Re: [PATCH] mmc: core: Restore (almost) the busy polling for MMC_SEND_OP_COND

From: H. Nikolaus Schaller
Date: Fri Mar 04 2022 - 09:39:03 EST


Hi Ulf,

> Am 04.03.2022 um 11:56 schrieb Ulf Hansson <ulf.hansson@xxxxxxxxxx>:
>
> Commit 76bfc7ccc2fa ("mmc: core: adjust polling interval for CMD1"),
> significantly decreased the polling period from ~10-12ms into just a couple
> of us. The purpose was to decrease the total time spent in the busy polling
> loop, but unfortunate it has lead to problems, that causes eMMC cards to
> never gets out busy and thus fails to be initialized.
>
> To fix the problem, but also to try to keep some of the new improved
> behaviour, let's start by using a polling period of 1-2ms, which then
> increases for each loop, according to common polling loop in
> __mmc_poll_for_busy().
>
> Reported-by: Jean Rene Dawin <jdawin@xxxxxxxxxxxxxxxxxxxxx>
> Reported-by: H. Nikolaus Schaller <hns@xxxxxxxxxxxxx>
> Cc: Huijin Park <huijin.park@xxxxxxxxxxx>
> Fixes: 76bfc7ccc2fa ("mmc: core: adjust polling interval for CMD1")
> Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
> ---
>
> Jean Rene and H. Nikolaus, if this doesn't work, please try extending the
> the MMC_OP_COND_PERIOD_US a bit, to so see if we can find a value that always
> works.

Works for me.

BR and thanks,
Nikolaus