From 6fc49adb9417b9c793e8f88d485387bb89ceb733 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Sat, 11 Nov 2006 20:10:45 +0900 Subject: [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 Cc: Danny Kukawka Cc: Stefan Seyfried Signed-off-by: Jeff Garzik --- drivers/ata/libata-core.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'drivers/ata/libata-core.c') diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index f531a89c26c..d94b8a02c34 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; -- cgit v1.2.2