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author | Tejun Heo <htejun@gmail.com> | 2006-11-11 20:10:45 +0900 |
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committer | Jeff Garzik <jeff@garzik.org> | 2006-12-01 22:45:54 -0500 |
commit | 6fc49adb9417b9c793e8f88d485387bb89ceb733 (patch) | |
tree | d94f536f24e504b1a654c392171fb6f08a195ca2 /drivers/ata/libata-core.c | |
parent | 648a88be4a016d2637ace3ae74b85a0512255ee8 (diff) | |
download | linux-6fc49adb9417b9c793e8f88d485387bb89ceb733.tar.gz linux-6fc49adb9417b9c793e8f88d485387bb89ceb733.tar.bz2 linux-6fc49adb9417b9c793e8f88d485387bb89ceb733.zip |
[PATCH] libata: use FLUSH_EXT only when driver is larger than LBA28 limit
Many drives support LBA48 even when its capacity is smaller than
1<<28, as LBA48 is required for many functionalities. FLUSH_EXT is
mandatory for drives w/ LBA48 support.
Interestingly, at least one of such drives (ST960812A) has problems
dealing with FLUSH_EXT. It eventually completes the command but takes
around 7 seconds to finish in many cases thus drastically slowing down
IO transactions. This seems to be a firmware bug which sneaked into
production probably because no other ATA driver including linux IDE
issues FLUSH_EXT to drives which report support for LBA48 & FLUSH_EXT
but is smaller than 1<<28 blocks.
This patch adds ATA_DFLAG_FLUSH_EXT which is set iff the drive
supports LBA48 & FLUSH_EXT and is larger than LBA28 limit. Both cache
flush paths are updated to issue FLUSH_EXT only when the flag is set.
Note that the changed behavior is more inline with the rest of libata.
libata prefers shorter commands whenever possible.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Danny Kukawka <dkukawka@novell.com>
Cc: Stefan Seyfried <seife@novell.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, 5 insertions, 1 deletions
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index f531a89c26c9..d94b8a02c340 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -1457,6 +1457,10 @@ int ata_dev_configure(struct ata_device *dev) if (ata_id_has_lba48(id)) { dev->flags |= ATA_DFLAG_LBA48; lba_desc = "LBA48"; + + if (dev->n_sectors >= (1UL << 28) && + ata_id_has_flush_ext(id)) + dev->flags |= ATA_DFLAG_FLUSH_EXT; } /* config NCQ */ @@ -5128,7 +5132,7 @@ int ata_flush_cache(struct ata_device *dev) if (!ata_try_flush_cache(dev)) return 0; - if (ata_id_has_flush_ext(dev->id)) + if (dev->flags & ATA_DFLAG_FLUSH_EXT) cmd = ATA_CMD_FLUSH_EXT; else cmd = ATA_CMD_FLUSH; |