From 11f963511c5a94c5969fdbb5e6f4da2190592d6f Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 3 Jan 2004 02:25:13 -0800 Subject: [PATCH] Fix IDE "PIO WRITE wait for ready" test under extreme interrupt load. From Daniel Tram Lux: under extreme irq load on an underpowered CPU, the timeout loop may not make any progress, and decide that a timeout occurred before it has actually tested the status register. The minimal fix for now is to just have a final test _after_ the timeout to remove the problem. The real fix would likely be to not have irqs enabled between reading the status and the timeout. --- drivers/ide/ide-iops.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/ide/ide-iops.c b/drivers/ide/ide-iops.c index 06d6292cf70f3..a239bbaf5074d 100644 --- a/drivers/ide/ide-iops.c +++ b/drivers/ide/ide-iops.c @@ -647,6 +647,15 @@ int ide_wait_stat (ide_startstop_t *startstop, ide_drive_t *drive, u8 good, u8 b timeout += jiffies; while ((stat = hwif->INB(IDE_STATUS_REG)) & BUSY_STAT) { if (time_after(jiffies, timeout)) { + /* + * One last read after the timeout in case + * heavy interrupt load made us not make any + * progress during the timeout.. + */ + stat = hwif->INB(IDE_STATUS_REG); + if (!(stat & BUSY_STAT)) + break; + local_irq_restore(flags); *startstop = DRIVER(drive)->error(drive, "status timeout", stat); return 1; -- 2.53.0