From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: [PATCH #upstream-fixes] sata_via: magic vt6421 fix for transmission problems w/ WD drives Date: Mon, 31 May 2010 16:26:48 +0200 Message-ID: <4C03C728.9080107@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from hera.kernel.org ([140.211.167.34]:44698 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755158Ab0EaO1A (ORCPT ); Mon, 31 May 2010 10:27:00 -0400 Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Jeff Garzik , "linux-ide@vger.kernel.org" , JosephChan@via.com.tw Cc: sjorrit@gmail.com, stable@kernel.org 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 --- 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 . + * 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)