This is a note to let you know that I've just added the patch titled

staging: comedi: cb_pcidas: Allow 2-channel commands for AO subdevice

to my staging git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git in the staging-linus branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.

If you have any questions about this process, please let me know.

From 647a6002cb41d358d9ac5de101a8a6dc74748a59 Mon Sep 17 00:00:00 2001

From: Ian Abbott abbotti@mev.co.uk Date: Wed, 21 Oct 2020 13:21:42 +0100 Subject: staging: comedi: cb_pcidas: Allow 2-channel commands for AO subdevice

The "cb_pcidas" driver supports asynchronous commands on the analog output (AO) subdevice for those boards that have an AO FIFO. The code (in `cb_pcidas_ao_check_chanlist()` and `cb_pcidas_ao_cmd()`) to validate and set up the command supports output to a single channel or to two channels simultaneously (the boards have two AO channels). However, the code in `cb_pcidas_auto_attach()` that initializes the subdevices neglects to initialize the AO subdevice's `len_chanlist` member, leaving it set to 0, but the Comedi core will "correct" it to 1 if the driver neglected to set it. This limits commands to use a single channel (either channel 0 or 1), but the limit should be two channels. Set the AO subdevice's `len_chanlist` member to be the same value as the `n_chan` member, which will be 2.

Cc: stable@vger.kernel.org Signed-off-by: Ian Abbott abbotti@mev.co.uk Link: https://lore.kernel.org/r/20201021122142.81628-1-abbotti@mev.co.uk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/staging/comedi/drivers/cb_pcidas.c | 1 + 1 file changed, 1 insertion(+)

diff --git a/drivers/staging/comedi/drivers/cb_pcidas.c b/drivers/staging/comedi/drivers/cb_pcidas.c index 48ec2ee953dc..d740c4782775 100644 --- a/drivers/staging/comedi/drivers/cb_pcidas.c +++ b/drivers/staging/comedi/drivers/cb_pcidas.c @@ -1342,6 +1342,7 @@ static int cb_pcidas_auto_attach(struct comedi_device *dev, if (dev->irq && board->has_ao_fifo) { dev->write_subdev = s; s->subdev_flags |= SDF_CMD_WRITE; + s->len_chanlist = s->n_chan; s->do_cmdtest = cb_pcidas_ao_cmdtest; s->do_cmd = cb_pcidas_ao_cmd; s->cancel = cb_pcidas_ao_cancel;