ASoC: SOF: trace: fix unconditional free in trace release

Check if DMA pages were successfully allocated in initialization
before calling free. For many types of memory (like sgbufs)
the extra free is harmless, but not all backends track allocation
state, so add an explicit check.

Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20200124213625.30186-5-pierre-louis.bossart@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/sound/soc/sof/trace.c b/sound/soc/sof/trace.c
index 4bb6503..d815090 100644 (file)
--- a/sound/soc/sof/trace.c
+++ b/sound/soc/sof/trace.c
@@ -343,7 +343,10 @@ void snd_sof_free_trace(struct snd_sof_dev *sdev)
 
        snd_sof_release_trace(sdev);
 
-       snd_dma_free_pages(&sdev->dmatb);
-       snd_dma_free_pages(&sdev->dmatp);
+       if (sdev->dma_trace_pages) {
+               snd_dma_free_pages(&sdev->dmatb);
+               snd_dma_free_pages(&sdev->dmatp);
+               sdev->dma_trace_pages = 0;
+       }
 }
 EXPORT_SYMBOL(snd_sof_free_trace);