[PATCH] xhci: fix U1/U2 handling for hardware with XHCI_INTEL_HOST quirk set
From: Michael Grzeschik <hidden>
Date: 2020-12-15 19:32:37
Subsystem:
the rest, usb subsystem, usb xhci driver · Maintainers:
Linus Torvalds, Greg Kroah-Hartman, Mathias Nyman
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>
---
drivers/usb/host/xhci.c | 24 ++++++++++++------------
1 file changed, 12 insertions(+), 12 deletions(-)
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index f4cedcaee14b3..0385ef9cb628b 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c@@ -4640,19 +4640,19 @@ 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. */
@@ -4704,19 +4704,19 @@ 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
--
2.29.2