From d39789912f150b66515ccda7ed00bba828a334d4 Mon Sep 17 00:00:00 2001
From: Takashi Iwai <tiwai@suse.de>
Date: Tue, 5 Nov 2019 20:10:07 +0100
Subject: [PATCH] ALSA: pcm: Create proc files only for non-empty preallocations
Git-commit: d39789912f150b66515ccda7ed00bba828a334d4
Patch-mainline: v5.5-rc1
References: jsc#SLE-16518

It makes little sense to create prealloc proc files for streams that
have the zero max size, which is a typical case for vmalloc buffers.
Skip the proc file creations to save resources in such a case.

Link: https://lore.kernel.org/r/20191105191007.18150-3-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

---
 sound/core/pcm_memory.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/sound/core/pcm_memory.c b/sound/core/pcm_memory.c
index 19407f79b638..17ee361ce791 100644
--- a/sound/core/pcm_memory.c
+++ b/sound/core/pcm_memory.c
@@ -203,7 +203,8 @@ static void snd_pcm_lib_preallocate_pages1(struct snd_pcm_substream *substream,
 	if (substream->dma_buffer.bytes > 0)
 		substream->buffer_bytes_max = substream->dma_buffer.bytes;
 	substream->dma_max = max;
-	preallocate_info_init(substream);
+	if (max > 0)
+		preallocate_info_init(substream);
 }
 
 
-- 
2.16.4