staging: comedi: das16m1: prevent "empty acquisition" async command
authorH Hartley Sweeten <hsweeten@visionengravers.com>
Tue, 9 Sep 2014 23:15:47 +0000 (16:15 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 11 Sep 2014 21:35:20 +0000 (14:35 -0700)
commit1a021d6387337c828c6e15c7fc65f3e013163f89
treeedfabe08f6dea1ba31721298289513c67f6b685e
parent2c8af779c4c205ff379dcc3ac52831730ec0f5d5
staging: comedi: das16m1: prevent "empty acquisition" async command

This driver currently allows a cmd->stop_src == TRIG_COUNT with a cmd->stop_arg
of 0. The (*do_cmd) then sets up and starts the command without handling the "empty
acquisition". This results in the interrupt function trying to transfer 0 data
samples.

Validate that the cmd->stop_arg is >= 1 in the (*do_cmdtest) to prevent the
"empty acquisition".

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/das16m1.c