From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bartlomiej Zolnierkiewicz Subject: [PATCH] amd74xx: workaround unreliable AltStatus register for nVidia controllers Date: Fri, 21 Nov 2008 22:38:50 +0100 Message-ID: <200811212238.51161.bzolnier@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Return-path: Received: from ey-out-2122.google.com ([74.125.78.26]:58041 "EHLO ey-out-2122.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752864AbYKUVoR (ORCPT ); Fri, 21 Nov 2008 16:44:17 -0500 Received: by ey-out-2122.google.com with SMTP id 6so478095eyi.37 for ; Fri, 21 Nov 2008 13:44:16 -0800 (PST) Content-Disposition: inline Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: linux-ide@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Remy LABENE , Borislav Petkov It seems that on some nVidia controllers using AltStatus register can be unreliable so default to Status register if the PCI device is in Compatibility Mode. In order to achieve this: * Add ide_pci_is_in_compatibility_mode() inline helper to . * Add IDE_HFLAG_BROKEN_ALTSTATUS host flag and set it in amd74xx host driver for nVidia controllers in Compatibility Mode. * Teach actual_try_to_identify() and drive_is_ready() about the new flag. This fixes the regression caused by removal of CONFIG_IDEPCI_SHARE_IRQ config option in 2.6.25 and using AltStatus register unconditionally when available (kernel.org bug #11659). [ Moreover for CONFIG_IDEPCI_SHARE_IRQ=y (which is what most distributions/people use) it never worked correctly. ] Thanks to Remy LABENE for help with debugging the problem. More info at: http://bugzilla.kernel.org/show_bug.cgi?id=11659 Reported-by: Remy LABENE Cc: Borislav Petkov Signed-off-by: Bartlomiej Zolnierkiewicz --- This fix should be safe for both .28 and -stable. drivers/ide/amd74xx.c | 11 ++++++++++- drivers/ide/ide-iops.c | 3 ++- drivers/ide/ide-probe.c | 3 ++- include/linux/ide.h | 8 ++++++++ 4 files changed, 22 insertions(+), 3 deletions(-) Index: b/drivers/ide/amd74xx.c =================================================================== --- a/drivers/ide/amd74xx.c +++ b/drivers/ide/amd74xx.c @@ -3,7 +3,7 @@ * IDE driver for Linux. * * Copyright (c) 2000-2002 Vojtech Pavlik - * Copyright (c) 2007 Bartlomiej Zolnierkiewicz + * Copyright (c) 2007-2008 Bartlomiej Zolnierkiewicz * * Based on the work of: * Andre Hedrick @@ -263,6 +263,15 @@ static int __devinit amd74xx_probe(struc d.udma_mask = ATA_UDMA5; } + /* + * It seems that on some nVidia controllers using AltStatus + * register can be unreliable so default to Status register + * if the device is in Compatibility Mode. + */ + if (dev->vendor == PCI_VENDOR_ID_NVIDIA && + ide_pci_is_in_compatibility_mode(dev)) + d.host_flags |= IDE_HFLAG_BROKEN_ALTSTATUS; + printk(KERN_INFO "%s %s: UDMA%s controller\n", d.name, pci_name(dev), amd_dma[fls(d.udma_mask) - 1]); Index: b/drivers/ide/ide-iops.c =================================================================== --- a/drivers/ide/ide-iops.c +++ b/drivers/ide/ide-iops.c @@ -468,7 +468,8 @@ int drive_is_ready (ide_drive_t *drive) * an interrupt with another pci card/device. We make no assumptions * about possible isa-pnp and pci-pnp issues yet. */ - if (hwif->io_ports.ctl_addr) + if (hwif->io_ports.ctl_addr && + (hwif->host_flags & IDE_HFLAG_BROKEN_ALTSTATUS) == 0) stat = hwif->tp_ops->read_altstatus(hwif); else /* Note: this may clear a pending IRQ!! */ Index: b/drivers/ide/ide-probe.c =================================================================== --- a/drivers/ide/ide-probe.c +++ b/drivers/ide/ide-probe.c @@ -266,7 +266,8 @@ static int actual_try_to_identify (ide_d /* take a deep breath */ msleep(50); - if (io_ports->ctl_addr) { + if (io_ports->ctl_addr && + (hwif->host_flags & IDE_HFLAG_BROKEN_ALTSTATUS) == 0) { a = tp_ops->read_altstatus(hwif); s = tp_ops->read_status(hwif); if ((a ^ s) & ~ATA_IDX) Index: b/include/linux/ide.h =================================================================== --- a/include/linux/ide.h +++ b/include/linux/ide.h @@ -1296,6 +1296,13 @@ extern int __ide_pci_register_driver(str #define ide_pci_register_driver(d) pci_register_driver(d) #endif +static inline int ide_pci_is_in_compatibility_mode(struct pci_dev *dev) +{ + if ((dev->class >> 8) == PCI_CLASS_STORAGE_IDE && (dev->class & 5) != 5) + return 1; + return 0; +} + void ide_pci_setup_ports(struct pci_dev *, const struct ide_port_info *, int, hw_regs_t *, hw_regs_t **); void ide_setup_pci_noise(struct pci_dev *, const struct ide_port_info *); @@ -1375,6 +1382,7 @@ enum { IDE_HFLAG_IO_32BIT = (1 << 24), /* unmask IRQs */ IDE_HFLAG_UNMASK_IRQS = (1 << 25), + IDE_HFLAG_BROKEN_ALTSTATUS = (1 << 26), /* serialize ports if DMA is possible (for sl82c105) */ IDE_HFLAG_SERIALIZE_DMA = (1 << 27), /* force host out of "simplex" mode */