Re: [PATCH 4.19 215/219] mmc: sdhci: Update the tuning failed messages to pr_debug level

From: Pavel Machek
Date: Tue Dec 31 2019 - 06:02:47 EST


On Sun 2019-12-29 18:20:17, Greg Kroah-Hartman wrote:
> From: Faiz Abbas <faiz_abbas@xxxxxx>
>
> commit 2c92dd20304f505b6ef43d206fff21bda8f1f0ae upstream.
>
> Tuning support in DDR50 speed mode was added in SD Specifications Part1
> Physical Layer Specification v3.01. Its not possible to distinguish
> between v3.00 and v3.01 from the SCR and that is why since
> commit 4324f6de6d2e ("mmc: core: enable CMD19 tuning for DDR50 mode")
> tuning failures are ignored in DDR50 speed mode.
>
> Cards compatible with v3.00 don't respond to CMD19 in DDR50 and this
> error gets printed during enumeration and also if retune is triggered at
> any time during operation. Update the printk level to pr_debug so that
> these errors don't lead to false error reports.

Well, downgrading level might be ok, but people will still see the
message in dmesg.

> +++ b/drivers/mmc/host/sdhci.c
> @@ -2244,8 +2244,8 @@ static void __sdhci_execute_tuning(struc
> sdhci_send_tuning(host, opcode);
>
> if (!host->tuning_done) {
> - pr_info("%s: Tuning timeout, falling back to fixed sampling clock\n",
> - mmc_hostname(host->mmc));
> + pr_debug("%s: Tuning timeout, falling back to fixed sampling clock\n",
> + mmc_hostname(host->mmc));

Maybe adding something like "(this is expected on SD cards
implementing phy specification v3.00)" to the user-visible text would
be even better?

Best regards,
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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