USB: serial: ftdi_sio: fix setting latency for unprivileged users

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commit bb246681b3 upstream.

Commit 557aaa7ffa ("ft232: support the ASYNC_LOW_LATENCY
flag") enables unprivileged users to set the FTDI latency timer,
but there was a logic flaw that skipped sending the corresponding
USB control message to the device.

Specifically, the device latency timer would not be updated until next
open, something which was later also inadvertently broken by commit
c19db4c9e4 ("USB: ftdi_sio: set device latency timeout at port
probe").

A recent commit c6dce26266 ("USB: serial: ftdi_sio: fix extreme
low-latency setting") disabled the low-latency mode by default so we now
need this fix to allow unprivileged users to again enable it.

Signed-off-by: Anthony Mallet <anthony.mallet@laas.fr>
[johan: amend commit message]
Fixes: 557aaa7ffa ("ft232: support the ASYNC_LOW_LATENCY flag")
Fixes: c19db4c9e4 ("USB: ftdi_sio: set device latency timeout at port probe").
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

...

This commit is contained in:

Anthony Mallet 2017-05-05 17:30:16 +02:00 • committed by Greg Kroah-Hartman

parent 2ea2f891fa

commit 038ccaa5d5

1 changed files with 1 additions and 1 deletions

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drivers/usb/serial/ftdi_sio.c

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