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Code Issues Releases Packages Activity

usb: hub: use shorter 120ms post resume hold for SS root hubs

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Holding a USB3 hub PM runtime reference for 200ms at hub resume triggers
an AMD platform issue.  Users running Android adb report crashes after
adb has been polling and waking up the USB subsystem once a second for
some time.  Vendors are working on a solution.  Disabling USB runtime PM
is one way to prevent this issue, but it is also proven that reducing the
hold time to 120ms in resume also mitigates it.  See Link for more
details.

Reducing the hold time to 120ms for the USB3 roothub is in itself a valid
change and optimization, as the current 200ms is excessive: a root hub
has no upstream suspended hub whose wake propagation needs to be
accounted for, but still need some time for USB3 link training to
complete.

Keep the 200ms hold for external hubs that commit 8f5b7e2bec
("usb: hub: fix detection of high tier USB3 devices behind suspended
hubs") is intended for.

Reported-by: Mathieu Fluhr <mathieu.fluhr@gmail.com>
Link: https://lore.kernel.org/all/CAPyJwA_D9qw0T72f8zwM1yKjP+To=maVANbcdsWM7yRmbBxYvw@mail.gmail.com/
Cc: stable <stable@kernel.org>
Fixes: 8f5b7e2bec ("usb: hub: fix detection of high tier USB3 devices behind suspended hubs")
Signed-off-by: Lovekesh Solanki <lovekeshsolanki00@gmail.com>
Acked-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://patch.msgid.link/20260903112903.542719-1-lovekeshsolanki00@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Lovekesh Solanki 2026-09-03 16:59:03 +05:30 • committed by Greg Kroah-Hartman
commit 29480b05e6
1 changed files with 6 additions and 1 deletions
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