tree ce63aa5c1580b217af7ddd21fecee7cd2cca6c77
parent aab2d4086a1876fcff282aa36e2d4a92aa9935c9
author Jason Wessel <jason.wessel@windriver.com> 1250800796 -0500
committer Greg Kroah-Hartman <gregkh@suse.de> 1253713598 -0700

USB: ehci-dbgp: errata for EHCI debug/host controller synchronization

On some EHCI debug controllers after the host controller driver is
activated, the debug controller will occasionally fail to submit a
bulk write URB.  On controllers that exhibit this behavior a dummy
bulk write must get submitted to resynchronize the device.

The "dummy bulk write" does not get received by the host attached to
the other end of the usb debug device.  The usb debug device simply
acknowledges the "dummy bulk write" and returns to a usable state.

The behavior, without this patch is that you see missing text from a
complete kernel boot when using the keep option to the earlyprintk
kernel argument.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>