USB: OHCI: Remove USB bus reset delay from OHCI handover code
authorAlan Stern <stern@rowland.harvard.edu>
Tue, 28 Aug 2018 14:57:25 +0000 (10:57 -0400)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Mon, 10 Sep 2018 18:05:02 +0000 (20:05 +0200)
commit87f88dfcde0ecde2a1136b8364099dddb9895b12
treeef05537b0ce24d2b6185873a0f566c93aca60b40
parentffa8a31b5b3b81f12a9d77a574cc0b25bb8e856e
USB: OHCI: Remove USB bus reset delay from OHCI handover code

Paul pointed out that the 50-ms sleep during OHCI initialization takes
up a large fraction of a system's boot time.  Things get worse when
there are two OHCI controllers present, each requiring 50 ms.

However, there really is no need to send a 50-ms reset signal out all
the root-hub ports during initialization.  The ports themselves will
be disabled, and the only way to enable a port is to reset it.
Therefore all attached USB devices will receive a proper reset in any
case.  The controller reset does not need to be long enough to reset
those other devices, so the 50-ms delay isn't necessary.

Without the delay, there is no remaining incentive for skipping the
reset when the controller is already in the RESET state.  This patch
removes the test, issuing the command unconditionally, and removes the
following delay.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Suggested-by: Paul Menzel <pmenzel@molgen.mpg.de>
Tested-by: Paul Menzel <pmenzel@molgen.mpg.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/usb/host/pci-quirks.c