[PATCH 0/2] usb: xhci: add xhci-no-soft-retry-quirk

[Matt Eaton via B4 Relay]

This series adds an opt-in device property so platform xHCI hosts can
request the XHCI_NO_SOFT_RETRY quirk, currently only reachable from
xhci-pci matched against two AMD Promontory PCI ids.

Motivating case: the Synopsys DWC3 xHCI instances on Qualcomm IPQ4019
mishandle xHCI 1.0 Soft Retry. A Stop Endpoint command landing on a
just-soft-retry-reset endpoint wedges the command ring; the
stop-endpoint watchdog then kills the host five seconds later. Setting
the property falls back to the pre-Soft-Retry recovery path (full
endpoint reset), which the vendor's 4.4 kernel uses unconditionally
and which is well tolerated on this hardware.

Patch 1 documents the property. Patch 2 wires it into xhci-plat.c.

The devicetree change enabling this on IPQ4019 is being sent
separately to linux-arm-msm, since this series only adds the
mechanism.

Signed-off-by: Matt Eaton <linux@xxxxxxxxxxxxxx>
---
Matt Eaton (2):
      dt-bindings: usb: xhci: add xhci-no-soft-retry-quirk
      usb: xhci-plat: add xhci-no-soft-retry-quirk device property

 Documentation/devicetree/bindings/usb/usb-xhci.yaml | 4 ++++
 drivers/usb/host/xhci-plat.c                        | 3 +++
 2 files changed, 7 insertions(+)
---
base-commit: 45c13f3f9e3bb15fd89ff2864c6f627a3b4b4229
change-id: 20260828-xhci-no-soft-retry-4af6c93dc7d2

Best regards,
--  
Matt Eaton <linux@xxxxxxxxxxxxxx>