sound: oxygen: work around MCE when changing volume
commit852a95da5412bb513bf83ad1daa39992fa72b81e
authorClemens Ladisch <clemens@ladisch.de>
Mon, 7 Sep 2009 08:18:54 +0000 (7 10:18 +0200)
committerGreg Kroah-Hartman <gregkh@suse.de>
Thu, 24 Sep 2009 15:27:17 +0000 (24 08:27 -0700)
tree956a0a2a44f26aa4c1d5cd6a63b88390d2a8e5db
parent23b7ff36511e0aea0b054d0c7236f8f91509da07
sound: oxygen: work around MCE when changing volume

commit f1bc07af9a9edc5c1d4bdd971f7099316ed2e405 upstream.

When the volume is changed continuously (e.g., when the user drags a
volume slider with the mouse), the driver does lots of I2C writes.
Apparently, the sound chip can get confused when we poll the I2C status
register too much, and fails to complete a read from it.  On the PCI-E
models, the PCI-E/PCI bridge gets upset by this and generates a machine
check exception.

To avoid this, this patch replaces the polling with an unconditional
wait that is guaranteed to be long enough.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Tested-by: Johann Messner <johann.messner at jku.at>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
sound/pci/oxygen/oxygen_io.c