On 9/1/26 9:39 AM, Mahesh J Salgaonkar wrote:
On 2026-08-21 18:04:01 Fri, Avinash Roy wrote:
From: Shivaprasad G Bhat <[email protected]>
The IBM Spyre accelerator (PCI ID 1014:06a7) requires a dedicated warm
reset method for reliable EEH recovery on pSeries/ppc64 platforms.
FLR alone is insufficient because it does not re-initialize firmware
state machine for the current version of the card. The existing API
pci_set_pcie_reset_state() is used to drive the platform-level
PERST# using the EEH interfaces by adding a device specific quirk.
The reset function is placed in arch/powerpc/platforms/pseries/pci.c
where the EEH infrastructure is already present, declared in
pseries.h, and registered in the generic pci_dev_reset_methods[] table
in drivers/pci/quirks.c under a CONFIG_PPC_PSERIES guard.
This reset method is only registered when CONFIG_PPC_PSERIES is enabled,
so it is not available on other platforms.
Reset sequence:
- Assert PERST# via pcie_warm_reset, hold 250 ms
- Deassert PERST# via pcie_deassert_reset
- Wait 250 ms for PCIe link retrain
Signed-off-by: Avinash Roy <[email protected]>
Signed-off-by: Shivaprasad G Bhat <[email protected]>
---
Changelog
v1:
https://lore.kernel.org/linux-pci/[email protected]/
Reworded the commit message to highlight the warm reset requirement being
a need of the current card and not a platform deficiency.
diff --git a/arch/powerpc/platforms/pseries/pci.c
b/arch/powerpc/platforms/pseries/pci.c
index 84e4ffe957a8..7aa58d57208f 100644
--- a/arch/powerpc/platforms/pseries/pci.c
+++ b/arch/powerpc/platforms/pseries/pci.c
@@ -11,6 +11,7 @@
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/string.h>
+#include <linux/delay.h>
#include <asm/eeh.h>
#include <asm/pci-bridge.h>
@@ -236,6 +237,41 @@ static void fixup_winbond_82c105(struct pci_dev* dev)
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_WINBOND, PCI_DEVICE_ID_WINBOND_82C105,
fixup_winbond_82c105);
+/*
+ * Reset Spyre adapter using pci_set_pcie_reset_state()
+ * This is specifically for PPC platforms where EEH (Enhanced Error Handling)
+ * requires this reset method for proper device recovery.
+ */
+int reset_spyre(struct pci_dev *dev, bool probe)
+{
+ int ret;
+
+ if (probe)
+ return 0;
+
+ /* Assert warm reset */
+ ret = pci_set_pcie_reset_state(dev, pcie_warm_reset);
+ if (ret) {
+ pci_err(dev, "Failed to assert reset: %d\n", ret);
+ return ret;
+ }
+
+ /* Wait for reset to take effect */
+ msleep(250);
How did you arriver on this number ? Is this time defined by
hardware/firmware specs for reset ? Also, Can you #define the value 250
and use macro instead of constant numbmer.
This was the delay shared by the hardware team derived from their
calibrations.
Thanks,
Avinash
+
+ /* Deassert reset */
+ ret = pci_set_pcie_reset_state(dev, pcie_deassert_reset);
+ if (ret) {
+ pci_err(dev, "Failed to deassert reset: %d\n", ret);
+ return ret;
+ }
+
+ /* Wait for device to recover */
+ msleep(250);
same here.
+
+ return 0;
+}
+
Thanks,
-Mahesh.
