From 8b27ff4cf6d15964aa2987aeb58db4dfb1f87a19 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Mon, 31 May 2010 16:26:48 +0200 Subject: [PATCH] sata_via: magic vt6421 fix for transmission problems w/ WD drives 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 Originally-from: Joseph Chan Reported-by: Jorrit Tijben Cc: stable@kernel.org Signed-off-by: Jeff Garzik --- 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 101d8c219caf..0ecd0f6aa2c0 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 . + * 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)