Hi Mark, > On Mon, Jun 06, 2022 at 05:44:40PM +0200, Lukasz Majewski wrote: > > Without this change, the wm8940 driver is not working when > > set_sysclk callback (wm8940_set_dai_sysclk) is called with > > freqency not listed in the switch clause. > > > This change adjusts this driver to allow non-standard frequency > > set (just after the boot) being adjusted afterwards by the sound > > system core code. > > I don't entirely follow the above - in what way might the core adjust > the clocking, and why would we want to allow the use of invalid > clocks? Surely that just makes error checking worse. Hmm, it is a bit complicated. When I enabed wm8940 support in mainline - the first call to wm8940_set_dai_sysclk (the set_sysclk callback) required mclk = 11997070 frequency. With the current code [1] the initialization of the codec returns -EINVAL and the codec is not supported in the system: asoc-simple-card: probe of sound failed with error -22 The approach used in this patch set to fix the above issue is based on one already present in-tree for wm8974 codec. > > > Code in this commit is based on previous change done for wm8974 > > (SHA1: 51b2bb3f2568e6d9d81a001d38b8d70c2ba4af99). > > Please include human readable descriptions of things like commits and > issues being discussed in e-mail in your mails, this makes them much > easier for humans to read especially when they have no internet > access. Ok, I will add some more verbose description. The aforementioned SHA1 is referring to commit already in-tree, so you would find it easily even without the Internet. > I do frequently catch up on my mail on flights or while > otherwise travelling so this is even more pressing for me than just > being about making things a bit easier to read. +1 Links: [1] - https://elixir.bootlin.com/linux/v5.18.1/source/sound/soc/codecs/wm8940.c#L614 Best regards, Lukasz Majewski -- DENX Software Engineering GmbH, Managing Director: Wolfgang Denk HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-59 Fax: (+49)-8142-66989-80 Email: lukma@xxxxxxx
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