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Subject: Re: [PATCH] mmc: core: Restore (almost) the busy polling for
 MMC_SEND_OP_COND
From:   "H. Nikolaus Schaller" <hns@goldelico.com>
In-Reply-To: <20220304105656.149281-1-ulf.hansson@linaro.org>
Date:   Fri, 4 Mar 2022 15:38:45 +0100
Cc:     linux-mmc@vger.kernel.org,
        Jean Rene Dawin <jdawin@math.uni-bielefeld.de>,
        Huijin Park <huijin.park@samsung.com>,
        linux-kernel@vger.kernel.org
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Message-Id: <EE1CAC2A-C06C-4E1F-A391-A063972A34A2@goldelico.com>
References: <20220304105656.149281-1-ulf.hansson@linaro.org>
To:     Ulf Hansson <ulf.hansson@linaro.org>
Precedence: bulk

Hi Ulf,

> Am 04.03.2022 um 11:56 schrieb Ulf Hansson <ulf.hansson@linaro.org>:
>=20
> 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.
>=20
> 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().
>=20
> Reported-by: Jean Rene Dawin <jdawin@math.uni-bielefeld.de>
> Reported-by: H. Nikolaus Schaller <hns@goldelico.com>
> Cc: Huijin Park <huijin.park@samsung.com>
> Fixes: 76bfc7ccc2fa ("mmc: core: adjust polling interval for CMD1")
> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
> ---
>=20
> 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