From: Alan Cox <alan@xxxxxxxxxxxxxxxxxxx> Russell King hit a case where quantisation errors accumulated such that the cycle time was shorter than rather than equal to the active/recovery time. The code already knows how to stretch times to fit the cycle time but does not know about the reverse. Signed-off-by: Alan Cox <alan@xxxxxxxxxx> Cc: Tejun Heo <htejun@xxxxxxxxx> Cc: Jeff Garzik <jeff@xxxxxxxxxx> Cc: Russell King <rmk@xxxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- drivers/ata/libata-core.c | 6 ++++++ 1 file changed, 6 insertions(+) diff -puN drivers/ata/libata-core.c~ata_timing-ensure-t-cycle-is-always-correct drivers/ata/libata-core.c --- a/drivers/ata/libata-core.c~ata_timing-ensure-t-cycle-is-always-correct +++ a/drivers/ata/libata-core.c @@ -2618,6 +2618,12 @@ int ata_timing_compute(struct ata_device t->recover = t->cycle - t->active; } + /* In a few cases quantisation may produce enough errors to + leave t->cycle too low for the sum of active and recovery + if so we must correct this */ + if (t->active + t->recover > t->cycle) + t->cycle = t->active + t->recover; + return 0; } _ - To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
