Re: [PATCH RFT] mmc: core: use usleep_range rather than HZ magic in mmc_delay()

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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
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