On Fri, Aug 14, 2020 at 10:33 AM Crt Mori <cmo@xxxxxxxxxxx> wrote: > On Thu, 13 Aug 2020 at 21:41, Andy Shevchenko <andy.shevchenko@xxxxxxxxx> wrote: > > On Thu, Aug 13, 2020 at 4:04 PM Crt Mori <cmo@xxxxxxxxxxx> wrote: > > > On Thu, 13 Aug 2020 at 13:24, Andy Shevchenko <andy.shevchenko@xxxxxxxxx> wrote: > > > > On Thu, Aug 13, 2020 at 2:14 PM Crt Mori <cmo@xxxxxxxxxxx> wrote: > > > > > On Thu, 13 Aug 2020 at 13:03, Andy Shevchenko <andy.shevchenko@xxxxxxxxx> wrote: > > > > > > On Thu, Aug 13, 2020 at 10:53 AM Crt Mori <cmo@xxxxxxxxxxx> wrote: > > > > ... > > > > > > > > I don't see how it prevents using iopoll.h. It uses usleep_range() > > > > > > under the hood in the same way you did here, but open coded. > > > > > > > > > > > > > > > > One loop is indeed 10ms and that is not the problem, the problem is > > > > > that timeout is at least 3 calls of this data ready (3 channels), so > > > > > that is at minimum 30ms of timeout, or it could even be 4 in worse > > > > > case scenario and that is outside of the range for usleep to measure. > > > > > So in case of the other loop, where we wait 200ms for channel refresh > > > > > it is also out of scope. Timeout should be in number of tries or in > > > > > msleep range if you ask me. > > > > > > > > I still didn't buy it. You have in both cases usleep_range(). Why in > > > > your case it's okay and in regmap_read_poll_timeout() is not? > > > > > > > > > > I tried and it did not work, so then I read the manual. Looking into > > > > > > * regmap_read_poll_timeout_atomic - Poll until a condition is met or a > > > timeout occurs > > > > Why _atomic?! > > I just pasted something, it is the same as for non _atomic OK. ... > > > * @delay_us: Time to udelay between reads in us (0 tight-loops). > > > * Should be less than ~10us since udelay is used > > > * (see Documentation/timers/timers-howto.rst). > > > * @timeout_us: Timeout in us, 0 means never timeout ... > > > > > > > usleep_range(10000, 11000); > > > > You use here usleep_range(). The same is used for > > regmap_read_poll_timeout(). What's the difference? > > > > Since it uses 1/4 of the range you probably need to update tries and > > timeout_us to make it work. > > > > Timeout_us here needs to be in one case 100 * 10ms (maybe not > realistic as we could live with number of around 40 * 10ms), but this > is a lot more than proposed range of usleep which Is up to 20ms. Even > in best case this timeout should be 40 ms to give enough time to > measure 2 channels for sure. So with the current timeout_us > requirement we are outside of the range of the udelay timer and that > is why I would need a macro with number of tries, not with the timeout > value (or timeout value of ms). I do not understand. The regmap_read_poll_timeout() is a macro which unrolls in the very similar loop you have now in the code. What prevents it from using it? I think there is a big misunderstanding about the parameters of that macro. delay_us (must be small enough), timeout_us can be any long. -- With Best Regards, Andy Shevchenko
