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

The commit 0472bf06c6 ("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: 0472bf06c6 ("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>
zero-sugar-mainline-defconfig
Michael Grzeschik 2020-12-15 20:31:47 +01:00 committed by Greg Kroah-Hartman
parent 0f041b8592
commit 5d5323a6f3
1 changed files with 16 additions and 16 deletions
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32
drivers/usb/host/xhci.c
View File

@ -4770,19 +4770,19 @@ static u16 xhci_calculate_u1_timeout(struct xhci_hcd *xhci,
{
unsigned long long timeout_ns;
/* 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) {
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;
/* 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) <= timeout_ns) {
dev_dbg(&udev->dev, "Disable U1, ESIT shorter than exit latency\n");
return USB3_LPM_DISABLED;
}
}
/* The U1 timeout is encoded in 1us intervals.
* Don't return a timeout of zero, because that's USB3_LPM_DISABLED.
*/
@ -4834,19 +4834,19 @@ static u16 xhci_calculate_u2_timeout(struct xhci_hcd *xhci,
{
unsigned long long timeout_ns;
/* 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) {
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;
/* 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) <= timeout_ns) {
dev_dbg(&udev->dev, "Disable U2, ESIT shorter than exit latency\n");
return USB3_LPM_DISABLED;
}
}
/* 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