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| author | Mark Lord <liml@rtr.ca> | 2009-04-13 17:29:34 +0200 |
|---|---|---|
| committer | Jeff Garzik <jgarzik@redhat.com> | 2009-04-18 01:04:28 +0200 |
| commit | 299b3f8df90a3f7416d8df121d8a42b1a2aeced4 (patch) | |
| tree | 600bd461c66e9980c3dc3554148fb594e5805f5f /drivers/ata | |
| parent | sata_mv: tidy up qc->tf usage in qc_prep() functions (diff) | |
| download | linux-299b3f8df90a3f7416d8df121d8a42b1a2aeced4.tar.xz linux-299b3f8df90a3f7416d8df121d8a42b1a2aeced4.zip | |
sata_mv: workaround for multi_count errata sata24
Workaround for errata SATA#24 in sata_mv.
This errata affects WRITE_MULTI* commands when
the device multi_count produces a DRQ block size >= 4Kbytes.
We work around it here by converting such operations
into ordinary PIO_WRITEs instead.
Note that this might result in a PIO FUA write unavoidably being converted
into a non-FUA write. In practice, any system using FUA is also going to be
using DMA rather than PIO, so this shouldn't affect anyone in the real world.
Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Diffstat (limited to 'drivers/ata')
| -rw-r--r-- | drivers/ata/sata_mv.c | 44 |
1 files changed, 42 insertions, 2 deletions
diff --git a/drivers/ata/sata_mv.c b/drivers/ata/sata_mv.c index c7da6022c6b4..870dcfd82357 100644 --- a/drivers/ata/sata_mv.c +++ b/drivers/ata/sata_mv.c @@ -1881,6 +1881,39 @@ static u8 mv_bmdma_status(struct ata_port *ap) return status; } +static void mv_rw_multi_errata_sata24(struct ata_queued_cmd *qc) +{ + struct ata_taskfile *tf = &qc->tf; + /* + * Workaround for 88SX60x1 FEr SATA#24. + * + * Chip may corrupt WRITEs if multi_count >= 4kB. + * Note that READs are unaffected. + * + * It's not clear if this errata really means "4K bytes", + * or if it always happens for multi_count > 7 + * regardless of device sector_size. + * + * So, for safety, any write with multi_count > 7 + * gets converted here into a regular PIO write instead: + */ + if ((tf->flags & ATA_TFLAG_WRITE) && is_multi_taskfile(tf)) { + if (qc->dev->multi_count > 7) { + switch (tf->command) { + case ATA_CMD_WRITE_MULTI: + tf->command = ATA_CMD_PIO_WRITE; + break; + case ATA_CMD_WRITE_MULTI_FUA_EXT: + tf->flags &= ~ATA_TFLAG_FUA; /* ugh */ + /* fall through */ + case ATA_CMD_WRITE_MULTI_EXT: + tf->command = ATA_CMD_PIO_WRITE_EXT; + break; + } + } + } +} + /** * mv_qc_prep - Host specific command preparation. * @qc: queued command to prepare @@ -1902,9 +1935,16 @@ static void mv_qc_prep(struct ata_queued_cmd *qc) u16 flags = 0; unsigned in_index; - if ((tf->protocol != ATA_PROT_DMA) && - (tf->protocol != ATA_PROT_NCQ)) + switch (tf->protocol) { + case ATA_PROT_DMA: + case ATA_PROT_NCQ: + break; /* continue below */ + case ATA_PROT_PIO: + mv_rw_multi_errata_sata24(qc); return; + default: + return; + } /* Fill in command request block */ |