On Thu, 08 Dec 2016 11:56:12 +0100, Sutar, Mounesh wrote: > > Hi Takashi, > This is the update I got from Andreas: > > "This is not a generic problem, but can be observed in plugins which use manual linking method. > The plugins such as PLUG, FILE, METER, MULTI and HOOK use manual linkage. > PLUG is the 'bad guy' which might change the linking in hw_param operation. > METER and MULTI might need to be fixed as well. > HOOKS does not use transfer/processing of frames, so seems harmless (but not 100% sure- linkage should be updated for completeness) > > The current fix is provided for FILE plugin ONLY" OK, now I applied the patch as is. The change callback handling would be good if we really have, but let's cover the bug quickly for now. thanks, Takashi > > Regards, > Mounesh > > > -----Original Message----- > From: Takashi Iwai [mailto:tiwai@xxxxxxx] > Sent: 29 November 2016 00:46 > To: sutar.mounesh@xxxxxxxxx > Cc: alsa-devel@xxxxxxxxxxxxxxxx; Sutar, Mounesh <Mounesh_Sutar@xxxxxxxxxx>; Andreas Pape <apape@xxxxxxxxxxxxxx> > Subject: Re: [PATCH] alsa-lib: update linked hw_ptr and appl_ptr > > On Fri, 25 Nov 2016 11:25:05 +0100, > sutar.mounesh@xxxxxxxxx wrote: > > > > From: Andreas Pape <apape@xxxxxxxxxxxxxx> > > > > Plugin file provides no private hw_ptr and appl_ptr but instead links them to the slave pcm. > > If the slave pcm itself changes its hw_ptr or app_prt this needs to be done in file plugin, too. > > Plugin 'plug' is such a candidate changing the hw_ptr and app_ptr in hw_params call dependent on the automatically inserted plugins. > > ALSA unfortunately has no support for automatically updating chained pointers. > > A notification on pointer change seems to be prepared inside the > > snd_pcm_set_ptr() routine via > > rbptr->changed(), but it is not (yet) implemented so that we need to care for it manually. > > > > Signed-off-by: Andreas Pape <apape@xxxxxxxxxxxxxx> > > Judging from the description, isn't it a generic problem, not specific to file plugin? > > > thanks, > > Takashi > > > --- > > src/pcm/pcm_file.c | 8 ++++++++ > > 1 file changed, 8 insertions(+) > > > > diff --git a/src/pcm/pcm_file.c b/src/pcm/pcm_file.c index > > fec76eb..1e3d35b 100644 > > --- a/src/pcm/pcm_file.c > > +++ b/src/pcm/pcm_file.c > > @@ -634,6 +634,14 @@ static int snd_pcm_file_hw_params(snd_pcm_t *pcm, snd_pcm_hw_params_t * params) > > return err; > > } > > } > > + > > + /* pointer may have changed - e.g if plug is used. */ > > + snd_pcm_unlink_hw_ptr(pcm, file->gen.slave); > > + snd_pcm_unlink_appl_ptr(pcm, file->gen.slave); > > + > > + snd_pcm_link_hw_ptr(pcm, file->gen.slave); > > + snd_pcm_link_appl_ptr(pcm, file->gen.slave); > > + > > return 0; > > } > > > > -- > > 1.7.9.5 > > > _______________________________________________ > Alsa-devel mailing list > Alsa-devel@xxxxxxxxxxxxxxxx > http://mailman.alsa-project.org/mailman/listinfo/alsa-devel > _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
