| Message ID | 20170712050811.3620-1-dja@axtens.net |
|---|---|
| State | Superseded |
| Headers | show |
[+cc Catalin, Will, linux-arm-kernel] On Wed, Jul 12, 2017 at 03:08:11PM +1000, Daniel Axtens wrote: > The HiSilicon D05 board has some PCI bridges (PCI ID 19e5:1610) that > are not spec-compliant: the VGA Enable bit is hardwired to 0 and > writes do not change it. > > The HiSilicon engineers report that the bridge does not forward the > 0xa0000-0xbffff mem range and the 0x3b0-0x3bb and 0x3c0-0x3df I/O > ranges. > > Because the VGA Enable bit is hardwired to 0, the VGA arbiter refuses > to mark any card behind it as the boot device. This breaks Xorg > auto-detection. > > However, the hibmc VGA card (PCI ID 19e5:1711) has been tested and is > known to work when behind these bridges. (It does not require the > legacy resources to operate.) > > Provide a quirk so that this combination of bridge and card is eligible > to be the default VGA card. This fixes Xorg auto-detection on the D05. > > Cc: Xinliang Liu <z.liuxinliang@hisilicon.com> > Cc: Rongrong Zou <zourongrong@gmail.com> > Signed-off-by: Daniel Axtens <dja@axtens.net> > --- > > v3: fix commit message > v4: fix comment (forgot to git add/git commit, sorry for the noise) > > --- > drivers/pci/quirks.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 50 insertions(+) > > diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c > index 16e6cd86ad71..b42324cba29e 100644 > --- a/drivers/pci/quirks.c > +++ b/drivers/pci/quirks.c > @@ -25,6 +25,7 @@ > #include <linux/sched.h> > #include <linux/ktime.h> > #include <linux/mm.h> > +#include <linux/vgaarb.h> > #include <asm/dma.h> /* isa_dma_bridge_buggy */ > #include "pci.h" > > @@ -4664,3 +4665,52 @@ 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 HiSilicon D05 board has some PCI bridges (PCI ID 19e5:1610) > + * that are not spec-compliant: the VGA Enable bit is hardwired to 0 > + * and writes do not change it. The bridge does not forward legacy > + * memory or I/O resources. > + * > + * Because the VGA Enable bit is hardwired to 0, the VGA arbiter > + * refuses to mark any card behind it as the boot device. However, the > + * hibmc VGA card (PCI ID 19e5:1711) has been tested and is known to > + * work when behind these bridges. > + * > + * If we have this bridge, this card, and no default card already, > + * mark the card as default. > + */ > +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); Is this quirk useful on any arch other than arm64? Per drivers/pci/dwc/Kconfig, CONFIG_PCI_HISI depends on CONFIG_ARM64. Would it make sense to put this quirk in arch/arm64/kernel/pci.c?
Hi Bjorn, On Wed, Jul 12, 2017 at 03:04:30PM -0500, Bjorn Helgaas wrote: > [+cc Catalin, Will, linux-arm-kernel] > > On Wed, Jul 12, 2017 at 03:08:11PM +1000, Daniel Axtens wrote: > > The HiSilicon D05 board has some PCI bridges (PCI ID 19e5:1610) that > > are not spec-compliant: the VGA Enable bit is hardwired to 0 and > > writes do not change it. > > > > The HiSilicon engineers report that the bridge does not forward the > > 0xa0000-0xbffff mem range and the 0x3b0-0x3bb and 0x3c0-0x3df I/O > > ranges. > > > > Because the VGA Enable bit is hardwired to 0, the VGA arbiter refuses > > to mark any card behind it as the boot device. This breaks Xorg > > auto-detection. > > > > However, the hibmc VGA card (PCI ID 19e5:1711) has been tested and is > > known to work when behind these bridges. (It does not require the > > legacy resources to operate.) > > > > Provide a quirk so that this combination of bridge and card is eligible > > to be the default VGA card. This fixes Xorg auto-detection on the D05. > > > > Cc: Xinliang Liu <z.liuxinliang@hisilicon.com> > > Cc: Rongrong Zou <zourongrong@gmail.com> > > Signed-off-by: Daniel Axtens <dja@axtens.net> > > --- > > > > v3: fix commit message > > v4: fix comment (forgot to git add/git commit, sorry for the noise) > > > > --- > > drivers/pci/quirks.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++ > > 1 file changed, 50 insertions(+) > > > > diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c > > index 16e6cd86ad71..b42324cba29e 100644 > > --- a/drivers/pci/quirks.c > > +++ b/drivers/pci/quirks.c > > @@ -25,6 +25,7 @@ > > #include <linux/sched.h> > > #include <linux/ktime.h> > > #include <linux/mm.h> > > +#include <linux/vgaarb.h> > > #include <asm/dma.h> /* isa_dma_bridge_buggy */ > > #include "pci.h" > > > > @@ -4664,3 +4665,52 @@ 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 HiSilicon D05 board has some PCI bridges (PCI ID 19e5:1610) > > + * that are not spec-compliant: the VGA Enable bit is hardwired to 0 > > + * and writes do not change it. The bridge does not forward legacy > > + * memory or I/O resources. > > + * > > + * Because the VGA Enable bit is hardwired to 0, the VGA arbiter > > + * refuses to mark any card behind it as the boot device. However, the > > + * hibmc VGA card (PCI ID 19e5:1711) has been tested and is known to > > + * work when behind these bridges. > > + * > > + * If we have this bridge, this card, and no default card already, > > + * mark the card as default. > > + */ > > +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); > > Is this quirk useful on any arch other than arm64? Per > drivers/pci/dwc/Kconfig, CONFIG_PCI_HISI depends on CONFIG_ARM64. > > Would it make sense to put this quirk in arch/arm64/kernel/pci.c? We've resisted adding PCI quirks in the arch directory so far, so I'd rather it lived in the PCI code if you don't have a strong objection to that. Hardware vendors have a tendency to reuse broken IP, so it's not beyond the realms of imagination that this quirk might be needed for another part some day (e.g. based on 32-bit ARM). Will
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index 16e6cd86ad71..b42324cba29e 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -25,6 +25,7 @@ #include <linux/sched.h> #include <linux/ktime.h> #include <linux/mm.h> +#include <linux/vgaarb.h> #include <asm/dma.h> /* isa_dma_bridge_buggy */ #include "pci.h" @@ -4664,3 +4665,52 @@ 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 HiSilicon D05 board has some PCI bridges (PCI ID 19e5:1610) + * that are not spec-compliant: the VGA Enable bit is hardwired to 0 + * and writes do not change it. The bridge does not forward legacy + * memory or I/O resources. + * + * Because the VGA Enable bit is hardwired to 0, the VGA arbiter + * refuses to mark any card behind it as the boot device. However, the + * hibmc VGA card (PCI ID 19e5:1711) has been tested and is known to + * work when behind these bridges. + * + * If we have this bridge, this card, and no default card already, + * mark the card as default. + */ +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);
The HiSilicon D05 board has some PCI bridges (PCI ID 19e5:1610) that are not spec-compliant: the VGA Enable bit is hardwired to 0 and writes do not change it. The HiSilicon engineers report that the bridge does not forward the 0xa0000-0xbffff mem range and the 0x3b0-0x3bb and 0x3c0-0x3df I/O ranges. Because the VGA Enable bit is hardwired to 0, the VGA arbiter refuses to mark any card behind it as the boot device. This breaks Xorg auto-detection. However, the hibmc VGA card (PCI ID 19e5:1711) has been tested and is known to work when behind these bridges. (It does not require the legacy resources to operate.) Provide a quirk so that this combination of bridge and card is eligible to be the default VGA card. This fixes Xorg auto-detection on the D05. Cc: Xinliang Liu <z.liuxinliang@hisilicon.com> Cc: Rongrong Zou <zourongrong@gmail.com> Signed-off-by: Daniel Axtens <dja@axtens.net> --- v3: fix commit message v4: fix comment (forgot to git add/git commit, sorry for the noise) --- drivers/pci/quirks.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+)