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authorTejun Heo <htejun@gmail.com>2006-11-11 20:10:45 +0900
committerJeff Garzik <jeff@garzik.org>2006-12-01 22:45:54 -0500
commit6fc49adb9417b9c793e8f88d485387bb89ceb733 (patch)
treed94f536f24e504b1a654c392171fb6f08a195ca2 /include
parent648a88be4a016d2637ace3ae74b85a0512255ee8 (diff)
[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 'include')
-rw-r--r--include/linux/libata.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 0d0ddeaee73..36e233cc388 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -140,6 +140,7 @@ enum {
ATA_DFLAG_LBA48 = (1 << 1), /* device supports LBA48 */
ATA_DFLAG_CDB_INTR = (1 << 2), /* device asserts INTRQ when ready for CDB */
ATA_DFLAG_NCQ = (1 << 3), /* device supports NCQ */
+ ATA_DFLAG_FLUSH_EXT = (1 << 4), /* do FLUSH_EXT instead of FLUSH */
ATA_DFLAG_CFG_MASK = (1 << 8) - 1,
ATA_DFLAG_PIO = (1 << 8), /* device limited to PIO mode */