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authorDavid Brownell <david-b@pacbell.net>2007-04-02 02:49:47 -0400
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-04-02 13:06:09 -0400
commitbcd9b89c02295b075fda4bdb666f6641f8212226 (patch)
treeb566062a9754fb8fb5a47975312da89b0798dddc
parenta2b091dbfb355d0cd35756c6ace0988c9855f3f7 (diff)
[PATCH] rtc-cmos lockdep fix, irq updates
Lockdep reported cmos_suspend() and cmos_resume() calling rtc_update_irq() with IRQs enabled; not allowed. Also fix problems seen on some hardware, whereby false alarm IRQs could be reported (primarily to userspace); and update two comments to match changes in ACPI. Those make up most of this patch, by volume. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Cc: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--drivers/rtc/rtc-cmos.c50
1 files changed, 33 insertions, 17 deletions
diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c
index 85bf795abdcc..7c0d60910077 100644
--- a/drivers/rtc/rtc-cmos.c
+++ b/drivers/rtc/rtc-cmos.c
@@ -59,6 +59,19 @@ struct cmos_rtc {
59 59
60static const char driver_name[] = "rtc_cmos"; 60static const char driver_name[] = "rtc_cmos";
61 61
62/* The RTC_INTR register may have e.g. RTC_PF set even if RTC_PIE is clear;
63 * always mask it against the irq enable bits in RTC_CONTROL. Bit values
64 * are the same: PF==PIE, AF=AIE, UF=UIE; so RTC_IRQMASK works with both.
65 */
66#define RTC_IRQMASK (RTC_PF | RTC_AF | RTC_UF)
67
68static inline int is_intr(u8 rtc_intr)
69{
70 if (!(rtc_intr & RTC_IRQF))
71 return 0;
72 return rtc_intr & RTC_IRQMASK;
73}
74
62/*----------------------------------------------------------------*/ 75/*----------------------------------------------------------------*/
63 76
64static int cmos_read_time(struct device *dev, struct rtc_time *t) 77static int cmos_read_time(struct device *dev, struct rtc_time *t)
@@ -188,7 +201,8 @@ static int cmos_set_alarm(struct device *dev, struct rtc_wkalrm *t)
188 rtc_control &= ~RTC_AIE; 201 rtc_control &= ~RTC_AIE;
189 CMOS_WRITE(rtc_control, RTC_CONTROL); 202 CMOS_WRITE(rtc_control, RTC_CONTROL);
190 rtc_intr = CMOS_READ(RTC_INTR_FLAGS); 203 rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
191 if (rtc_intr) 204 rtc_intr &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;
205 if (is_intr(rtc_intr))
192 rtc_update_irq(&cmos->rtc->class_dev, 1, rtc_intr); 206 rtc_update_irq(&cmos->rtc->class_dev, 1, rtc_intr);
193 207
194 /* update alarm */ 208 /* update alarm */
@@ -207,7 +221,8 @@ static int cmos_set_alarm(struct device *dev, struct rtc_wkalrm *t)
207 rtc_control |= RTC_AIE; 221 rtc_control |= RTC_AIE;
208 CMOS_WRITE(rtc_control, RTC_CONTROL); 222 CMOS_WRITE(rtc_control, RTC_CONTROL);
209 rtc_intr = CMOS_READ(RTC_INTR_FLAGS); 223 rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
210 if (rtc_intr) 224 rtc_intr &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;
225 if (is_intr(rtc_intr))
211 rtc_update_irq(&cmos->rtc->class_dev, 1, rtc_intr); 226 rtc_update_irq(&cmos->rtc->class_dev, 1, rtc_intr);
212 } 227 }
213 228
@@ -287,7 +302,8 @@ cmos_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
287 } 302 }
288 CMOS_WRITE(rtc_control, RTC_CONTROL); 303 CMOS_WRITE(rtc_control, RTC_CONTROL);
289 rtc_intr = CMOS_READ(RTC_INTR_FLAGS); 304 rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
290 if (rtc_intr) 305 rtc_intr &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;
306 if (is_intr(rtc_intr))
291 rtc_update_irq(&cmos->rtc->class_dev, 1, rtc_intr); 307 rtc_update_irq(&cmos->rtc->class_dev, 1, rtc_intr);
292 spin_unlock_irqrestore(&rtc_lock, flags); 308 spin_unlock_irqrestore(&rtc_lock, flags);
293 return 0; 309 return 0;
@@ -353,12 +369,10 @@ static irqreturn_t cmos_interrupt(int irq, void *p)
353 369
354 spin_lock(&rtc_lock); 370 spin_lock(&rtc_lock);
355 irqstat = CMOS_READ(RTC_INTR_FLAGS); 371 irqstat = CMOS_READ(RTC_INTR_FLAGS);
372 irqstat &= (CMOS_READ(RTC_CONTROL) & RTC_IRQMASK) | RTC_IRQF;
356 spin_unlock(&rtc_lock); 373 spin_unlock(&rtc_lock);
357 374
358 if (irqstat) { 375 if (is_intr(irqstat)) {
359 /* NOTE: irqstat may have e.g. RTC_PF set
360 * even when RTC_PIE is clear...
361 */
362 rtc_update_irq(p, 1, irqstat); 376 rtc_update_irq(p, 1, irqstat);
363 return IRQ_HANDLED; 377 return IRQ_HANDLED;
364 } else 378 } else
@@ -525,25 +539,26 @@ static int cmos_suspend(struct device *dev, pm_message_t mesg)
525{ 539{
526 struct cmos_rtc *cmos = dev_get_drvdata(dev); 540 struct cmos_rtc *cmos = dev_get_drvdata(dev);
527 int do_wake = device_may_wakeup(dev); 541 int do_wake = device_may_wakeup(dev);
528 unsigned char tmp, irqstat; 542 unsigned char tmp;
529 543
530 /* only the alarm might be a wakeup event source */ 544 /* only the alarm might be a wakeup event source */
531 spin_lock_irq(&rtc_lock); 545 spin_lock_irq(&rtc_lock);
532 cmos->suspend_ctrl = tmp = CMOS_READ(RTC_CONTROL); 546 cmos->suspend_ctrl = tmp = CMOS_READ(RTC_CONTROL);
533 if (tmp & (RTC_PIE|RTC_AIE|RTC_UIE)) { 547 if (tmp & (RTC_PIE|RTC_AIE|RTC_UIE)) {
548 unsigned char irqstat;
549
534 if (do_wake) 550 if (do_wake)
535 tmp &= ~(RTC_PIE|RTC_UIE); 551 tmp &= ~(RTC_PIE|RTC_UIE);
536 else 552 else
537 tmp &= ~(RTC_PIE|RTC_AIE|RTC_UIE); 553 tmp &= ~(RTC_PIE|RTC_AIE|RTC_UIE);
538 CMOS_WRITE(tmp, RTC_CONTROL); 554 CMOS_WRITE(tmp, RTC_CONTROL);
539 irqstat = CMOS_READ(RTC_INTR_FLAGS); 555 irqstat = CMOS_READ(RTC_INTR_FLAGS);
540 } else 556 irqstat &= (tmp & RTC_IRQMASK) | RTC_IRQF;
541 irqstat = 0; 557 if (is_intr(irqstat))
558 rtc_update_irq(&cmos->rtc->class_dev, 1, irqstat);
559 }
542 spin_unlock_irq(&rtc_lock); 560 spin_unlock_irq(&rtc_lock);
543 561
544 if (irqstat)
545 rtc_update_irq(&cmos->rtc->class_dev, 1, irqstat);
546
547 /* ACPI HOOK: enable ACPI_EVENT_RTC when (tmp & RTC_AIE) 562 /* ACPI HOOK: enable ACPI_EVENT_RTC when (tmp & RTC_AIE)
548 * ... it'd be best if we could do that under rtc_lock. 563 * ... it'd be best if we could do that under rtc_lock.
549 */ 564 */
@@ -573,9 +588,10 @@ static int cmos_resume(struct device *dev)
573 spin_lock_irq(&rtc_lock); 588 spin_lock_irq(&rtc_lock);
574 CMOS_WRITE(tmp, RTC_CONTROL); 589 CMOS_WRITE(tmp, RTC_CONTROL);
575 tmp = CMOS_READ(RTC_INTR_FLAGS); 590 tmp = CMOS_READ(RTC_INTR_FLAGS);
576 spin_unlock_irq(&rtc_lock); 591 tmp &= (cmos->suspend_ctrl & RTC_IRQMASK) | RTC_IRQF;
577 if (tmp) 592 if (is_intr(tmp))
578 rtc_update_irq(&cmos->rtc->class_dev, 1, tmp); 593 rtc_update_irq(&cmos->rtc->class_dev, 1, tmp);
594 spin_unlock_irq(&rtc_lock);
579 } 595 }
580 596
581 pr_debug("%s: resume, ctrl %02x\n", 597 pr_debug("%s: resume, ctrl %02x\n",
@@ -594,7 +610,7 @@ static int cmos_resume(struct device *dev)
594/*----------------------------------------------------------------*/ 610/*----------------------------------------------------------------*/
595 611
596/* The "CMOS" RTC normally lives on the platform_bus. On ACPI systems, 612/* The "CMOS" RTC normally lives on the platform_bus. On ACPI systems,
597 * the device node may alternatively be created as a PNP device. 613 * the device node will always be created as a PNPACPI device.
598 */ 614 */
599 615
600#ifdef CONFIG_PNPACPI 616#ifdef CONFIG_PNPACPI
@@ -673,7 +689,7 @@ module_exit(cmos_exit);
673/*----------------------------------------------------------------*/ 689/*----------------------------------------------------------------*/
674 690
675/* Platform setup should have set up an RTC device, when PNPACPI is 691/* Platform setup should have set up an RTC device, when PNPACPI is
676 * unavailable ... this is the normal case, common even on PCs. 692 * unavailable ... this could happen even on (older) PCs.
677 */ 693 */
678 694
679static int __init cmos_platform_probe(struct platform_device *pdev) 695static int __init cmos_platform_probe(struct platform_device *pdev)