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author | Mark Brown <broonie@kernel.org> | 2022-06-10 17:21:29 +0100 |
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committer | Mark Brown <broonie@kernel.org> | 2022-06-10 17:21:29 +0100 |
commit | 25ebeeebcb5493b42b6d43e4f4c49823782b83af (patch) | |
tree | 927a3e4b74e94c1a9a551345a7a8354133426615 /sound/soc/sof/ipc3-dtrace.c | |
parent | c5d41ca7b2567f55c5448da00cf5013b98ba14db (diff) | |
parent | 1e90de2c9a40d7d0af5c7b0a6e2d362ffba94772 (diff) | |
download | linux-stable-25ebeeebcb5493b42b6d43e4f4c49823782b83af.tar.gz linux-stable-25ebeeebcb5493b42b6d43e4f4c49823782b83af.tar.bz2 linux-stable-25ebeeebcb5493b42b6d43e4f4c49823782b83af.zip |
ASoC: SOF: ipc3-dtrace: Handle race during initialization
Merge series from Peter Ujfalusi <peter.ujfalusi@linux.intel.com>:
This series handles the race which can result missing the first position update
after the trace is enabled.
In short: the firmware might send the position update (if we have enough
trace data generated) after the dma-trace is enabled by the TRACE_DMA_PARAMS_EXT
message. Depending on scheduling, load, preemption on Linux side we have seen
that occasionally this first position update got missed and we missed reading it
out.
A new state and more strict handling of host_offset can overcome this issue,
making the dtrace more reliable.
Diffstat (limited to 'sound/soc/sof/ipc3-dtrace.c')
-rw-r--r-- | sound/soc/sof/ipc3-dtrace.c | 47 |
1 files changed, 38 insertions, 9 deletions
diff --git a/sound/soc/sof/ipc3-dtrace.c b/sound/soc/sof/ipc3-dtrace.c index 45bf9c5dc412..ecca6dceaad2 100644 --- a/sound/soc/sof/ipc3-dtrace.c +++ b/sound/soc/sof/ipc3-dtrace.c @@ -18,6 +18,7 @@ enum sof_dtrace_state { SOF_DTRACE_DISABLED, SOF_DTRACE_STOPPED, + SOF_DTRACE_INITIALIZING, SOF_DTRACE_ENABLED, }; @@ -32,6 +33,15 @@ struct sof_dtrace_priv { enum sof_dtrace_state dtrace_state; }; +static bool trace_pos_update_expected(struct sof_dtrace_priv *priv) +{ + if (priv->dtrace_state == SOF_DTRACE_ENABLED || + priv->dtrace_state == SOF_DTRACE_INITIALIZING) + return true; + + return false; +} + static int trace_filter_append_elem(struct snd_sof_dev *sdev, u32 key, u32 value, struct sof_ipc_trace_filter_elem *elem_list, int capacity, int *counter) @@ -241,6 +251,21 @@ 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) { @@ -273,7 +298,7 @@ static size_t sof_wait_dtrace_avail(struct snd_sof_dev *sdev, loff_t pos, if (ret) return ret; - if (priv->dtrace_state != SOF_DTRACE_ENABLED && priv->dtrace_draining) { + if (priv->dtrace_draining && !trace_pos_update_expected(priv)) { /* * tracing has ended and all traces have been * read by client, return EOF @@ -327,6 +352,10 @@ static ssize_t dfsentry_dtrace_read(struct file *file, char __user *buffer, return -EIO; } + /* no new trace data */ + if (!avail) + return 0; + /* make sure count is <= avail */ if (count > avail) count = avail; @@ -357,7 +386,7 @@ 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; } @@ -433,7 +462,7 @@ 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); @@ -444,6 +473,7 @@ static int ipc3_dtrace_enable(struct snd_sof_dev *sdev) dev_dbg(sdev->dev, "%s: stream_tag: %d\n", __func__, params.stream_tag); /* send IPC to the DSP */ + priv->dtrace_state = SOF_DTRACE_INITIALIZING; ret = sof_ipc_tx_message(sdev->ipc, ¶ms, sizeof(params), &ipc_reply, sizeof(ipc_reply)); if (ret < 0) { dev_err(sdev->dev, "can't set params for DMA for trace %d\n", ret); @@ -451,17 +481,18 @@ static int ipc3_dtrace_enable(struct snd_sof_dev *sdev) } start: + priv->dtrace_state = SOF_DTRACE_ENABLED; + ret = sof_dtrace_host_trigger(sdev, SNDRV_PCM_TRIGGER_START); if (ret < 0) { dev_err(sdev->dev, "Host dtrace trigger start failed: %d\n", ret); goto trace_release; } - priv->dtrace_state = SOF_DTRACE_ENABLED; - return 0; trace_release: + priv->dtrace_state = SOF_DTRACE_DISABLED; sof_dtrace_host_release(sdev); return ret; } @@ -545,11 +576,9 @@ int ipc3_dtrace_posn_update(struct snd_sof_dev *sdev, if (!sdev->fw_trace_is_supported) return 0; - if (priv->dtrace_state == SOF_DTRACE_ENABLED && - priv->host_offset != posn->host_offset) { - priv->host_offset = posn->host_offset; + if (trace_pos_update_expected(priv) && + sof_dtrace_set_host_offset(priv, posn->host_offset)) wake_up(&priv->trace_sleep); - } if (posn->overflow != 0) dev_err(sdev->dev, |