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| author | Alan Cox | 2007-04-23 12:55:36 +0200 |
|---|---|---|
| committer | Jeff Garzik | 2007-04-28 20:51:33 +0200 |
| commit | 4f701d1e9a796a3d6657e1129bee0566d7cda916 (patch) | |
| tree | ac2b13b4fc37bcc29ada2f46fde1e2cd2d734052 /drivers/ata/libata-core.c | |
| parent | libata: add missing call to ->cable_detect() in new EH path (diff) | |
| download | kernel-qcow2-linux-4f701d1e9a796a3d6657e1129bee0566d7cda916.tar.gz kernel-qcow2-linux-4f701d1e9a796a3d6657e1129bee0566d7cda916.tar.xz kernel-qcow2-linux-4f701d1e9a796a3d6657e1129bee0566d7cda916.zip | |
ata_timing: ensure t->cycle is always correct
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@redhat.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Diffstat (limited to 'drivers/ata/libata-core.c')
| -rw-r--r-- | drivers/ata/libata-core.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index 227399e48470..4e1df5382b9a 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -2639,6 +2639,12 @@ int ata_timing_compute(struct ata_device *adev, unsigned short speed, t->active += (t->cycle - (t->active + t->recover)) / 2; 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; } |