Hi Nicolin, > On Wed, Sep 13, 2017 at 10:02:20AM +0200, Arnaud Mouiche wrote: > > > >Could you please give me a few set of examples of how you set > > >set_sysclk(), set_tdm_slot() with the current driver? The idea > > >here is to figure out a way to calculate the bclk in hw_params > > >without getting set_sysclk() involved any more. > > > Here is one, where a bclk = 4*16*fs is expected > > > In another setup, there are 8 x 16 bits slots, whatever the number > > of active channels is. > > In this case bclk = 128 * fs > > The number of slots is completely arbitrary. Some slots can even be > > reserved for communication between codecs that don't communicate > > with linux. > > In summary, bclk = sample rate * slots * slot_width; > > I will update my patch soon. > > > >Unfortunately, it looks like a work around to me. I understand > > >the idea of leaving set_sysclk() out there to override the bit > > >clock is convenient, but it is not a standard ALSA design and > > >may eventually introduce new problems like today. > > > > I agree. I'm not conservative at all concerning this question. > > I don't see a way to remove set_sysclk without breaking current TDM > > users anyway, at least for those who don't have their code > > upstreamed. > > Which TDM case would be broken by this removal? The only impact > that I can see is that the ASoC core returns an ENOTSUPP for a > set_sysclk() call now, which is something that a dai-link driver > should have taken care of anyway. > > > All information provided through snd_soc_dai_set_tdm_slot( cpu_dai, > > mask, mask, slots, width ) should be enough > > In this case, for TDM users > > > > bclk = slots * width * fs (where slots is != channels) > > > will manage 99 % of the cases. > > And the remaining 1% will concern people who need to hack the kernel > > so widely they don't care about the set_sysclk removal. > > A patch from those people will be always welcome. > > > - fsl-asoc-card.c : *something will break since > > snd_soc_dai_set_sysclk returned code is checked* > > I've already submitted a patch to ignore all ENOTSUPP. Nicolin, do you know what happened with this patch? I couldn't find it in current linux/master. Has it been applied to any asoc tree for being upstreamed? Best regards, Lukasz Majewski -- DENX Software Engineering GmbH, Managing Director: Wolfgang Denk HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd@xxxxxxx
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