On Mon, Oct 21, 2024 at 10:31 PM David Lechner <dlechner@xxxxxxxxxxxx> wrote: > > On 10/21/24 2:03 PM, David Lechner wrote: > > On 10/21/24 8:02 AM, Alexandru Ardelean wrote: > >> There's a small issue with setting oversampling-ratio that seems to have > >> been there since the driver was in staging. > >> Trying to set an oversampling value of '2' will set an oversampling value > >> of '1'. This is because find_closest() does an average + rounding of 1 + 2, > >> and we get '1'. > >> > >> This is the only issue with find_closest(), at least in this setup. The > >> other values (above 2) work reasonably well. Setting 3, rounds to 2, so a > >> quick fix is to round 'val' to 3 (if userspace provides 2). > > > > This sounds like a bug in find_closest() instead of in this driver. > > Adding Bart (the original author of find_closest()). > > If there is an exact match in the list, it seems reasonable to expect > > that the exact match is returned by find_closest(). > > > > Likely also affected by this bug since they have values 1, 2 in the list: > > * rtq6056_adc_set_average() > * si1133_scale_to_swgain() Yeah. I forgot to mention this sooner. But this patch is more of an RFC patch about how to handle this situation with find_closest(). For monotonic values with an increment of 1, find_closest() is a bit buggy. Will try to fix find_closest() >
