[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: Jaroslav Kysela <perex@suse.cz>

[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: Jaroslav Kysela <perex@suse.cz>
Jaroslav Kysela
1 parent b66b3cfe6c
Showing 2 changed files with 24 additions and 0 deletions Side-by-side Diff
include/sound/pcm.h
sound/core/pcm_memory.c
@@ -384,6 +384,7 @@
 	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;
@@ -101,6 +101,8 @@
 {
 	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
@@ -142,6 +144,18 @@
 }
  
 /*
+ * 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
  *
  * accepts the preallocation size in kB.
@@ -203,6 +217,15 @@
 		}
 	}
 	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 */
...	...	@@ -384,6 +384,7 @@
384	384	struct snd_info_entry *proc_sw_params_entry;
385	385	struct snd_info_entry *proc_status_entry;
386	386	struct snd_info_entry *proc_prealloc_entry;
	387	+ struct snd_info_entry *proc_prealloc_max_entry;
387	388	#endif
388	389	/* misc flags */
389	390	unsigned int hw_opened: 1;
...	...	@@ -101,6 +101,8 @@
101	101	{
102	102	snd_pcm_lib_preallocate_dma_free(substream);
103	103	#ifdef CONFIG_SND_VERBOSE_PROCFS
	104	+ snd_info_free_entry(substream->proc_prealloc_max_entry);
	105	+ substream->proc_prealloc_max_entry = NULL;
104	106	snd_info_free_entry(substream->proc_prealloc_entry);
105	107	substream->proc_prealloc_entry = NULL;
106	108	#endif
...	...	@@ -142,6 +144,18 @@
142	144	}
143	145
144	146	/*
	147	+ * read callback for prealloc_max proc file
	148	+ *
	149	+ * prints the maximum allowed size in kB.
	150	+ */
	151	+static void snd_pcm_lib_preallocate_max_proc_read(struct snd_info_entry *entry,
	152	+ struct snd_info_buffer *buffer)
	153	+{
	154	+ struct snd_pcm_substream *substream = entry->private_data;
	155	+ snd_iprintf(buffer, "%lu\n", (unsigned long) substream->dma_max / 1024);
	156	+}
	157	+
	158	+/*
145	159	* write callback for prealloc proc file
146	160	*
147	161	* accepts the preallocation size in kB.
...	...	@@ -203,6 +217,15 @@
203	217	}
204	218	}
205	219	substream->proc_prealloc_entry = entry;
	220	+ if ((entry = snd_info_create_card_entry(substream->pcm->card, "prealloc_max", substream->proc_root)) != NULL) {
	221	+ entry->c.text.read = snd_pcm_lib_preallocate_max_proc_read;
	222	+ entry->private_data = substream;
	223	+ if (snd_info_register(entry) < 0) {
	224	+ snd_info_free_entry(entry);
	225	+ entry = NULL;
	226	+ }
	227	+ }
	228	+ substream->proc_prealloc_max_entry = entry;
206	229	}
207	230
208	231	#else /* !CONFIG_SND_VERBOSE_PROCFS */