ALSA: memalloc: Make SG-buffer helper usable for continuous buffer, too
We have a few helper functions for making the access to the buffer
address easier on SG-buffer. Those are specific to the buffer that is
allocated with SG-buffer type, and it makes hard to use both SG and
non-SG buffers in the same code.
This patch adds a few simple checks and lets the helpers to deal with
both SG- and continuous buffers gracefully. It's a preliminary step
for the upcoming patch that mimics the buffer type on the fly.
Link: https://lore.kernel.org/r/20200615160045.2703-4-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/core/sgbuf.c b/sound/core/sgbuf.c
index c42217e..29ddb76 100644
--- a/sound/core/sgbuf.c
+++ b/sound/core/sgbuf.c
@@ -142,6 +142,9 @@ unsigned int snd_sgbuf_get_chunk_size(struct snd_dma_buffer *dmab,
struct snd_sg_buf *sg = dmab->private_data;
unsigned int start, end, pg;
+ if (!sg)
+ return size;
+
start = ofs >> PAGE_SHIFT;
end = (ofs + size - 1) >> PAGE_SHIFT;
/* check page continuity */
