ASoC: SOF: Intel: hda: hda-dai: fix oops on hda_link .hw_free

When the PCM_PARAM IPC fails while configuring the FE, the kernel
oopses in the HDaudio link DMA .hw_free operation. The root cause is a
NULL dma_data since the BE .hw_params was never called by the SOC
core.

This error can also happen if the HDaudio link DMA configuration IPC
fails in the BE .hw_params.

This patches makes sure the dma_data is properly saved in .hw_params,
and tested before being use in hw_free.

GitHub issue: https://github.com/thesofproject/linux/issues/1417

Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-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/20191218000518.5830-3-pierre-louis.bossart@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/sound/soc/sof/intel/hda-dai.c b/sound/soc/sof/intel/hda-dai.c
index 8796f38..896d219 100644 (file)
--- a/sound/soc/sof/intel/hda-dai.c
+++ b/sound/soc/sof/intel/hda-dai.c
@@ -216,6 +216,8 @@ static int hda_link_hw_params(struct snd_pcm_substream *substream,
                link_dev = hda_link_stream_assign(bus, substream);
                if (!link_dev)
                        return -EBUSY;
+
+               snd_soc_dai_set_dma_data(dai, substream, (void *)link_dev);
        }
 
        stream_tag = hdac_stream(link_dev)->stream_tag;
@@ -228,8 +230,6 @@ static int hda_link_hw_params(struct snd_pcm_substream *substream,
        if (ret < 0)
                return ret;
 
-       snd_soc_dai_set_dma_data(dai, substream, (void *)link_dev);
-
        link = snd_hdac_ext_bus_get_link(bus, codec_dai->component->name);
        if (!link)
                return -EINVAL;
@@ -361,6 +361,13 @@ static int hda_link_hw_free(struct snd_pcm_substream *substream,
        bus = hstream->bus;
        rtd = snd_pcm_substream_chip(substream);
        link_dev = snd_soc_dai_get_dma_data(dai, substream);
+
+       if (!link_dev) {
+               dev_dbg(dai->dev,
+                       "%s: link_dev is not assigned\n", __func__);
+               return -EINVAL;
+       }
+
        hda_stream = hstream_to_sof_hda_stream(link_dev);
 
        /* free the link DMA channel in the FW */