From c3e59ee4e76686b0c84ca8faa1011d10cd4ca1b8 Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Thu, 15 Jan 2015 18:17:12 -0600 Subject: [PATCH] PCI: Mark Atheros AR93xx to avoid bus reset Reports against the TL-WDN4800 card indicate that PCI bus reset of this Atheros device cause system lock-ups and resets. I've also been able to confirm this behavior on multiple systems. The device never returns from reset and attempts to access config space of the device after reset result in hangs. Blacklist bus reset for the device to avoid this issue. [bhelgaas: This regression appeared in v3.14. Andreas bisected it to 425c1b223dac ("PCI: Add Virtual Channel to save/restore support"), but we don't understand the mechanism by which that commit affects the reset path.] [bhelgaas: changelog, references] Link: http://lkml.kernel.org/r/20140923210318.498dacbd@dualc.maya.org Reported-by: Andreas Hartmann Tested-by: Andreas Hartmann Signed-off-by: Alex Williamson Signed-off-by: Bjorn Helgaas CC: stable@vger.kernel.org # v3.14+ --- drivers/pci/quirks.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index ed6f89b6efe5..e52356aa09b8 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -3028,6 +3028,20 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_REALTEK, 0x8169, DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_MELLANOX, PCI_ANY_ID, quirk_broken_intx_masking); +static void quirk_no_bus_reset(struct pci_dev *dev) +{ + dev->dev_flags |= PCI_DEV_FLAGS_NO_BUS_RESET; +} + +/* + * Atheros AR93xx chips do not behave after a bus reset. The device will + * throw a Link Down error on AER-capable systems and regardless of AER, + * config space of the device is never accessible again and typically + * causes the system to hang or reset when access is attempted. + * http://www.spinics.net/lists/linux-pci/msg34797.html + */ +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATHEROS, 0x0030, quirk_no_bus_reset); + #ifdef CONFIG_ACPI /* * Apple: Shutdown Cactus Ridge Thunderbolt controller. -- 2.20.1