[PATCH AUTOSEL 5.5 70/75] ASoC: SOF: trace: fix unconditional free in trace release

[Sasha Levin]

From: Kai Vehmanen <kai.vehmanen@xxxxxxxxxxxxxxx>

[ Upstream commit e6110114d18d330c05fd6de9f31283fd086a5a3a ]

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@xxxxxxxxxxxxxxx>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20200124213625.30186-5-pierre-louis.bossart@xxxxxxxxxxxxxxx
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 sound/soc/sof/trace.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/sound/soc/sof/trace.c b/sound/soc/sof/trace.c
index b0e4556c8536a..5bf63fa67fb09 100644
--- 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);
-- 
2.20.1