From: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Date: Fri, 19 Feb 2016 14:44:41 +0000 (+0000)
Subject: ASoC: wm_adsp: Avoid narrow race condition on compr pointer
X-Git-Tag: v4.6-rc1~101^2~9^2~8^5~4
X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=c7dae7c4c60693286298e300b3d140c8cff46daa;p=linux.git

ASoC: wm_adsp: Avoid narrow race condition on compr pointer

There is a very small window between then wm_adsp_compr_free gets call
and when the DSP is actually powered down. If we get an IRQ from the DSP
in this window then the wm_adsp_compr pointer will be NULL. This patch
adds a check for this into the IRQ handler to avoid any issues when this
happens.

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
---

diff --git a/sound/soc/codecs/wm_adsp.c b/sound/soc/codecs/wm_adsp.c
index 68b85ee67586..cb49a632462a 100644
--- a/sound/soc/codecs/wm_adsp.c
+++ b/sound/soc/codecs/wm_adsp.c
@@ -2845,7 +2845,7 @@ int wm_adsp_compr_handle_irq(struct wm_adsp *dsp)
 		goto out;
 	}
 
-	if (compr->stream)
+	if (compr && compr->stream)
 		snd_compr_fragment_elapsed(compr->stream);
 
 out: