ++port) {
191                         if (inw(uhci->io_addr + USBPORTSC1 + port * 2) &
192                                         USBPORTSC_OC)
193                                 return 1;
194                 }
195                 break;
196         }
197         return 0;
198 }
199
200 static void suspend_rh(struct uhci_hcd *uhci, enum uhci_rh_state new_state)
201 __releases(uhci->lock)
202 __acquires(uhci->lock)
203 {
204         int auto_stop;
205         int int_enable;
206
207         auto_stop = (new_state == UHCI_RH_AUTO_STOPPED);
208         dev_dbg(&uhci_to_hcd(uhci)->self.root_hub->dev,
209                         "%s%s\n", __FUNCTION__,
210                         (auto_stop ? " (auto-stop)" : ""));
211
212         /* If we get a suspend request when we're already auto-stopped
213          * then there's nothing to do.
214          */
215         if (uhci->rh_state == UHCI_RH_AUTO_STOPPED) {
216                 uhci->rh_state = new_state;
217                 return;
218         }
219
220         /* Enable resume-detect interrupts if they work.
221          * Then enter Global Suspend mode, still configured.
222          */
223         uhci->working_RD = 1;
224         int_enable = USBINTR_RESUME;
225         if (resume_detect_interrupts_are_broken(uhci)) {
226                 uhci->working_RD = int_enable = 0;
227         }
228         outw(int_enable, uhci->io_addr + USBINTR);
229         outw(USBCMD_EGSM | USBCMD_CF, uhci->io_addr + USBCMD);
230         mb();
231         udelay(5);
232
233         /* If we're auto-stopping then no devices have been attached
234          * for a while, so there shouldn't be any active URBs and the
235          * controller should stop after a few microseconds.  Otherwise
236          * we will give the controller one frame to stop.
237          */
238         if (!auto_stop && !(inw(uhci->io_addr + USBSTS) & USBSTS_HCH)) {
239                 uhci->rh_state = UHCI_RH_SUSPENDING;
240                 spin_unlock_irq(&uhci->lock);
241                 msleep(1);
242                 spin_lock_irq(&uhci->lock);
243                 if (uhci->dead)
244                         return;
245         }
246         if (!(inw(uhci->io_addr + USBSTS) & USBSTS_HCH))
247                 dev_warn(&uhci_to_hcd(uhci)->self.root_hub->dev,
248                         "Controller not stopped yet!\n");
249
250         uhci_get_current_frame_number(uhci);
251
252         uhci->rh_state = new_state;
253         uhci->is_stopped = UHCI_IS_STOPPED;
254         uhci_to_hcd(uhci)->poll_rh = !int_enable;
255
256         uhci_scan_schedule(uhci, NULL);
257         uhci_fsbr_off(uhci);
258 }
259
260 static void start_rh(struct uhci_hcd *uhci)
261 {
262         uhci_to_hcd(uhci)->state = HC_STATE_RUNNING;
263         uhci->is_stopped = 0;
264
265         /* Mark it configured and running with a 64-byte max packet.
266          * All interrupts are enabled, even though RESUME won't do anything.
267          */
268         outw(USBCMD_RS | USBCMD_CF | USBCMD_MAXP, uhci->io_addr + USBCMD);
269         outw(USBINTR_TIMEOUT | USBINTR_RESUME | USBINTR_IOC | USBINTR_SP,
270                         uhci->io_addr + USBINTR);
271         mb();
272         uhci->rh_state = UHCI_RH_RUNNING;
273         uhci_to_hcd(uhci)->poll_rh = 1;
274 }
275
276 static void wakeup_rh(struct uhci_hcd *uhci)
277 __releases(uhci->lock)
278 __acquires(uhci->lock)
279 {
280         dev_dbg(&uhci_to_hcd(uhci)->self.root_hub->dev,
281                         "%s%s\n", __FUNCTION__,
282                         uhci->rh_state == UHCI_RH_AUTO_STOPPED ?
283                                 " (auto-start)" : "");
284
285         /* If we are auto-stopped then no devices are attached so there's
286          * no need for wakeup signals.  Otherwise we send Global Resume
287          * for 20 ms.
288          */
289         if (uhci->rh_state == UHCI_RH_SUSPENDED) {
290                 uhci->rh_state = UHCI_RH_RESUMING;
291                 outw(USBCMD_FGR | USBCMD_EGSM | USBCMD_CF,
292                                 uhci->io_addr + USBCMD);
293                 spin_unlock_irq(&uhci->lock);
294                 msleep(20);
295                 spin_lock_irq(&uhci->lock);
296                 if (uhci->dead)
297                         return;
298
299                 /* End Global Resume and wait for EOP to be sent */
300                 outw(USBCMD_CF, uhci->io_addr + USBCMD);
301                 mb();
302                 udelay(4);
303                 if (inw(uhci->io_addr + USBCMD) & USBCMD_FGR)
304                         dev_warn(uhci_dev(uhci), "FGR not stopped yet!\n");
305         }
306
307         start_rh(uhci);
308
309         /* Restart root hub polling */
310         mod_timer(&uhci_to_hcd(uhci)->rh_timer, jiffies);
311 }
312
313 static irqreturn_t uhci_irq(struct usb_hcd *hcd, struct pt_regs *regs)
314 {
315         struct uhci_hcd *uhci = hcd_to_uhci(hcd);
316         unsigned short status;
317         unsigned long flags;
318
319         /*
320          * Read the interrupt status, and write it back to clear the
321          * interrupt cause.  Contrary to the UHCI specification, the
322          * "HC Halted" status bit is persistent: it is RO, not R/WC.
323          */
324         status = inw(uhci->io_addr + USBSTS);
325         if (!(status & ~USBSTS_HCH))    /* shared interrupt, not mine */
326                 return IRQ_NONE;
327         outw(status, uhci->io_addr + USBSTS);           /* Clear it */
328
329         if (status & ~(USBSTS_USBINT | USBSTS_ERROR | USBSTS_RD)) {
330                 if (status & USBSTS_HSE)
331                         dev_err(uhci_dev(uhci), "host system error, "
332                                         "PCI problems?\n");
333                 if (status & USBSTS_HCPE)
334                         dev_err(uhci_dev(uhci), "host controller process "
335                                         "error, something bad happened!\n");
336                 if (status & USBSTS_HCH) {
337                         spin_lock_irqsave(&uhci->lock, flags);
338                         if (uhci->rh_state >= UHCI_RH_RUNNING) {
339                                 dev_err(uhci_dev(uhci),
340                                         "host controller halted, "
341                                         "very bad!\n");
342                                 if (debug > 1 && errbuf) {
343                                         /* Print the schedule for debugging */
344                                         uhci_sprint_schedule(uhci,
345                                                         errbuf, ERRBUF_LEN);
346                                         lprintk(errbuf);
347                                 }
348                                 uhci_hc_died(uhci);
349
350                                 /* Force a callback in case there are
351                                  * pending unlinks */
352                                 mod_timer(&hcd->rh_timer, jiffies);
353                         }
354                         spin_unlock_irqrestore(&uhci->lock, flags);
355                 }
356         }
357
358         if (status & USBSTS_RD)
359                 usb_hcd_poll_rh_status(hcd);
360         else {
361                 spin_lock_irqsave(&uhci->lock, flags);
362                 uhci_scan_schedule(uhci, regs);
363                 spin_unlock_irqrestore(&uhci->lock, flags);
364         }
365
366         return IRQ_HANDLED;
367 }
368
369 /*
370  * Store the current frame number in uhci->frame_number if the controller
371  * is runnning.  Expand from 11 bits (of which we use only 10) to a
372  * full-sized integer.
373  *
374  * Like many other parts of the driver, this code relies on being polled
375  * more than once per second as long as the controller is running.
376  */
377 static void uhci_get_current_frame_number(struct uhci_hcd *uhci)
378 {
379         if (!uhci->is_stopped) {
380                 unsigned delta;
381
382                 delta = (inw(uhci->io_addr + USBFRNUM) - uhci->frame_number) &
383                                 (UHCI_NUMFRAMES - 1);
384                 uhci->frame_number += delta;
385         }
386 }
387
388 /*
389  * De-allocate all resources
390  */
391 static void release_uhci(struct uhci_hcd *uhci)
392 {
393         int i;
394
395         if (DEBUG_CONFIGURED) {
396                 spin_lock_irq(&uhci->lock);
397                 uhci->is_initialized = 0;
398                 spin_unlock_irq(&uhci->lock);
399
400                 debugfs_remove(uhci->dentry);
401         }
402
403         for (i = 0; i < UHCI_NUM_SKELQH; i++)
404                 uhci_free_qh(uhci, uhci->skelqh[i]);
405
406         uhci_free_td(uhci, uhci->term_td);
407
408         dma_pool_destroy(uhci->qh_pool);
409
410         dma_pool_destroy(uhci->td_pool);
411
412         kfree(uhci->frame_cpu);
413
414         dma_free_coherent(uhci_dev(uhci),
415                         UHCI_NUMFRAMES * sizeof(*uhci->frame),
416                         uhci->frame, uhci->frame_dma_handle);
417 }
418
419 static int uhci_init(struct usb_hcd *hcd)
420 {
421         struct uhci_hcd *uhci = hcd_to_uhci(hcd);
422         unsigned io_size = (unsigned) hcd->rsrc_len;
423         int port;
424
425         uhci->io_addr = (unsigned long) hcd->rsrc_start;
426
427         /* The UHCI spec says devices must have 2 ports, and goes on to say
428          * they may have more but gives no way to determine how many there
429          * are.  However according to the UHCI spec, Bit 7 of the port
430          * status and control register is always set to 1.  So we try to
431          * use this to our advantage.  Another common failure mode when
432          * a nonexistent register is addressed is to return all ones, so
433          * we test for that also.
434          */
435         for (port = 0; port < (io_size - USBPORTSC1) / 2; port++) {
436                 unsigned int portstatus;
437
438                 portstatus = inw(uhci->io_addr + USBPORTSC1 + (port * 2));
439                 if (!(portstatus & 0x0080) || portstatus == 0xffff)
440                         break;
441         }
442         if (debug)
443                 dev_info(uhci_dev(uhci), "detected %d ports\n", port);
444
445         /* Anything greater than 7 is weird so we'll ignore it. */
446         if (port > UHCI_RH_MAXCHILD) {
447                 dev_info(uhci_dev(uhci), "port count misdetected? "
448                                 "forcing to 2 ports\n");
449                 port = 2;
450         }
451         uhci->rh_numports = port;
452
453         /* Kick BIOS off this hardware and reset if the controller
454          * isn't already safely quiescent.
455          */
456         check_and_reset_hc(uhci);
457         return 0;
458 }
459
460 /* Make sure the controller is quiescent and that we're not using it
461  * any more.  This is mainly for the benefit of programs which, like kexec,
462  * expect the hardware to be idle: not doing DMA or generating IRQs.
463  *
464  * This routine may be called in a damaged or failing kernel.  Hence we
465  * do not acquire the spinlock before shutting down the controller.
466  */
467 static void uhci_shutdown(struct pci_dev *pdev)
468 {
469         struct usb_hcd *hcd = (struct usb_hcd *) pci_get_drvdata(pdev);
470
471         uhci_hc_died(hcd_to_uhci(hcd));
472 }
473
474 /*
475  * Allocate a frame list, and then setup the skeleton
476  *
477  * The hardware doesn't really know any difference
478  * in the queues, but the order does matter for the
479  * protocols higher up. The order is:
480  *
481  *  - any isochronous events handled before any
482  *    of the queues. We don't do that here, because
483  *    we'll create the actual TD entries on demand.
484  *  - The first queue is the interrupt queue.
485  *  - The second queue is the control queue, split into low- and full-speed
486  *  - The third queue is bulk queue.
487  *  - The fourth queue is the bandwidth reclamation queue, which loops back
488  *    to the full-speed control queue.
489  */
490 static int uhci_start(struct usb_hcd *hcd)
491 {
492         struct uhci_hcd *uhci = hcd_to_uhci(hcd);
493         int retval = -EBUSY;
494         int i;
495         struct dentry *dentry;
496
497         hcd->uses_new_polling = 1;
498
499         spin_lock_init(&uhci->lock);
500         setup_timer(&uhci->fsbr_timer, uhci_fsbr_timeout,
501                         (unsigned long) uhci);
502         INIT_LIST_HEAD(&uhci->idle_qh_list);
503         init_waitqueue_head(&uhci->waitqh);
504
505         if (DEBUG_CONFIGURED) {
506                 dentry = debugfs_create_file(hcd->self.bus_name,
507                                 S_IFREG|S_IRUGO|S_IWUSR, uhci_debugfs_root,
508                                 uhci, &uhci_debug_operations);
509                 if (!dentry) {
510                         dev_err(uhci_dev(uhci), "couldn't create uhci "
511                                         "debugfs entry\n");
512                         retval = -ENOMEM;
513                         goto err_create_debug_entry;
514                 }
515                 uhci->dentry = dentry;
516         }
517
518         uhci->frame = dma_alloc_coherent(uhci_dev(uhci),
519                         UHCI_NUMFRAMES * sizeof(*uhci->frame),
520                         &uhci->frame_dma_handle, 0);
521         if (!uhci->frame) {
522                 dev_err(uhci_dev(uhci), "unable to allocate "
523                                 "consistent memory for frame list\n");
524                 goto err_alloc_frame;
525         }
526         memset(uhci->frame, 0, UHCI_NUMFRAMES * sizeof(*uhci->frame));
527
528         uhci->frame_cpu = kcalloc(UHCI_NUMFRAMES, sizeof(*uhci->frame_cpu),
529                         GFP_KERNEL);
530         if (!uhci->frame_cpu) {
531                 dev_err(uhci_dev(uhci), "unable to allocate "
532                                 "memory for frame pointers\n");
533                 goto err_alloc_frame_cpu;
534         }
535
536         uhci->td_pool = dma_pool_create("uhci_td", uhci_dev(uhci),
537                         sizeof(struct uhci_td), 16, 0);
538         if (!uhci->td_pool) {
539                 dev_err(uhci_dev(uhci), "unable to create td dma_pool\n");
540                 goto err_create_td_pool;
541         }
542
543         uhci->qh_pool = dma_pool_create("uhci_qh", uhci_dev(uhci),
544                         sizeof(struct uhci_qh), 16, 0);
545         if (!uhci->qh_pool) {
546                 dev_err(uhci_dev(uhci), "unable to create qh dma_pool\n");
547                 goto err_create_qh_pool;
548         }
549
550         uhci->term_td = uhci_alloc_td(uhci);
551         if (!uhci->term_td) {
552                 dev_err(uhci_dev(uhci), "unable to allocate terminating TD\n");
553                 goto err_alloc_term_td;
554         }
555
556         for (i = 0; i < UHCI_NUM_SKELQH; i++) {
557                 uhci->skelqh[i] = uhci_alloc_qh(uhci, NULL, NULL);
558                 if (!uhci->skelqh[i]) {
559                         dev_err(uhci_dev(uhci), "unable to allocate QH\n");
560                         goto err_alloc_skelqh;
561                 }
562         }
563
564         /*
565          * 8 Interrupt queues; link all higher int queues to int1,
566          * then link int1 to control and control to bulk
567          */
568         uhci->skel_int128_qh->link =
569                         uhci->skel_int64_qh->link =
570                         uhci->skel_int32_qh->link =
571                         uhci->skel_int16_qh->link =
572                         uhci->skel_int8_qh->link =
573                         uhci->skel_int4_qh->link =
574                         uhci->skel_int2_qh->link = UHCI_PTR_QH |
575                         cpu_to_le32(uhci->skel_int1_qh->dma_handle);
576
577         uhci->skel_int1_qh->link = UHCI_PTR_QH |
578                         cpu_to_le32(uhci->skel_ls_control_qh->dma_handle);
579         uhci->skel_ls_control_qh->link = UHCI_PTR_QH |
580                         cpu_to_le32(uhci->skel_fs_control_qh->dma_handle);
581         uhci->skel_fs_control_qh->link = UHCI_PTR_QH |
582                         cpu_to_le32(uhci->skel_bulk_qh->dma_handle);
583         uhci->skel_bulk_qh->link = UHCI_PTR_QH |
584                         cpu_to_le32(uhci->skel_term_qh->dma_handle);
585
586         /* This dummy TD is to work around a bug in Intel PIIX controllers */
587         uhci_fill_td(uhci->term_td, 0, uhci_explen(0) |
588                 (0x7f << TD_TOKEN_DEVADDR_SHIFT) | USB_PID_IN, 0);
589         uhci->term_td->link = cpu_to_le32(uhci->term_td->dma_handle);
590
591         uhci->skel_term_qh->link = UHCI_PTR_TERM;
592         uhci->skel_term_qh->element = cpu_to_le32(uhci->term_td->dma_handle);
593
594         /*
595          * Fill the frame list: make all entries point to the proper
596          * interrupt queue.
597          *
598          * The interrupt queues will be interleaved as evenly as possible.
599          * There's not much to be done about period-1 interrupts; they have
600          * to occur in every frame.  But we can schedule period-2 interrupts
601          * in odd-numbered frames, period-4 interrupts in frames congruent
602          * to 2 (mod 4), and so on.  This way each frame only has two
603          * interrupt QHs, which will help spread out bandwidth utilization.
604          */
605         for (i = 0; i < UHCI_NUMFRAMES; i++) {
606                 int irq;
607
608                 /*
609                  * ffs (Find First bit Set) does exactly what we need:
610                  * 1,3,5,...  => ffs = 0 => use skel_int2_qh = skelqh[8],
611                  * 2,6,10,... => ffs = 1 => use skel_int4_qh = skelqh[7], etc.
612                  * ffs >= 7 => not on any high-period queue, so use
613                  *      skel_int1_qh = skelqh[9].
614                  * Add UHCI_NUMFRAMES to insure at least one bit is set.
615                  */
616                 irq = 8 - (int) __ffs(i + UHCI_NUMFRAMES);
617                 if (irq <= 1)
618                         irq = 9;
619
620                 /* Only place we don't use the frame list routines */
621                 uhci->frame[i] = UHCI_PTR_QH |
622                                 cpu_to_le32(uhci->skelqh[irq]->dma_handle);
623         }
624
625         /*
626          * Some architectures require a full mb() to enforce completion of
627          * the memory writes above before the I/O transfers in configure_hc().
628          */
629         mb();
630
631         configure_hc(uhci);
632         uhci->is_initialized = 1;
633         start_rh(uhci);
634         return 0;
635
636 /*
637  * error exits:
638  */
639 err_alloc_skelqh:
640         for (i = 0; i < UHCI_NUM_SKELQH; i++) {
641                 if (uhci->skelqh[i])
642                         uhci_free_qh(uhci, uhci->skelqh[i]);
643         }
644
645         uhci_free_td(uhci, uhci->term_td);
646
647 err_alloc_term_td:
648         dma_pool_destroy(uhci->qh_pool);
649
650 err_create_qh_pool:
651         dma_pool_destroy(uhci->td_pool);
652
653 err_create_td_pool:
654         kfree(uhci->frame_cpu);
655
656 err_alloc_frame_cpu:
657         dma_free_coherent(uhci_dev(uhci),
658                         UHCI_NUMFRAMES * sizeof(*uhci->frame),
659                         uhci->frame, uhci->frame_dma_handle);
660
661 err_alloc_frame:
662         debugfs_remove(uhci->dentry);
663
664 err_create_debug_entry:
665         return retval;
666 }
667
668 static void uhci_stop(struct usb_hcd *hcd)
669 {
670         struct uhci_hcd *uhci = hcd_to_uhci(hcd);
671
672         spin_lock_irq(&uhci->lock);
673         if (test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags) && !uhci->dead)
674                 uhci_hc_died(uhci);
675         uhci_scan_schedule(uhci, NULL);
676         spin_unlock_irq(&uhci->lock);
677
678         del_timer_sync(&uhci->fsbr_timer);
679         release_uhci(uhci);
680 }
681
682 #ifdef CONFIG_PM
683 static int uhci_rh_suspend(struct usb_hcd *hcd)
684 {
685         struct uhci_hcd *uhci = hcd_to_uhci(hcd);
686         int rc = 0;
687
688         spin_lock_irq(&uhci->lock);
689         if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags))
690                 rc = -ESHUTDOWN;
691         else if (!uhci->dead)
692                 suspend_rh(uhci, UHCI_RH_SUSPENDED);
693         spin_unlock_irq(&uhci->lock);
694         return rc;
695 }
696
697 static int uhci_rh_resume(struct usb_hcd *hcd)
698 {
699         struct uhci_hcd *uhci = hcd_to_uhci(hcd);
700         int rc = 0;
701
702         spin_lock_irq(&uhci->lock);
703         if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags)) {
704                 dev_warn(&hcd->self.root_hub->dev, "HC isn't running!\n");
705                 rc = -ESHUTDOWN;
706         } else if (!uhci->dead)
707                 wakeup_rh(uhci);
708         spin_unlock_irq(&uhci->lock);
709         return rc;
710 }
711
712 static int uhci_suspend(struct usb_hcd *hcd, pm_message_t message)
713 {
714         struct uhci_hcd *uhci = hcd_to_uhci(hcd);
715         int rc = 0;
716
717         dev_dbg(uhci_dev(uhci), "%s\n", __FUNCTION__);
718
719         spin_lock_irq(&uhci->lock);
720         if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags) || uhci->dead)
721                 goto done_okay;         /* Already suspended or dead */
722
723         if (uhci->rh_state > UHCI_RH_SUSPENDED) {
724                 dev_warn(uhci_dev(uhci), "Root hub isn't suspended!\n");
725                 rc = -EBUSY;
726                 goto done;
727         };
728
729         /* All PCI host controllers are required to disable IRQ generation
730          * at the source, so we must turn off PIRQ.
731          */
732         pci_write_config_word(to_pci_dev(uhci_dev(uhci)), USBLEGSUP, 0);
733         mb();
734         hcd->poll_rh = 0;
735
736         /* FIXME: Enable non-PME# remote wakeup? */
737
738 done_okay:
739         clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
740 done:
741         spin_unlock_irq(&uhci->lock);
742         return rc;
743 }
744
745 static int uhci_resume(struct usb_hcd *hcd)
746 {
747         struct uhci_hcd *uhci = hcd_to_uhci(hcd);
748
749         dev_dbg(uhci_dev(uhci), "%s\n", __FUNCTION__);
750
751         /* Since we aren't in D3 any more, it's safe to set this flag
752          * even if the controller was dead.
753          */
754         set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
755         mb();
756
757         spin_lock_irq(&uhci->lock);
758
759         /* FIXME: Disable non-PME# remote wakeup? */
760
761         /* The firmware or a boot kernel may have changed the controller
762          * settings during a system wakeup.  Check it and reconfigure
763          * to avoid problems.
764          */
765         check_and_reset_hc(uhci);
766
767         /* If the controller was dead before, it's back alive now */
768         configure_hc(uhci);
769
770         if (uhci->rh_state == UHCI_RH_RESET) {
771
772                 /* The controller had to be reset */
773                 usb_root_hub_lost_power(hcd->self.root_hub);
774                 suspend_rh(uhci, UHCI_RH_SUSPENDED);
775         }
776
777         spin_unlock_irq(&uhci->lock);
778
779         if (!uhci->working_RD) {
780                 /* Suspended root hub needs to be polled */
781                 hcd->poll_rh = 1;
782                 usb_hcd_poll_rh_status(hcd);
783         }
784         return 0;
785 }
786 #endif
787
788 /* Wait until a particular device/endpoint's QH is idle, and free it */
789 static void uhci_hcd_endpoint_disable(struct usb_hcd *hcd,
790                 struct usb_host_endpoint *hep)
791 {
792         struct uhci_hcd *uhci = hcd_to_uhci(hcd);
793         struct uhci_qh *qh;
794
795         spin_lock_irq(&uhci->lock);
796         qh = (struct uhci_qh *) hep->hcpriv;
797         if (qh == NULL)
798                 goto done;
799
800         while (qh->state != QH_STATE_IDLE) {
801                 ++uhci->num_waiting;
802                 spin_unlock_irq(&uhci->lock);
803                 wait_event_interruptible(uhci->waitqh,
804                                 qh->state == QH_STATE_IDLE);
805                 spin_lock_irq(&uhci->lock);
806                 --uhci->num_waiting;
807         }
808
809         uhci_free_qh(uhci, qh);
810 done:
811         spin_unlock_irq(&uhci->lock);
812 }
813
814 static int uhci_hcd_get_frame_number(struct usb_hcd *hcd)
815 {
816         struct uhci_hcd *uhci = hcd_to_uhci(hcd);
817         unsigned frame_number;
818         unsigned delta;
819
820         /* Minimize latency by avoiding the spinlock */
821         frame_number = uhci->frame_number;
822         barrier();
823         delta = (inw(uhci->io_addr + USBFRNUM) - frame_number) &
824                         (UHCI_NUMFRAMES - 1);
825         return frame_number + delta;
826 }
827
828 static const char hcd_name[] = "uhci_hcd";
829
830 static const struct hc_driver uhci_driver = {
831         .description =          hcd_name,
832         .product_desc =         "UHCI Host Controller",
833         .hcd_priv_size =        sizeof(struct uhci_hcd),
834
835         /* Generic hardware linkage */
836         .irq =                  uhci_irq,
837         .flags =                HCD_USB11,
838
839         /* Basic lifecycle operations */
840         .reset =                uhci_init,
841         .start =                uhci_start,
842 #ifdef CONFIG_PM
843         .suspend =              uhci_suspend,
844         .resume =               uhci_resume,
845         .bus_suspend =          uhci_rh_suspend,
846         .bus_resume =           uhci_rh_resume,
847 #endif
848         .stop =                 uhci_stop,
849
850         .urb_enqueue =          uhci_urb_enqueue,
851         .urb_dequeue =          uhci_urb_dequeue,
852
853         .endpoint_disable =     uhci_hcd_endpoint_disable,
854         .get_frame_number =     uhci_hcd_get_frame_number,
855
856         .hub_status_data =      uhci_hub_status_data,
857         .hub_control =          uhci_hub_control,
858 };
859
860 static const struct pci_device_id uhci_pci_ids[] = { {
861         /* handle any USB UHCI controller */
862         PCI_DEVICE_CLASS(PCI_CLASS_SERIAL_USB_UHCI, ~0),
863         .driver_data =  (unsigned long) &uhci_driver,
864         }, { /* end: all zeroes */ }
865 };
866
867 MODULE_DEVICE_TABLE(pci, uhci_pci_ids);
868
869 static struct pci_driver uhci_pci_driver = {
870         .name =         (char *)hcd_name,
871         .id_table =     uhci_pci_ids,
872
873         .probe =        usb_hcd_pci_probe,
874         .remove =       usb_hcd_pci_remove,
875         .shutdown =     uhci_shutdown,
876
877 #ifdef  CONFIG_PM
878         .suspend =      usb_hcd_pci_suspend,
879         .resume =       usb_hcd_pci_resume,
880 #endif  /* PM */
881 };
882  
883 static int __init uhci_hcd_init(void)
884 {
885         int retval = -ENOMEM;
886
887         printk(KERN_INFO DRIVER_DESC " " DRIVER_VERSION "\n");
888
889         if (usb_disabled())
890                 return -ENODEV;
891
892         if (DEBUG_CONFIGURED) {
893                 errbuf = kmalloc(ERRBUF_LEN, GFP_KERNEL);
894                 if (!errbuf)
895                         goto errbuf_failed;
896                 uhci_debugfs_root = debugfs_create_dir("uhci", NULL);
897                 if (!uhci_debugfs_root)
898                         goto debug_failed;
899         }
900
901         uhci_up_cachep = kmem_cache_create("uhci_urb_priv",
902                 sizeof(struct urb_priv), 0, 0, NULL, NULL);
903         if (!uhci_up_cachep)
904                 goto up_failed;
905
906         retval = pci_register_driver(&uhci_pci_driver);
907         if (retval)
908                 goto init_failed;
909
910         return 0;
911
912 init_failed:
913         if (kmem_cache_destroy(uhci_up_cachep))
914                 warn("not all urb_privs were freed!");
915
916 up_failed:
917         debugfs_remove(uhci_debugfs_root);
918
919 debug_failed:
920         kfree(errbuf);
921
922 errbuf_failed:
923
924         return retval;
925 }
926
927 static void __exit uhci_hcd_cleanup(void) 
928 {
929         pci_unregister_driver(&uhci_pci_driver);
930         
931         if (kmem_cache_destroy(uhci_up_cachep))
932                 warn("not all urb_privs were freed!");
933
934         debugfs_remove(uhci_debugfs_root);
935         kfree(errbuf);
936 }
937
938 module_init(uhci_hcd_init);
939 module_exit(uhci_hcd_cleanup);
940
941 MODULE_AUTHOR(DRIVER_AUTHOR);
942 MODULE_DESCRIPTION(DRIVER_DESC);
943 MODULE_LICENSE("GPL");