On Wed, 23 Feb 2022 17:32:19 +0100, Mark Brown wrote: > > On Wed, Feb 23, 2022 at 03:55:54PM +0100, Takashi Iwai wrote: > > > > But, more reading the code, I suspect whether the function does work > > correctly at all... How is the mask calculation done in that way? > > unsigned int mask = (1U << (fls(min + max) - 1)) - 1; > > What's the difference of this function with snd_soc_put_volsw()? > > Yeah, I'm not clear either - Marek mentioned _SX when he was doing the > patch but I didn't get the bandwidth to figure out what it's doing > properly yet. At this point I'm not clear what _SX is supposed to do, > I'm hoping it works well for the devices that use it but I don't have > any of them. OK, let's hope that... > > Furthermore, the mask calculation and usage in snd_soc_put_volsw() > > isn't right, either, I'm afraid; if the range is [-10, 0], max=0, then > > mask will 0, which will omit all values... > > Indeed, if anyone did that. Fortunately I don't *think* that's an > issue. The whole way that code handles signed bitfields by remapping > them into unsigned user visible controls is a landmine, it's not even > obvious that they handle signed bitfields in the first place. Thanks, then it seems OK as is for now. I guess the signed bit should be detected by the helper instead of hard-coding, but it's no urgent issue. Takashi
