From: Johnny-CC Chang <Johnny-CC.Chang@mediatek.com>

Nvidia GB10 PCIe hosts will encounter problem occasionally
after SBR(secondary bus reset) is applied.
Enable NO_BUS_RESET quirk for Nvidia GB10 PCIe hosts.

Signed-off-by: Johnny-CC Chang <Johnny-CC.Chang@mediatek.com>
---
 drivers/pci/quirks.c    | 11 +++++++++++
 include/linux/pci_ids.h |  2 ++
 2 files changed, 13 insertions(+)

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index b94264cd3833..12a10fa84c8a 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -3746,6 +3746,17 @@ static void quirk_no_bus_reset(struct pci_dev *dev)
 	dev->dev_flags |= PCI_DEV_FLAGS_NO_BUS_RESET;
 }
 
+/*
+ * Nvidia GB10 PCIe hosts will encounter problem occasionally
+ * after SBR (secondary bus reset) is applied.
+ * SBR needs to be prevented for these PCIe hosts.
+ */
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_GB10_GEN5_X4,
+			 quirk_no_bus_reset);
+
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_GB10_GEN4_X1,
+			 quirk_no_bus_reset);
+
 /*
  * Some NVIDIA GPU devices do not work with bus reset, SBR needs to be
  * prevented for those affected devices.
diff --git a/include/linux/pci_ids.h b/include/linux/pci_ids.h
index 92ffc4373f6d..661dc1594213 100644
--- a/include/linux/pci_ids.h
+++ b/include/linux/pci_ids.h
@@ -1382,6 +1382,8 @@
 #define PCI_DEVICE_ID_NVIDIA_GEFORCE_320M           0x08A0
 #define PCI_DEVICE_ID_NVIDIA_NFORCE_MCP79_SMBUS     0x0AA2
 #define PCI_DEVICE_ID_NVIDIA_NFORCE_MCP89_SATA	    0x0D85
+#define PCI_DEVICE_ID_NVIDIA_GB10_GEN5_X4           0x22CE
+#define PCI_DEVICE_ID_NVIDIA_GB10_GEN4_X1           0x22D0
 
 #define PCI_VENDOR_ID_IMS		0x10e0
 #define PCI_DEVICE_ID_IMS_TT128		0x9128
-- 
2.45.2

On Thu, Nov 13, 2025 at 04:44:06PM +0800, Johnny Chang wrote:
> Nvidia GB10 PCIe hosts will encounter problem occasionally
> after SBR(secondary bus reset) is applied.

Could you elaborate what kinds of problems occur, how often they occur, etc?

Thanks,

Lukas

On Thu, 2025-11-13 at 10:39 +0100, Lukas Wunner wrote:
> On Thu, Nov 13, 2025 at 04:44:06PM +0800, Johnny Chang wrote:
> > Nvidia GB10 PCIe hosts will encounter problem occasionally
> > after SBR(secondary bus reset) is applied.
> 
> Could you elaborate what kinds of problems occur, how often they
> occur, etc?

There is about 1/1000 chance that after SBR is applied, any further
access via this root port will be blocked and make system crash. 

Thanks,

Johnny