staging: comedi: das1800: document the spinlock
authorH Hartley Sweeten <hsweeten@visionengravers.com>
Fri, 8 Apr 2016 19:41:53 +0000 (12:41 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 29 Apr 2016 05:16:10 +0000 (22:16 -0700)
commit983330210fe138e1194e0b2ccca02400ae41c0be
treebc35d98759ab6c1c6e18e9c7e9e103ff9c478407
parentfb90ec01bc8364a6ae7b8436c759f7541ebfd37f
staging: comedi: das1800: document the spinlock

The comedi_device spinlock is used to protect the indirect addressing
selected by the DAS1800_SELECT register. It also prevents races between
the interrupt handler and the analog input (*poll).

Update the comments to make this clear.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/staging/comedi/drivers/das1800.c