[PATCH 5.10 291/406] Revert "PCI: Mark NVIDIA T4 GPUs to avoid bus reset"

Greg Kroah-Hartman
2023-09-17T19:37:00Z

From: Bjorn Helgaas <bhelgaas@google.com>

commit 5260bd6d36c83c5b269c33baaaf8c78e520908b0 upstream.

This reverts commit d5af729dc2071273f14cbb94abbc60608142fd83.

d5af729dc207 ("PCI: Mark NVIDIA T4 GPUs to avoid bus reset") avoided
Secondary Bus Reset on the T4 because the reset seemed to not work when the
T4 was directly attached to a Root Port.

But NVIDIA thinks the issue is probably related to some issue with the Root
Port, not with the T4. The T4 provides neither PM nor FLR reset, so
masking bus reset compromises this device for assignment scenarios.

Revert d5af729dc207 as requested by Wu Zongyong. This will leave SBR
broken in the specific configuration Wu tested, as it was in v6.5, so Wu
will debug that further.

Link: https://lore.kernel.org/r/ZPqMCDWvITlOLHgJ@wuzongyong-alibaba
Link: https://lore.kernel.org/r/20230908201104.GA305023@bhelgaas
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/pci/quirks.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -3578,7 +3578,7 @@ static void quirk_no_bus_reset(struct pc
*/
static void quirk_nvidia_no_bus_reset(struct pci_dev *dev)
{
- if ((dev->device & 0xffc0) == 0x2340 || dev->device == 0x1eb8)
+ if ((dev->device & 0xffc0) == 0x2340)
quirk_no_bus_reset(dev);
}
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_NVIDIA, PCI_ANY_ID,