Commit c7132aeb authored by Jaroslav Kysela's avatar Jaroslav Kysela
Browse files

[ALSA] pcm core: add prealloc_max file to substream directory to show maximum DMA size 



Users ask us many times about the maximum DMA size for PCM devices. This
file gives them a hint in KB.

Signed-off-by: default avatarJaroslav Kysela <perex@suse.cz>
parent b66b3cfe

include/sound/pcm.h

+1 −0
Original line number Diff line number Diff line
@@ -384,6 +384,7 @@ struct snd_pcm_substream { 
	struct snd_info_entry *proc_sw_params_entry;

	struct snd_info_entry *proc_status_entry;

	struct snd_info_entry *proc_prealloc_entry;

	struct snd_info_entry *proc_prealloc_max_entry;

#endif

	/* misc flags */

	unsigned int hw_opened: 1;

sound/core/pcm_memory.c

+23 −0
Original line number Diff line number Diff line
@@ -101,6 +101,8 @@ int snd_pcm_lib_preallocate_free(struct snd_pcm_substream *substream) 
{

	snd_pcm_lib_preallocate_dma_free(substream);

#ifdef CONFIG_SND_VERBOSE_PROCFS

	snd_info_free_entry(substream->proc_prealloc_max_entry);

	substream->proc_prealloc_max_entry = NULL;

	snd_info_free_entry(substream->proc_prealloc_entry);

	substream->proc_prealloc_entry = NULL;

#endif
@@ -141,6 +143,18 @@ static void snd_pcm_lib_preallocate_proc_read(struct snd_info_entry *entry, 
	snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_buffer.bytes / 1024);

}



/*

 * read callback for prealloc_max proc file

 *

 * prints the maximum allowed size in kB.

 */

static void snd_pcm_lib_preallocate_max_proc_read(struct snd_info_entry *entry,

						  struct snd_info_buffer *buffer)

{

	struct snd_pcm_substream *substream = entry->private_data;

	snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_max / 1024);

}



/*

 * write callback for prealloc proc file

 *
@@ -203,6 +217,15 @@ static inline void preallocate_info_init(struct snd_pcm_substream *substream) 
		}

	}

	substream->proc_prealloc_entry = entry;

	if ((entry = snd_info_create_card_entry(substream->pcm->card, "prealloc_max", substream->proc_root)) != NULL) {

		entry->c.text.read = snd_pcm_lib_preallocate_max_proc_read;

		entry->private_data = substream;

		if (snd_info_register(entry) < 0) {

			snd_info_free_entry(entry);

			entry = NULL;

		}

	}

	substream->proc_prealloc_max_entry = entry;

}



#else /* !CONFIG_SND_VERBOSE_PROCFS */