vt6421 has problems talking to recent WD drives. It causes a lot of transmission errors while high bandwidth transfer as reported in the following bugzilla entry. https://bugzilla.kernel.org/show_bug.cgi?id=15173 Joseph Chan provided the following fix. I don't have any idea what it does but I can verify the issue is gone with the patch applied. Signed-off-by: Tejun Heo <tj@xxxxxxxxxx> Originally-from: Joseph Chan <JosephChan@xxxxxxxxxx> Reported-by: Jorrit Tijben <sjorrit@xxxxxxxxx> Cc: stable@xxxxxxxxxx --- Joseph, can you please add some documentation of what it does and why? Thanks. drivers/ata/sata_via.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/ata/sata_via.c b/drivers/ata/sata_via.c index 101d8c2..0ecd0f6 100644 --- a/drivers/ata/sata_via.c +++ b/drivers/ata/sata_via.c @@ -575,6 +575,19 @@ static void svia_configure(struct pci_dev *pdev) tmp8 |= NATIVE_MODE_ALL; pci_write_config_byte(pdev, SATA_NATIVE_MODE, tmp8); } + + /* + * vt6421 has problems talking to some drives. The following + * is the magic fix from Joseph Chan <JosephChan@xxxxxxxxxx>. + * Please add proper documentation if possible. + * + * https://bugzilla.kernel.org/show_bug.cgi?id=15173 + */ + if (pdev->device == 0x3249) { + pci_read_config_byte(pdev, 0x52, &tmp8); + tmp8 |= 1 << 2; + pci_write_config_byte(pdev, 0x52, tmp8); + } } static int svia_init_one(struct pci_dev *pdev, const struct pci_device_id *ent) -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html