File alsa-lib-pcm-plug-mmap-fix.diff of Package alsa

From d3a8e853fb0780ecf85b54eba0926698970b3934 Mon Sep 17 00:00:00 2001
From: Takashi Iwai <tiwai@suse.de>
Date: Tue, 27 Jan 2009 17:21:34 +0100
Subject: [PATCH] Fix plug conversion with mmap emulation

If the slave PCM supports only another type of interleaved format,
plug did convert it wrongly and resulted in an unused access type
error.  For example, if a slave PCM supporst only RW_NONINTERLEAVE
access and you try to play an interleaved format file, it resulted
in an error.

This patch fixes the conversion rule.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
 src/pcm/pcm_plug.c |   33 +++++++++++++++++++++++++--------
 1 files changed, 25 insertions(+), 8 deletions(-)

diff --git a/src/pcm/pcm_plug.c b/src/pcm/pcm_plug.c
index abd3d43..09028c9 100644
--- a/src/pcm/pcm_plug.c
+++ b/src/pcm/pcm_plug.c
@@ -605,7 +605,14 @@ static int snd_pcm_plug_change_mmap(snd_pcm_t *pcm, snd_pcm_t **new,
 				       plug->gen.slave != plug->req_slave);
 	if (err < 0)
 		return err;
-	slv->access = clt->access;
+	switch (slv->access) {
+	case SND_PCM_ACCESS_RW_INTERLEAVED:
+		slv->access = SND_PCM_ACCESS_MMAP_INTERLEAVED;
+		break;
+	case SND_PCM_ACCESS_RW_NONINTERLEAVED:
+		slv->access = SND_PCM_ACCESS_MMAP_NONINTERLEAVED;
+		break;
+	}
 	return 1;
 }
 #endif
@@ -743,19 +750,29 @@ static int check_access_change(snd_pcm_hw_params_t *cparams,
 		return 0; /* OK, we have mmap support */
 #ifdef BUILD_PCM_PLUGIN_MMAP_EMUL
 	/* no mmap support - we need mmap emulation */
+
+	if (!snd_pcm_access_mask_test(smask, SND_PCM_ACCESS_RW_INTERLEAVED) &&
+	    !snd_pcm_access_mask_test(smask, SND_PCM_ACCESS_RW_NONINTERLEAVED)) 
+		return -EINVAL; /* even no RW access?  no way! */
+
 	cmask = (const snd_pcm_access_mask_t *)
 		snd_pcm_hw_param_get_mask(cparams,
 					  SND_PCM_HW_PARAM_ACCESS);
 	snd_mask_none(&mask);
 	if (snd_pcm_access_mask_test(cmask, SND_PCM_ACCESS_RW_INTERLEAVED) ||
-	    snd_pcm_access_mask_test(cmask, SND_PCM_ACCESS_MMAP_INTERLEAVED))
-		snd_pcm_access_mask_set(&mask,
-					SND_PCM_ACCESS_RW_INTERLEAVED);
+	    snd_pcm_access_mask_test(cmask, SND_PCM_ACCESS_MMAP_INTERLEAVED)) {
+		if (snd_pcm_access_mask_test(smask, SND_PCM_ACCESS_RW_INTERLEAVED))
+			snd_pcm_access_mask_set(&mask,
+						SND_PCM_ACCESS_RW_INTERLEAVED);
+	}
 	if (snd_pcm_access_mask_test(cmask, SND_PCM_ACCESS_RW_NONINTERLEAVED) ||
-	    snd_pcm_access_mask_test(cmask, SND_PCM_ACCESS_MMAP_NONINTERLEAVED))
-		snd_pcm_access_mask_set(&mask,
-					SND_PCM_ACCESS_RW_NONINTERLEAVED);
-	*smask = mask;
+	    snd_pcm_access_mask_test(cmask, SND_PCM_ACCESS_MMAP_NONINTERLEAVED)) {
+		if (snd_pcm_access_mask_test(smask, SND_PCM_ACCESS_RW_NONINTERLEAVED))
+			snd_pcm_access_mask_set(&mask,
+						SND_PCM_ACCESS_RW_NONINTERLEAVED);
+	}
+	if (!snd_mask_empty(&mask))
+		*smask = mask; /* prefer the straight conversion */
 	return 0;
 #else
 	return -EINVAL;
-- 
1.6.1.3