ASoC: tegra-alt: Avoid reg access after shutdown

Below are the hypothetical scenarios
- Drivers are in suspend state while reboot and PCM Open call from
  userspace is received after driver shutdown [APE is power gated
  already]
- PM domain handling doesn't ensure proper functionality after driver
  shutdown is called

The change handles with the below fix
- Will prevent any reg access in runtime resume of drivers and avoid
  opening pcm devices.

Bug 200333417

Change-Id: Ieba2a063342cd1e7becb79a0135cb2b8ec373a61
Signed-off-by: Mohan Kumar <mkumard@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1539396
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: svccoveritychecker <svccoveritychecker@nvidia.com>
GVS: Gerrit_Virtual_Submit
Reviewed-by: Dipesh Gandhi <dipeshg@nvidia.com>
Reviewed-by: Ravindra Lokhande <rlokhande@nvidia.com>

1 files changed, 18 insertions, 4 deletions

diff --git a/sound/soc/tegra-alt/tegra210_adsp_alt.c b/sound/soc/tegra-alt/tegra210_adsp_alt.c
index d9e1250e7..eafc9481b 100644
--- a/sound/soc/tegra-alt/tegra210_adsp_alt.c
+++ b/sound/soc/tegra-alt/tegra210_adsp_alt.c
@@ -171,6 +171,7 @@ struct tegra210_adsp {
         struct mutex mutex;
         int init_done;
         int adsp_started;
+        bool is_shutdown;
         uint32_t adma_ch_page;
         uint32_t adma_ch_start;
         uint32_t adma_ch_cnt;
@@ -1247,7 +1248,7 @@ static int tegra210_adsp_compr_open(struct snd_compr_stream *cstream)
 
         dev_vdbg(adsp->dev, "%s : DAI ID %d", __func__, rtd->codec_dai->id);
 
-        if (!adsp->init_done)
+        if (!adsp->init_done || adsp->is_shutdown)
                 return -ENODEV;
 
         if (!adsp->pcm_path[fe_reg][cstream->direction].fe_reg ||
@@ -1572,6 +1573,9 @@ static int tegra210_adsp_pcm_open(struct snd_pcm_substream *substream)
 
         dev_vdbg(adsp->dev, "%s", __func__);
 
+        if (adsp->is_shutdown)
+                return -ENODEV;
+
         if (!adsp->pcm_path[fe_reg][substream->stream].fe_reg ||
                 !adsp->pcm_path[fe_reg][substream->stream].be_reg) {
                 dev_err(adsp->dev, "Broken Path%d - FE not linked to BE", fe_reg);
@@ -4264,7 +4268,7 @@ static int tegra210_adsp_set_param(struct snd_kcontrol *kcontrol,
         apm_msg_t apm_msg;
         int ret;
 
-        if (!adsp->init_done) {
+        if (!adsp->init_done || adsp->is_shutdown) {
                 dev_warn(adsp->dev, "ADSP is not booted yet\n");
                 return -EPERM;
         }
@@ -4365,7 +4369,7 @@ static int tegra210_adsp_tlv_callback(struct snd_kcontrol *kcontrol,
         unsigned int *tlv_data;
         int ret = 0;
 
-        if (!adsp->init_done) {
+        if (!adsp->init_done || adsp->is_shutdown) {
                 dev_warn(adsp->dev, "ADSP is not booted yet\n");
                 return 0;
         }
@@ -4502,7 +4506,7 @@ static int tegra210_adsp_apm_put(struct snd_kcontrol *kcontrol,
         bool send_msg = 0;
         int ret = 0;
 
-        if (!adsp->init_done) {
+        if (!adsp->init_done || adsp->is_shutdown) {
                 dev_warn(adsp->dev, "ADSP is not booted yet\n");
                 return -EPERM;
         }
@@ -4880,6 +4884,7 @@ static int tegra210_adsp_audio_platform_probe(struct platform_device *pdev)
         }
         dev_set_drvdata(&pdev->dev, adsp);
         adsp->dev = &pdev->dev;
+        adsp->is_shutdown = false;
         adsp->soc_data = (struct adsp_soc_data *)match->data;
 
 
@@ -5175,6 +5180,14 @@ static int __maybe_unused tegra210_adsp_audio_platform_remove(
         return 0;
 }
 
+static void tegra210_adsp_audio_platform_shutdown(
+        struct platform_device *pdev)
+{
+        struct tegra210_adsp *adsp = dev_get_drvdata(&pdev->dev);
+
+        adsp->is_shutdown = true;
+}
+
 static const struct dev_pm_ops tegra210_adsp_pm_ops = {
         SET_RUNTIME_PM_OPS(tegra210_adsp_runtime_suspend,
                            tegra210_adsp_runtime_resume, NULL)
@@ -5189,6 +5202,7 @@ static struct platform_driver tegra210_adsp_audio_driver = {
                 .suppress_bind_attrs = true,
         },
         .probe = tegra210_adsp_audio_platform_probe,
+        .shutdown = tegra210_adsp_audio_platform_shutdown,
         /* TODO enable remove() when the driver is hotpluggable */
         /* .remove = tegra210_adsp_audio_platform_remove, */
 };