Ray Lee wrote: > On Nov 7, 2007 10:34 AM, Roel Kluin <[EMAIL PROTECTED]> wrote: >> If count reaches zero, the loop ends, but the postfix decrement subtracts it. >> so, testing for 'count == 0' will not work. >> >> Signed-off-by: Roel Kluin <[EMAIL PROTECTED]> >> --- >> diff --git a/sound/oss/trident.c b/sound/oss/trident.c >> index 96adc47..94b5fb4 100644 >> --- a/sound/oss/trident.c >> +++ b/sound/oss/trident.c >> @@ -2939,7 +2939,7 @@ trident_ac97_set(struct ac97_codec *codec, u8 reg, u16 >> val) >> >> data |= (mask | (reg & AC97_REG_ADDR)); >> >> - if (count == 0) { >> + if (count == -1) { >> printk(KERN_ERR "trident: AC97 CODEC write timed out.\n"); >> spin_unlock_irqrestore(&card->lock, flags); >> return; >> @@ -2999,7 +2999,7 @@ trident_ac97_get(struct ac97_codec *codec, u8 reg) >> } while (count--); >> spin_unlock_irqrestore(&card->lock, flags); >> >> - if (count == 0) { >> + if (count == -1) { >> printk(KERN_ERR "trident: AC97 CODEC read timed out.\n"); >> data = 0; >> } > > You didn't test this: count is unsigned. Change the loop condition to > be --count instead. > > Ray
Yep, you're right, here: -- If count reaches zero, the loop ends, but the postfix decrement still subtracts: testing for 'count == 0' will not work. Signed-off-by: Roel Kluin <[EMAIL PROTECTED]> --- diff --git a/sound/oss/trident.c b/sound/oss/trident.c index 96adc47..6959ee1 100644 --- a/sound/oss/trident.c +++ b/sound/oss/trident.c @@ -2935,7 +2935,7 @@ trident_ac97_set(struct ac97_codec *codec, u8 reg, u16 val) do { if ((inw(TRID_REG(card, address)) & busy) == 0) break; - } while (count--); + } while (--count); data |= (mask | (reg & AC97_REG_ADDR)); @@ -2996,7 +2996,7 @@ trident_ac97_get(struct ac97_codec *codec, u8 reg) data = inl(TRID_REG(card, address)); if ((data & busy) == 0) break; - } while (count--); + } while (--count); spin_unlock_irqrestore(&card->lock, flags); if (count == 0) { - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/