Commit 55abe816 authored Oct 27, 2016 by Ian Abbott Committed by Greg Kroah-Hartman Nov 07, 2016

staging: comedi: ni_tio: fix buggy ni_tio_clock_period_ps() return value



`ni_tio_clock_period_ps()` used to return the clock period in
picoseconds, and had a `BUG()` call for invalid cases.  It was changed
to pass the clock period back via a pointer parameter and return an
error for the invalid cases.  Unfortunately the code to handle
user-specified clock sources with user-specified clock period is still
returning the clock period the old way, which can lead to the caller not
getting the clock period, or seeing an unexpected error.  Fix it by
passing the clock period via the pointer parameter and returning `0`.

Fixes: b42ca86a ("staging: comedi: ni_tio: remove BUG() checks for ni_tio_get_clock_src()")
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Cc: <stable@vger.kernel.org> # 4.7+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 33c027ae

drivers/staging/comedi/drivers/ni_tio.c

+2 −1

Original line number	Original line	Diff line number	Diff line
	@@ -207,7 +207,8 @@ static int ni_tio_clock_period_ps(const struct ni_gpct *counter,
	* clock period is specified by user with prescaling		* clock period is specified by user with prescaling
	* already taken into account.		* already taken into account.
	*/		*/
	return counter->clock_period_ps;		*period_ps = counter->clock_period_ps;
			return 0;
	}		}

	switch (generic_clock_source & NI_GPCT_PRESCALE_MODE_CLOCK_SRC_MASK) {		switch (generic_clock_source & NI_GPCT_PRESCALE_MODE_CLOCK_SRC_MASK) {