Patch "staging: comedi: ni_tio: fix buggy ni_tio_clock_period_ps() return value" has been added to the 4.8-stable tree

Patch "staging: comedi: ni_tio: fix buggy ni_tio_clock_period_ps() return value" has been added to the 4.8-stable tree

[gregkh]

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

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

to the 4.8-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     staging-comedi-ni_tio-fix-buggy-ni_tio_clock_period_ps-return-value.patch
and it can be found in the queue-4.8 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 55abe8165f31ffb83ce8b24da959b61362dca4c4 Mon Sep 17 00:00:00 2001
From: Ian Abbott <abbotti@mev.co.uk>
Date: Thu, 27 Oct 2016 20:28:36 +0100
Subject: staging: comedi: ni_tio: fix buggy ni_tio_clock_period_ps() return value

From: Ian Abbott <abbotti@mev.co.uk>

commit 55abe8165f31ffb83ce8b24da959b61362dca4c4 upstream.

`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: b42ca86ad605 ("staging: comedi: ni_tio: remove BUG() checks for ni_tio_get_clock_src()")
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/staging/comedi/drivers/ni_tio.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/staging/comedi/drivers/ni_tio.c
+++ b/drivers/staging/comedi/drivers/ni_tio.c
@@ -207,7 +207,8 @@ static int ni_tio_clock_period_ps(const
 		 * clock period is specified by user with prescaling
 		 * 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) {


Patches currently in stable-queue which might be from abbotti@mev.co.uk are

queue-4.8/staging-comedi-ni_tio-fix-buggy-ni_tio_clock_period_ps-return-value.patch