[RFC PATCH] PCI: Avoid bus reset for Realtek RTL8126

[RFC PATCH] PCI: Avoid bus reset for Realtek RTL8126

[John Garry]

From testing on a Orion O6 board, a bus level reset for a RTL8126 may not
recover:
root@radxa-kernel:/sys/devices/pci0000:00/0000:00:00.0/0000:01:00.0# more reset_method
bus
root@radxa-kernel:/sys/devices/pci0000:00/0000:00:00.0/0000:01:00.0# echo 1 > reset
 r8169 0000:01:00.0: resetting
 r8169 0000:01:00.0: not ready 1023ms after bus reset; waiting
 r8169 0000:01:00.0: not ready 2047ms after bus reset; waiting
 r8169 0000:01:00.0: not ready 4095ms after bus reset; waiting
 r8169 0000:01:00.0: not ready 8191ms after bus reset; waiting
 r8169 0000:01:00.0: not ready 16383ms after bus reset; waiting
 r8169 0000:01:00.0: not ready 32767ms after bus reset; waiting
 SError Interrupt on CPU6, code 0x00000000be000011 -- SError

Add a quirk to avoid this reset method.

Signed-off-by: John Garry <john.garry@arm.com>
---
I'm sending as an RFC as I am not sure that this is an issue with the
development board and not the controller.

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 7f1f47ea2ee4..69eef714838a 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -3850,6 +3850,9 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ASMEDIA, 0x1164, quirk_no_bus_reset);
 /* Intel DG1 0x4905 may not recover from bus reset */
 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x4905, quirk_no_bus_reset);
 
+/* Realtek RTL8126 may not recover from a bus reset */
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_REALTEK, 0x8126, quirk_no_bus_reset);
+
 static void quirk_no_pm_reset(struct pci_dev *dev)
 {
 	/*
-- 
2.47.3