[PATCH 5.4 58/92] USB: xhci: fix U1/U2 handling for hardware with XHCI_INTEL_HOST quirk set
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2021-01-11 13:38:32
Also in:
lkml
From: Michael Grzeschik <redacted>
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 <redacted>
Cc: stable <redacted>
Link: https://lore.kernel.org/r/20201215193147.11738-1-m.grzeschik@pengutronix.de (local)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/usb/host/xhci.c | 24 ++++++++++++------------
1 file changed, 12 insertions(+), 12 deletions(-)
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c@@ -4642,19 +4642,19 @@ static u16 xhci_calculate_u1_timeout(str { 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. */
@@ -4706,19 +4706,19 @@ static u16 xhci_calculate_u2_timeout(str { 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