staging: comedi: cb_pcidas: prevent "empty acquisition" async commands
authorH Hartley Sweeten <hsweeten@visionengravers.com>
Tue, 9 Sep 2014 23:15:45 +0000 (16:15 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 11 Sep 2014 21:35:20 +0000 (14:35 -0700)
commitc5d9973b046fb8e0b0f3a8ad925d0033eec59856
treef2d493808cc5f688ee4bb46d3845463092d68257
parent1dabb50199791d60b15ddfc958a8b56e5ea26460
staging: comedi: cb_pcidas: prevent "empty acquisition" async commands

This driver currently allows a cmd->stop_src == TRIG_COUNT with a cmd->stop_arg
of 0 for both the analog input and output async commands. The (*do_cmd) for
both subdevices sets up and starts the command without handling the "empty
acquisition". This results in the interrupt functions 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/cb_pcidas.c