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

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This reverts commit 5d5323a6f3.

That commit effectively disabled Intel host initiated U1/U2 lpm for devices
with periodic endpoints.

Before that commit we disabled host initiated U1/U2 lpm if the exit latency
was larger than any periodic endpoint service interval, this is according
to xhci spec xhci 1.1 specification section 4.23.5.2

After that commit we incorrectly checked that service interval was smaller
than U1/U2 inactivity timeout. This is not relevant, and can't happen for
Intel hosts as previously set U1/U2 timeout = 105% * service interval.

Patch claimed it solved cases where devices can't be enumerated because of
bandwidth issues. This might be true but it's a side effect of accidentally
turning off lpm.

exit latency calculations have been revised since then

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20210820123503.2605901-5-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

...

This commit is contained in:

Mathias Nyman 2021-08-20 15:35:01 +03:00 • committed by Greg Kroah-Hartman

parent 94f339147f

commit 2847c46c61

1 changed files with 12 additions and 12 deletions

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drivers/usb/host/xhci.c

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