On Tue, Jun 13, 2023 at 06:15:12PM +0200, Takashi Iwai wrote: > Mark Brown wrote: > > On Tue, Jun 13, 2023 at 04:24:28PM +0200, Takashi Iwai wrote: > > > Since HD-audio codec has no known default values unlike normal codecs, > > > it needs to initialize itself only at the first access, and this > > > helper does it. > > Ah, if it's just suppressing the write the code should just be removed. > > regmap_update_bits() already suppresses noop writes so unless we might > > write a different value to the register later the effect will be the > > same. I can send a patch. > Oh, I'm afraid that we're seeing different things. The code there is > rather to *set* some initial value for each amp register (but only > once), and it's not about optimization for writing a same value > again. > That is, the function helps to set an initial (mute) value on each amp > when the driver parses the topology and finds an amp. But if the > driver already has parsed this amp beforehand by other paths, it skips > the initialization, as the other path may have already unmuted the > amp. > Or I might have misunderstood what you mean about _update_bits()... So it is possible that we might set two distinct values during setup then and we're doing this intentionally? It's not obvious that this might happen. A comment wouldn't hurt, and a big part of this is confusing is that in the non-regmap case all we're doing is suppressing duplicate writes, in that path it's just checking for changes in the register value. None of this is what the non-regmap path does, it just suppresses noop writes to the hardware.
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