diff options
| author | Peter Ujfalusi <peter.ujfalusi@linux.intel.com> | 2022-06-10 11:01:18 +0300 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2022-06-10 15:31:46 +0300 |
| commit | b66f9e703f0bee4e1aa7010299914b7b2009b4e0 (patch) | |
| tree | a128cd27136d1528dbb42c3783a25ce15cd7959a /sound/soc/sof/ipc3-dtrace.c | |
| parent | 135786c32ed057068bec56f67a54064cfc845bde (diff) | |
| download | linux-b66f9e703f0bee4e1aa7010299914b7b2009b4e0.tar.xz | |
ASoC: SOF: ipc3-dtrace: Add helper function to update the sdev->host_offset
We are using the READ_ONCE() on the debugfs read path for accessing
sdev->host_offset, but the set is not atomic or protected in any way.
Add a small helper to do the host_offset update and be really paranoid
about the a possible race in update
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20220610080119.30880-3-peter.ujfalusi@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'sound/soc/sof/ipc3-dtrace.c')
| -rw-r--r-- | sound/soc/sof/ipc3-dtrace.c | 23 |
1 files changed, 18 insertions, 5 deletions
diff --git a/sound/soc/sof/ipc3-dtrace.c b/sound/soc/sof/ipc3-dtrace.c index 9292ff7ce1e8..1f4d7a98c8fc 100644 --- a/sound/soc/sof/ipc3-dtrace.c +++ b/sound/soc/sof/ipc3-dtrace.c @@ -252,6 +252,21 @@ static int debugfs_create_trace_filter(struct snd_sof_dev *sdev) return 0; } +static bool sof_dtrace_set_host_offset(struct sof_dtrace_priv *priv, u32 new_offset) +{ + u32 host_offset = READ_ONCE(priv->host_offset); + + if (host_offset != new_offset) { + /* This is a bit paranoid and unlikely that it is needed */ + u32 ret = cmpxchg(&priv->host_offset, host_offset, new_offset); + + if (ret == host_offset) + return true; + } + + return false; +} + static size_t sof_dtrace_avail(struct snd_sof_dev *sdev, loff_t pos, size_t buffer_size) { @@ -368,7 +383,7 @@ static int dfsentry_dtrace_release(struct inode *inode, struct file *file) /* avoid duplicate traces at next open */ if (priv->dtrace_state != SOF_DTRACE_ENABLED) - priv->host_offset = 0; + sof_dtrace_set_host_offset(priv, 0); return 0; } @@ -444,7 +459,7 @@ static int ipc3_dtrace_enable(struct snd_sof_dev *sdev) params.buffer.pages = priv->dma_trace_pages; params.stream_tag = 0; - priv->host_offset = 0; + sof_dtrace_set_host_offset(priv, 0); priv->dtrace_draining = false; ret = sof_dtrace_host_init(sdev, &priv->dmatb, ¶ms); @@ -559,10 +574,8 @@ int ipc3_dtrace_posn_update(struct snd_sof_dev *sdev, return 0; if (trace_pos_update_expected(priv) && - priv->host_offset != posn->host_offset) { - priv->host_offset = posn->host_offset; + sof_dtrace_set_host_offset(priv, posn->host_offset)) wake_up(&priv->trace_sleep); - } if (posn->overflow != 0) dev_err(sdev->dev, |