From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Garrett Subject: [PATCH] Clear abnormal poweroff flag on VIA southbridges, fix resume Date: Sun, 18 Jun 2006 20:14:22 +0100 Message-ID: <20060618191421.GA15358@srcf.ucam.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from cavan.codon.org.uk ([217.147.92.49]:55704 "EHLO vavatch.codon.org.uk") by vger.kernel.org with ESMTP id S932288AbWFRTOZ (ORCPT ); Sun, 18 Jun 2006 15:14:25 -0400 Content-Disposition: inline Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org Some VIA southbridges contain a flag in the ACPI register space that indicates whether an abnormal poweroff has occured, presumably with the intention that it can be cleared on clean shutdown. Some BIOSes check this flag at resume time, and will re-POST the system rather than jump back to the OS if it's set. Clearing it at boot time appears to be sufficient. I'm not sure if drivers/pci/quirks.c is the right place to do it, but I'm not sure where would be cleaner. Signed-off-by: Matthew Garrett diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index 7537260..2f9f996 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -660,6 +660,33 @@ static void __devinit quirk_vt82c598_id( } DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C597_0, quirk_vt82c598_id ); +#ifdef CONFIG_ACPI + +/* Some VIA systems boot with the abnormal status flag set. This can cause + * the BIOS to re-POST the system on resume rather than passing control + * back to the OS. Clear the flag on boot + */ + +static void __devinit quirk_via_abnormal_poweroff(struct pci_dev *dev) +{ + u32 register; + + acpi_hw_register_read (ACPI_MTX_DO_NOT_LOCK, ACPI_REGISTER_PM1_STATUS, + ®ister); + + if (register & 0x800) { + printk ("Clearing abnormal poweroff flag\n"); + acpi_hw_register_write (ACPI_MTX_DO_NOT_LOCK, + ACPI_REGISTER_PM1_STATUS, + (u16)0x800); + } +} + +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_VIA, PCI_DEVICE_ID_VIA_8235, quirk_via_abnormal_poweroff); +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_VIA, PCI_DEVICE_ID_VIA_8237, quirk_via_abnormal_poweroff); + +#endif + /* * CardBus controllers have a legacy base address that enables them * to respond as i82365 pcmcia controllers. We don't want them to -- Matthew Garrett | mjg59@srcf.ucam.org