Re: [PATCH] ASoC: SOF: compr: Add compress ops implementation
From: Cezary Rojewski
Date: Fri Jan 14 2022 - 10:50:41 EST
On 2022-01-13 5:13 PM, Daniel Baluta wrote:
From: Daniel Baluta <daniel.baluta@xxxxxxx>
Implement snd_compress_ops. There are a lot of similarities with
PCM implementation.
For now we use sof_ipc_pcm_params to transfer compress parameters to SOF
firmware.
This will be changed in the future once we either add new compress
parameters to SOF or enhance existing sof_ipc_pcm_params structure
to support all native compress params.
Signed-off-by: Daniel Baluta <daniel.baluta@xxxxxxx>
...
+static int create_page_table(struct snd_soc_component *component,
+ struct snd_compr_stream *cstream,
+ unsigned char *dma_area, size_t size)
+{
+ struct snd_soc_pcm_runtime *rtd = cstream->private_data;
+ struct snd_dma_buffer *dmab = cstream->runtime->dma_buffer_p;
+ int dir = cstream->direction;
+ struct snd_sof_pcm *spcm;
The layout of this declaration block is weird - it's neither a
reversed-christmas-tree nor higher->lower complexity (e.g. structs ->
primitives). Could you explain why it is shaped as is?
+
+ spcm = snd_sof_find_spcm_dai(component, rtd);
+ if (!spcm)
+ return -EINVAL;
+
+ return snd_sof_create_page_table(component->dev, dmab,
+ spcm->stream[dir].page_table.area, size);
+}
+
+int sof_compr_open(struct snd_soc_component *component,
+ struct snd_compr_stream *cstream)
+{
+ struct snd_soc_pcm_runtime *rtd = cstream->private_data;
+ struct snd_compr_runtime *runtime = cstream->runtime;
Making use of 'rtd' and 'runtime' simultaneously within a function make
it less readable.
+ struct sof_compr_stream *sstream;
+ struct snd_sof_pcm *spcm;
+ int dir;
+
+ sstream = kzalloc(sizeof(*sstream), GFP_KERNEL);
+ if (!sstream)
+ return -ENOMEM;
+
+ spcm = snd_sof_find_spcm_dai(component, rtd);
+ if (!spcm) {
+ kfree(sstream);
+ return -EINVAL;
+ }
+
+ dir = cstream->direction;
+
+ if (spcm->stream[dir].cstream) {
+ kfree(sstream);
+ return -EBUSY;
+ }
Could you explain why this check is needed? i.e. Is is possible for
compress stream to be opened "twice"?
+
+ spcm->stream[dir].cstream = cstream;
+ spcm->stream[dir].posn.host_posn = 0;
+ spcm->stream[dir].posn.dai_posn = 0;
+ spcm->prepared[dir] = false;
+
+ runtime->private_data = sstream;
+
+ return 0;
+}
+
+int sof_compr_free(struct snd_soc_component *component,
+ struct snd_compr_stream *cstream)
+{
+ struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(component);
+ struct snd_soc_pcm_runtime *rtd = cstream->private_data;
+ struct snd_compr_runtime *runtime = cstream->runtime;
Ditto.
+ struct sof_compr_stream *sstream = runtime->private_data;
+ struct sof_ipc_stream stream;
+ struct sof_ipc_reply reply;
+ struct snd_sof_pcm *spcm;
+ int ret = 0;
+
+ spcm = snd_sof_find_spcm_dai(component, rtd);
+ if (!spcm)
+ return -EINVAL;
+
+ stream.hdr.size = sizeof(stream);
+ stream.hdr.cmd = SOF_IPC_GLB_STREAM_MSG | SOF_IPC_STREAM_PCM_FREE;
+ stream.comp_id = spcm->stream[cstream->direction].comp_id;
+
+ if (spcm->prepared[cstream->direction]) {
+ ret = sof_ipc_tx_message(sdev->ipc, stream.hdr.cmd,
+ &stream, sizeof(stream),
+ &reply, sizeof(reply));
+ if (!ret)
+ spcm->prepared[cstream->direction] = false;
Why is the assignment conditional? If IPC fails, is the ->prepared flag
respected and addressed later on? It does not seem to happen here.
+ }
+
+ cancel_work_sync(&spcm->stream[cstream->direction].period_elapsed_work);
+ spcm->stream[cstream->direction].cstream = NULL;
+ kfree(sstream);
+
+ return ret;
+}
+
+int sof_compr_set_params(struct snd_soc_component *component,
+ struct snd_compr_stream *cstream, struct snd_compr_params *params)
+{
+ struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(component);
+ struct snd_soc_pcm_runtime *rtd_pcm = cstream->private_data;
+ struct snd_compr_runtime *rtd = cstream->runtime;
+ struct sof_compr_stream *sstream = rtd->private_data;
+ struct sof_ipc_pcm_params_reply ipc_params_reply;
+ struct sof_ipc_pcm_params pcm;
+ struct snd_sof_pcm *spcm;
+ int ret;
+
+ spcm = snd_sof_find_spcm_dai(component, rtd_pcm);
+ if (!spcm)
+ return -EINVAL;
+
+ cstream->dma_buffer.dev.type = SNDRV_DMA_TYPE_DEV_SG;
+ cstream->dma_buffer.dev.dev = sdev->dev;
+ ret = snd_compr_malloc_pages(cstream, rtd->buffer_size);
+ if (ret < 0)
+ return ret;
+
+ create_page_table(component, cstream, rtd->dma_area, rtd->dma_bytes);
Shouldn't the result of create_page_table() be tested before moving on?
...
+int sof_compr_trigger(struct snd_soc_component *component,
+ struct snd_compr_stream *cstream, int cmd)
+{
+ struct sof_ipc_stream stream;
+ struct sof_ipc_reply reply;
+ struct snd_soc_pcm_runtime *rtd = cstream->private_data;
+ struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(component);
+ struct snd_sof_pcm *spcm;
Similarly to create_page_table() case, layout of this declaration block
is weird. Perhaps I'm just unaware of the convention used within this
directory.
...
+static int sof_compr_pointer(struct snd_soc_component *component,
+ struct snd_compr_stream *cstream,
+ struct snd_compr_tstamp *tstamp)
+{
+ struct snd_compr_runtime *runtime = cstream->runtime;
+ struct sof_compr_stream *sstream = runtime->private_data;
I'd suggest declaring single local variable instead. The 'runtime' one
is unused except for the initial 'sstream' assignemnt.
+
+ tstamp->sampling_rate = sstream->sample_rate;
+ tstamp->copied_total = sstream->copied_total;
+
+ return 0;
+}
...
diff --git a/sound/soc/sof/sof-priv.h b/sound/soc/sof/sof-priv.h
index 087935192ce8..d001a762a866 100644
--- a/sound/soc/sof/sof-priv.h
+++ b/sound/soc/sof/sof-priv.h
@@ -108,6 +108,12 @@ enum sof_debugfs_access_type {
SOF_DEBUGFS_ACCESS_D0_ONLY,
};
+struct sof_compr_stream {
+ unsigned int copied_total;
+ unsigned int sample_rate;
+ size_t posn_offset;
+};
Some streaming-related PCM structs follow snd_sof_xxx naming pattern
instead, e.g.: snd_sof_pcm. Is the naming convention for compress
streams seen here intentional?
+
struct snd_sof_dev;
struct snd_sof_ipc_msg;
struct snd_sof_ipc;