From: Sven Eckelmann <sven@narfation.org>
Date: Sun, 17 Nov 2013 19:38:21 +0000 (+0100)
Subject: HID: sony: Send FF commands in non-atomic context
X-Git-Tag: v3.13-rc2~18^2~6
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9f323b681139d99beb456aff08cf339b29f3c78d;p=pandora-kernel.git

HID: sony: Send FF commands in non-atomic context

The ff_memless has a timer running which gets run in an atomic context and
calls the play_effect callback. The callback function for sony uses the
hid_output_raw_report (overwritten by sixaxis_usb_output_raw_report) function
to handle differences in the control message format. It is not safe for an
atomic context because it may sleep later in usb_start_wait_urb.

This "scheduling while atomic" can cause the system to lock up. A workaround is
to make the force feedback state update using work_queues and use the
play_effect function only to enqueue the work item.

Reported-by: Simon Wood <simon@mungewell.org>
Reported-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wood <simon@mungewell.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
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