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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Takashi Iwai <tiwai@suse.de>
Subject: [PATCH 4.14 019/161] ALSA: hda/ca0132 - Avoid endless loop
Date:   Sun, 29 Dec 2019 18:17:47 +0100
Message-Id: <20191229162402.698914747@linuxfoundation.org>
In-Reply-To: <20191229162355.500086350@linuxfoundation.org>
References: <20191229162355.500086350@linuxfoundation.org>
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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
@@ -1300,13 +1300,14 @@ 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)