Hi Bjorn,
On Thu, Sep 27, 2018 at 12:57 AM Bjorn Helgaas helgaas@kernel.org wrote:
[+cc Intel DRM maintainers, etc]
On Wed, Sep 26, 2018 at 08:14:01AM -0700, Bin Meng wrote:
Add more PCI IDs to the Intel GPU "spurious interrupt" quirk table, which are known to break.
Do you have a reference for this? Any public bug reports, bugzilla, Intel spec reference or errata? "Which are known to break" is pretty vague.
Sorry I used wrong words and should have been clearer. These devices are validated to be broken. The test I used is very simple, just unplug the VGA cable and plug it again, and "spurious interrupt" will be seen on the interrupt line of the IGD device. I was not aware of any public bugs filed to Intel, nor seen any errata from Intel.
See commit f67fd55fa96f ("PCI: Add quirk for still enabled interrupts on Intel Sandy Bridge GPUs"), and commit 7c82126a94e6 ("PCI: Add new ID for Intel GPU "spurious interrupt" quirk") for some history.
Based on current findings, it is highly possible that all Intel 1st/2nd/3rd generation Core processors' IGD has such quirk.
Can you include a reference to these "current findings"? I assume you have bug reports that include the device IDs you're adding? If not, how did you build this list of new IDs?
By "current findings" I mean given the IDs we have here, plus previous one added by Thomas, it's highly possible this VGA BIOS bug exists in every 1st/2nd/3rd generation Core processors.
The function comment added by f67fd55fa96f ("PCI: Add quirk for still enabled interrupts on Intel Sandy Bridge GPUs") suggests that this is actually a BIOS issue, not a hardware erratum, i.e., I don't see anything there that suggests a hardware defect.
But there must be a hole somewhere -- the kernel can't be expected to disable interrupts in device-specific ways when there's no driver loaded. Maybe it's simply a BIOS defect or maybe there's some interrupt or _PRT-related setup we're missing.
It's a pure VGA BIOS bug, not the BIOS bug or _PRT etc. The VGA BIOS forgot to turn off the interrupt on these devices.
Signed-off-by: Bin Meng bmeng.cn@gmail.com Cc: stable@vger.kernel.org # v3.4+
drivers/pci/quirks.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index 6bc27b7..c0673a7 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -3190,7 +3190,11 @@ static void disable_igfx_irq(struct pci_dev *dev)
pci_iounmap(dev, regs);} +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x0042, disable_igfx_irq); +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x0046, disable_igfx_irq); +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x004a, disable_igfx_irq); DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x0102, disable_igfx_irq); +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x0106, disable_igfx_irq); DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x010a, disable_igfx_irq); DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x0152, disable_igfx_irq);
--
Regards, Bin