patch "staging: comedi: ni_tio: fix buggy ni_tio_clock_period_ps() return" added to staging-linus

patch "staging: comedi: ni_tio: fix buggy ni_tio_clock_period_ps() return" added to staging-linus

[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

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 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

`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>
Cc: <stable@vger.kernel.org> # 4.7+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/staging/comedi/drivers/ni_tio.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/staging/comedi/drivers/ni_tio.c b/drivers/staging/comedi/drivers/ni_tio.c
index 7043eb0543f6..5ab49a798164 100644
--- 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 struct ni_gpct *counter,
 		 * 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) {
-- 
2.10.2