Messages in this thread | | | From | "Hebbar, Gururaja" <> | Subject | RE: [alsa-devel] [PATCH] ALSA: ASoC: McASP: Fix data rotation for playback. Enables 24bit audio playback | Date | Fri, 18 Jan 2013 08:48:36 +0000 |
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On Fri, Jan 18, 2013 at 14:13:40, Michal Bachraty wrote: > On Friday, January 18, 2013 08:22:53 Hebbar, Gururaja wrote: > > On Tue, Jan 15, 2013 at 20:11:00, Michal Bachraty wrote: > > > Signed-off-by: Michal Bachraty <michal.bachraty@streamunlimited.com> > > > > Even simple patches need a simple changelog. > > Add a brief description about what & why it is done? > > > > Hi Gurujaja, > > > > - u32 rotate = (32 - word_length) / 4; > This implementation is wrong, but it works only for 16, or 32 bit audio data. > (rotation for 16 or 32 bit is same as in code I present) Mcasp rotated data in > 4 bits (max value 0x7)and then masks them . That data are sended to i2s bus. > For 24 bit or 20 bit or other data formats, this code rotates data badly and > you hear somethink like noise. You need to use > > > + u32 rotate = (word_length / 4) & 0x7; > to proper data rotation.
Correct. Now can you add the above info into the patch and re-submit. That way when users sees this patch, they will get all the info needed.
> > Regards, > Michal > >
Regards, Gururaja
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