On 16 November 2017 at 08:59, Shawn Lin <shawn.lin@xxxxxxxxxxxxxx> wrote: > Hi, > > On 2017/11/16 15:47, Ulf Hansson wrote: >> >> On 14 November 2017 at 23:55, Wolfram Sang >> <wsa+renesas@xxxxxxxxxxxxxxxxxxxx> wrote: >>> >>> Documentation/timers/timers-howto.txt recommends to use usleep_range for >>> delays 1-20ms. Let's adhere to it. No need for messing with HZ and still >>> do busy looping these days. >>> > > Sorry for chime in this topic but I think for some cases, for instance, > mmc_host_set_uhs_voltage calls mmc_delay and it should guarantee the > delay is accurate, especially for the comment"Keep clock gated for at > least 10 ms, though spec only says 5 ms" > > But the usleep_range won't guarantee that, see > > https://patchwork.kernel.org/patch/9369963/ > > It wasn't fixed at the end, so you should carefully modify > this fundamentally. git tag --contains 6c5e9059692567740a4ee51530dffe51a4b9584d It should be fixed, however, thanks for pointing to an interesting patch. :-) [...] Kind regards Uffe
