[PATCH 4.19 110/118] gnss: sirf: fix synchronous write timeout

From: Greg Kroah-Hartman
Date: Mon Nov 26 2018 - 06:06:16 EST


4.19-stable review patch. If anyone has any objections, please let me know.

------------------

From: Johan Hovold <johan@xxxxxxxxxx>

commit 1decef370456870bf448a565be95db636428e106 upstream.

Passing a timeout of zero to the synchronous serdev_device_write()
helper does currently not imply to wait forever (unlike passing zero to
serdev_device_wait_until_sent()). Instead, if there's insufficient
room in the write buffer, we'd end up with an incomplete write.

Fixes: d2efbbd18b1e ("gnss: add driver for sirfstar-based receivers")
Cc: stable <stable@xxxxxxxxxxxxxxx> # 4.19
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/gnss/sirf.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/gnss/sirf.c
+++ b/drivers/gnss/sirf.c
@@ -16,6 +16,7 @@
#include <linux/pm.h>
#include <linux/pm_runtime.h>
#include <linux/regulator/consumer.h>
+#include <linux/sched.h>
#include <linux/serdev.h>
#include <linux/slab.h>
#include <linux/wait.h>
@@ -83,7 +84,7 @@ static int sirf_write_raw(struct gnss_de
int ret;

/* write is only buffered synchronously */
- ret = serdev_device_write(serdev, buf, count, 0);
+ ret = serdev_device_write(serdev, buf, count, MAX_SCHEDULE_TIMEOUT);
if (ret < 0)
return ret;