Commit eb3a1323 authored by H Hartley Sweeten's avatar H Hartley Sweeten Committed by Greg Kroah-Hartman
Browse files

staging: comedi: comedi_buf: make comedi_buf_write_samples() add samples that fit 



This function currently fails if the number of samples to add would
overflow the async buffer. Modify it to add the samples that fit so
at least some of the sample data is returned to the user.

Signed-off-by: default avatarH Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: default avatarIan Abbott <abbotti@mev.co.uk>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 2b365fa9

drivers/staging/comedi/comedi_buf.c

+6 −2
Original line number Diff line number Diff line
@@ -484,12 +484,16 @@ unsigned int comedi_buf_write_samples(struct comedi_subdevice *s, 
	unsigned int max_samples;

	unsigned int nbytes;



	/* make sure there is enought room in the buffer for all the samples */

	/*

	 * Make sure there is enough room in the buffer for all the samples.

	 * If not, clamp the nsamples to the number that will fit, flag the

	 * buffer overrun and add the samples that fit.

	 */

	max_samples = comedi_buf_write_n_available(s) / bytes_per_sample(s);

	if (nsamples > max_samples) {

		dev_warn(s->device->class_dev, "buffer overrun\n");

		s->async->events |= COMEDI_CB_OVERFLOW;

		return 0;

		nsamples = max_samples;

	}



	if (nsamples == 0)