USB: xhci: fix U1/U2 handling for hardware with XHCI_INTEL_HOST quirk set

commit 5d5323a6f3625f101dbfa94ba3ef7706cce38760 upstream.

The commit 0472bf06c6fd ("xhci: Prevent U1/U2 link pm states if exit
latency is too long") was constraining the xhci code not to allow U1/U2
sleep states if the latency to wake up from the U-states reached the
service interval of an periodic endpoint. This fix was not taking into
account that in case the quirk XHCI_INTEL_HOST is set, the wakeup time
will be calculated and configured differently.

It checks for u1_params.mel/u2_params.mel as a limit. But the code could
decide to write another MEL into the hardware. This leads to broken
cases where not enough bandwidth is available for other devices:

usb 1-2: can't set config #1, error -28

This patch is fixing that case by checking for timeout_ns after the
wakeup time was calculated depending on the quirks.

Fixes: 0472bf06c6fd ("xhci: Prevent U1/U2 link pm states if exit latency is too long")
Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20201215193147.11738-1-m.grzeschik@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index d4a8d0e..73f1373 100644 (file)
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -4646,19 +4646,19 @@ static u16 xhci_calculate_u1_timeout(struct xhci_hcd *xhci,
 {
        unsigned long long timeout_ns;
 
+       if (xhci->quirks & XHCI_INTEL_HOST)
+               timeout_ns = xhci_calculate_intel_u1_timeout(udev, desc);
+       else
+               timeout_ns = udev->u1_params.sel;
+
        /* Prevent U1 if service interval is shorter than U1 exit latency */
        if (usb_endpoint_xfer_int(desc) || usb_endpoint_xfer_isoc(desc)) {
-               if (xhci_service_interval_to_ns(desc) <= udev->u1_params.mel) {
+               if (xhci_service_interval_to_ns(desc) <= timeout_ns) {
                        dev_dbg(&udev->dev, "Disable U1, ESIT shorter than exit latency\n");
                        return USB3_LPM_DISABLED;
                }
        }
 
-       if (xhci->quirks & XHCI_INTEL_HOST)
-               timeout_ns = xhci_calculate_intel_u1_timeout(udev, desc);
-       else
-               timeout_ns = udev->u1_params.sel;
-
        /* The U1 timeout is encoded in 1us intervals.
         * Don't return a timeout of zero, because that's USB3_LPM_DISABLED.
         */
@@ -4710,19 +4710,19 @@ static u16 xhci_calculate_u2_timeout(struct xhci_hcd *xhci,
 {
        unsigned long long timeout_ns;
 
+       if (xhci->quirks & XHCI_INTEL_HOST)
+               timeout_ns = xhci_calculate_intel_u2_timeout(udev, desc);
+       else
+               timeout_ns = udev->u2_params.sel;
+
        /* Prevent U2 if service interval is shorter than U2 exit latency */
        if (usb_endpoint_xfer_int(desc) || usb_endpoint_xfer_isoc(desc)) {
-               if (xhci_service_interval_to_ns(desc) <= udev->u2_params.mel) {
+               if (xhci_service_interval_to_ns(desc) <= timeout_ns) {
                        dev_dbg(&udev->dev, "Disable U2, ESIT shorter than exit latency\n");
                        return USB3_LPM_DISABLED;
                }
        }
 
-       if (xhci->quirks & XHCI_INTEL_HOST)
-               timeout_ns = xhci_calculate_intel_u2_timeout(udev, desc);
-       else
-               timeout_ns = udev->u2_params.sel;
-
        /* The U2 timeout is encoded in 256us intervals */
        timeout_ns = DIV_ROUND_UP_ULL(timeout_ns, 256 * 1000);
        /* If the necessary timeout value is bigger than what we can set in the