[PATCH 5.4 041/434] ALSA: hda/ca0132 - Avoid endless loop

Greg Kroah-Hartman
2019-12-29T17:43:05Z

From: Takashi Iwai <tiwai@suse.de>

commit cb04fc3b6b076f67d228a0b7d096c69ad486c09c upstream.

Introduce a timeout to dspio_clear_response_queue() so that it won't
be caught in an endless loop even if the hardware doesn't respond
properly.

Fixes: a73d511c4867 ("ALSA: hda/ca0132: Add unsol handler for DSP and jack detection")
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20191213085111.22855-3-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
sound/pci/hda/patch_ca0132.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

--- a/sound/pci/hda/patch_ca0132.c
+++ b/sound/pci/hda/patch_ca0132.c
@@ -1809,13 +1809,14 @@ struct scp_msg {

static void dspio_clear_response_queue(struct hda_codec *codec)
{
+ unsigned long timeout = jiffies + msecs_to_jiffies(1000);
unsigned int dummy = 0;
- int status = -1;
+ int status;

/* clear all from the response queue */
do {
status = dspio_read(codec, &dummy);
- } while (status == 0);
+ } while (status == 0 && time_before(jiffies, timeout));
}

static int dspio_get_response_data(struct hda_codec *codec)