From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f66.google.com ([74.125.83.66]:35723 "EHLO mail-pg0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753227AbdFSCgQ (ORCPT ); Sun, 18 Jun 2017 22:36:16 -0400 Received: by mail-pg0-f66.google.com with SMTP id f127so13743347pgc.2 for ; Sun, 18 Jun 2017 19:36:16 -0700 (PDT) From: Daniel Axtens To: linux-pci@vger.kernel.org Cc: Daniel Axtens , Xinliang Liu , Rongrong Zou Subject: [PATCH] PCI: Support hibmc VGA cards behind a misbehaving HiSilicon bridge Date: Mon, 19 Jun 2017 12:35:28 +1000 Message-Id: <20170619023528.11532-1-dja@axtens.net> Sender: linux-pci-owner@vger.kernel.org List-ID: The HiSilicon D05 board has some PCI bridges (PCI ID 19e5:1610) that are not spec-compliant: they do not set the VGA Enable bit when a VGA card is behind the bridge. This breaks Xorg auto-detection. Despite this, the hibmc VGA card (PCI ID 19e5:1711) is known to work when behind these bridges. Provide a quirk so that this combination of bridge and card is eligible to be the default VGA card. This fixes Xorg auto-detection. Cc: Xinliang Liu Cc: Rongrong Zou Signed-off-by: Daniel Axtens --- drivers/pci/quirks.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+) diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index 16e6cd86ad71..9475d6056dd3 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -25,6 +25,7 @@ #include #include #include +#include #include /* isa_dma_bridge_buggy */ #include "pci.h" @@ -4664,3 +4665,48 @@ static void quirk_intel_no_flr(struct pci_dev *dev) } DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x1502, quirk_intel_no_flr); DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x1503, quirk_intel_no_flr); + +/* + * The hibmc card on a HiSilicon D05 board sits behind a non-compliant + * bridge. The bridge doesn't advertise the PCI_BRIDGE_CTL_VGA bit in + * its config space. This prevents the vgaarb from marking a card + * behind it as boot VGA device. + * + * However, the hibmc card is known to still work, so if we have that + * card behind that particular bridge (19e5:1610), mark it as the + * default device if none has been detected. + */ +static void hibmc_fixup_vgaarb(struct pci_dev *pdev) +{ + struct pci_dev *bridge; + struct pci_bus *bus; + u16 config; + + bus = pdev->bus; + bridge = bus->self; + if (!bridge) + return; + + if (!pci_is_bridge(bridge)) + return; + + if (bridge->vendor != PCI_VENDOR_ID_HUAWEI || + bridge->device != 0x1610) + return; + + pci_read_config_word(bridge, PCI_BRIDGE_CONTROL, + &config); + if (config & PCI_BRIDGE_CTL_VGA) { + /* + * Weirdly, this bridge *is* spec compliant, so bail + * and let vgaarb do its job + */ + return; + } + + if (vga_default_device()) + return; + + vga_set_default_device(pdev); +} +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_HUAWEI, 0x1711, hibmc_fixup_vgaarb); -- 2.11.0