This is a note to let you know that I've just added the patch titled

usb: xhci: do not perform Soft Retry for some xHCI hosts

to my usb git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git in the usb-linus branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.

If you have any questions about this process, please let me know.

From a4a251f8c23518899d2078c320cf9ce2fa459c9f Mon Sep 17 00:00:00 2001

From: Stanislaw Gruszka stf_xl@wp.pl Date: Thu, 11 Mar 2021 13:53:50 +0200 Subject: usb: xhci: do not perform Soft Retry for some xHCI hosts

On some systems rt2800usb and mt7601u devices are unable to operate since commit f8f80be501aa ("xhci: Use soft retry to recover faster from transaction errors")

Seems that some xHCI controllers can not perform Soft Retry correctly, affecting those devices.

To avoid the problem add xhci->quirks flag that restore pre soft retry xhci behaviour for affected xHCI controllers. Currently those are AMD_PROMONTORYA_4 and AMD_PROMONTORYA_2, since it was confirmed by the users: on those xHCI hosts issue happen and is gone after disabling Soft Retry.

[minor commit message rewording for checkpatch -Mathias]

Fixes: f8f80be501aa ("xhci: Use soft retry to recover faster from transaction errors") Cc: stable@vger.kernel.org # 4.20+ Reported-by: Bernhard bernhard.gebetsberger@gmx.at Tested-by: Bernhard bernhard.gebetsberger@gmx.at Signed-off-by: Stanislaw Gruszka stf_xl@wp.pl Signed-off-by: Mathias Nyman mathias.nyman@linux.intel.com Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=202541 Link: https://lore.kernel.org/r/20210311115353.2137560-2-mathias.nyman@linux.intel... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/usb/host/xhci-pci.c | 5 +++++ drivers/usb/host/xhci-ring.c | 3 ++- drivers/usb/host/xhci.h | 1 + 3 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c index 84da8406d5b4..1f989a49c8c6 100644 --- a/drivers/usb/host/xhci-pci.c +++ b/drivers/usb/host/xhci-pci.c @@ -295,6 +295,11 @@ static void xhci_pci_quirks(struct device *dev, struct xhci_hcd *xhci) pdev->device == 0x9026) xhci->quirks |= XHCI_RESET_PLL_ON_DISCONNECT;

+ if (pdev->vendor == PCI_VENDOR_ID_AMD && + (pdev->device == PCI_DEVICE_ID_AMD_PROMONTORYA_2 || + pdev->device == PCI_DEVICE_ID_AMD_PROMONTORYA_4)) + xhci->quirks |= XHCI_NO_SOFT_RETRY; + if (xhci->quirks & XHCI_RESET_ON_RESUME) xhci_dbg_trace(xhci, trace_xhci_dbg_quirks, "QUIRK: Resetting on resume"); diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index 5e548a1c93ab..ce38076901e2 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -2484,7 +2484,8 @@ static int process_bulk_intr_td(struct xhci_hcd *xhci, struct xhci_td *td, remaining = 0; break; case COMP_USB_TRANSACTION_ERROR: - if ((ep_ring->err_count++ > MAX_SOFT_RETRY) || + if (xhci->quirks & XHCI_NO_SOFT_RETRY || + (ep_ring->err_count++ > MAX_SOFT_RETRY) || le32_to_cpu(slot_ctx->tt_info) & TT_SLOT) break;

diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h index d41de5dc0452..ca822ad3b65b 100644 --- a/drivers/usb/host/xhci.h +++ b/drivers/usb/host/xhci.h @@ -1891,6 +1891,7 @@ struct xhci_hcd { #define XHCI_SKIP_PHY_INIT BIT_ULL(37) #define XHCI_DISABLE_SPARSE BIT_ULL(38) #define XHCI_SG_TRB_CACHE_SIZE_QUIRK BIT_ULL(39) +#define XHCI_NO_SOFT_RETRY BIT_ULL(40)

unsigned int num_active_eps; unsigned int limit_active_eps;