[PATCH alsa-lib 1/2] pcm_hw: Remove unused fields in struct

[PATCH alsa-lib 1/2] pcm_hw: Remove unused fields in struct

[David Henningsson]

These fields are not used, and their name similarity to other
fields are quite confusing when trying to debug alsa-lib.

Signed-off-by: David Henningsson <david.henningsson@canonical.com>
---
 src/pcm/pcm_hw.c |    2 --
 1 file changed, 2 deletions(-)

diff --git a/src/pcm/pcm_hw.c b/src/pcm/pcm_hw.c
index 0f3226d..196393d 100644
--- a/src/pcm/pcm_hw.c
+++ b/src/pcm/pcm_hw.c
@@ -95,8 +95,6 @@ typedef struct {
 	volatile struct snd_pcm_mmap_status * mmap_status;
 	struct snd_pcm_mmap_control *mmap_control;
 	struct snd_pcm_sync_ptr *sync_ptr;
-	snd_pcm_uframes_t hw_ptr;
-	snd_pcm_uframes_t appl_ptr;
 	int period_event;
 	snd_timer_t *period_timer;
 	struct pollfd period_timer_pfd;
-- 
1.7.9.5

[PATCH alsa-lib 2/2] pcm_plugin: Fix return value of snd_pcm_rewind

[David Henningsson]

In case the rewind did not rewind as much as expected, e g due to
time delay between the latest avail update and the rewind, we must
properly account for that in the plugin layer.

Otherwise, the plugin's appl ptr and the hw's appl ptr become
unsynchronised, which is very bad, especially in mmap_shadow plugins,
e g, this could cause the overlapping memcpy in the softvol plugin
as seen here:
https://bugs.freedesktop.org/show_bug.cgi?id=64299

Signed-off-by: David Henningsson <david.henningsson@canonical.com>
---
 src/pcm/pcm_plugin.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Btw, I was also considering always syncing the appl.ptr (for playback)
with the slave in snd_pcm_plugin_avail_update, like we do for the
hw.ptr. Do you think this would be a good idea?

diff --git a/src/pcm/pcm_plugin.c b/src/pcm/pcm_plugin.c
index 96218a8..17157e8 100644
--- a/src/pcm/pcm_plugin.c
+++ b/src/pcm/pcm_plugin.c
@@ -219,9 +219,9 @@ static snd_pcm_sframes_t snd_pcm_plugin_rewind(snd_pcm_t *pcm, snd_pcm_uframes_t
 		snd_atomic_write_end(&plugin->watom);
 		return sframes;
 	}
-	snd_pcm_mmap_appl_backward(pcm, (snd_pcm_uframes_t) frames);
+	snd_pcm_mmap_appl_backward(pcm, (snd_pcm_uframes_t) sframes);
 	snd_atomic_write_end(&plugin->watom);
-	return (snd_pcm_sframes_t) frames;
+	return (snd_pcm_sframes_t) sframes;
 }
 
 static snd_pcm_sframes_t snd_pcm_plugin_forwardable(snd_pcm_t *pcm)
-- 
1.7.9.5

Re: [PATCH alsa-lib 2/2] pcm_plugin: Fix return value of snd_pcm_rewind

[Jaroslav Kysela]

Date 30.5.2013 12:26, David Henningsson wrote:
> In case the rewind did not rewind as much as expected, e g due to
> time delay between the latest avail update and the rewind, we must
> properly account for that in the plugin layer.

Thank you very much for this fix.
I applied both patches to alsa-lib's repo.

				Jaroslav

-- 
Jaroslav Kysela <perex@perex.cz>
Linux Kernel Sound Maintainer
ALSA Project; Red Hat, Inc.

Re: [PATCH alsa-lib 2/2] pcm_plugin: Fix return value of snd_pcm_rewind

[Arun Raghavan]

On Thu, 2013-05-30 at 14:05 +0200, Jaroslav Kysela wrote:
> Date 30.5.2013 12:26, David Henningsson wrote:
> > In case the rewind did not rewind as much as expected, e g due to
> > time delay between the latest avail update and the rewind, we must
> > properly account for that in the plugin layer.
> 
> Thank you very much for this fix.
> I applied both patches to alsa-lib's repo.

Could we get a release with these patches? This does bite people a bit.

-- Arun

Re: [PATCH alsa-lib 2/2] pcm_plugin: Fix return value of snd_pcm_rewind

[Jaroslav Kysela]

Date 26.6.2013 08:36, Arun Raghavan wrote:
> On Thu, 2013-05-30 at 14:05 +0200, Jaroslav Kysela wrote:
>> Date 30.5.2013 12:26, David Henningsson wrote:
>>> In case the rewind did not rewind as much as expected, e g due to
>>> time delay between the latest avail update and the rewind, we must
>>> properly account for that in the plugin layer.
>>
>> Thank you very much for this fix.
>> I applied both patches to alsa-lib's repo.
> 
> Could we get a release with these patches? This does bite people a bit.

I'll try to prepare alsa-lib 1.0.27.2 package in a few hours.

				Jaroslav

-- 
Jaroslav Kysela <perex@perex.cz>
Linux Kernel Sound Maintainer
ALSA Project; Red Hat, Inc.