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References: <c207948f590d4e88945a314bf8299f87@hyperstone.com> <aac0cdefbd2a43329b50a803b7c46959@hyperstone.com>
In-Reply-To: <aac0cdefbd2a43329b50a803b7c46959@hyperstone.com>
From:   Ulf Hansson <ulf.hansson@linaro.org>
Date:   Mon, 20 Dec 2021 11:27:21 +0100
Message-ID: <CAPDyKFpoAwezgThhhWgApvfq0nfZFPV4mCJOWGF4ZFp27UhekA@mail.gmail.com>
Subject: Re: [PATCH] mmc: bus: Log bus width info when attaching card
To:     =?UTF-8?Q?Christian_L=C3=B6hle?= <CLoehle@hyperstone.com>
Cc:     "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "linux-mmc@vger.kernel.org" <linux-mmc@vger.kernel.org>,
        "johan@kernel.org" <johan@kernel.org>,
        "sudeep.holla@arm.com" <sudeep.holla@arm.com>,
        "linux@dominikbrodowski.net" <linux@dominikbrodowski.net>
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On Wed, 8 Dec 2021 at 14:03, Christian L=C3=B6hle <CLoehle@hyperstone.com> =
wrote:
>
> Might seem unecessary to print the bus width and a bit confusing, but it =
is the only 'bus info' that is not printed in that line.
> So I suggest adding it.

Well, I am not sure I agree with this.

There is other information too, like the clock rate for example. But,
I think it may be a bit too much to log everything. In particular as
the information is already available via debugfs, for those that want
more information.

>
> Regards,
> Christian
>

Kind regards
Uffe

>
>
>
> From: Christian L=C3=B6hle
> Sent: Wednesday, December 8, 2021 2:02 PM
> To: linux-kernel@vger.kernel.org; linux-mmc@vger.kernel.org; Ulf Hansson;=
 Christian L=C3=B6hle
> Cc: johan@kernel.org; sudeep.holla@arm.com; linux@dominikbrodowski.net
> Subject: [PATCH] mmc: bus: Log bus width info when attaching card
>
> Add info about bus width of the attached card to the bring-up message
>
> For both MMC and SD cards the bus width that is used might
> not be obvious to a user. For MMC this might be 1, 4 or 8,
> for SD only 1 and 4. In both cases this would be a restriction
> by the host (setup). Like using an MMC in an SD slot or an
> eMMC to SD adapter.
>
> Signed-off-by: Christian Loehle <cloehle@hyperstone.com>
> ---
>  drivers/mmc/core/bus.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/mmc/core/bus.c b/drivers/mmc/core/bus.c
> index f6b7a9c5bbff..71a675dcd9b7 100644
> --- a/drivers/mmc/core/bus.c
> +++ b/drivers/mmc/core/bus.c
> @@ -358,7 +358,7 @@ int mmc_add_card(struct mmc_card *card)
>                          mmc_card_ddr52(card) ? "DDR " : "",
>                          type);
>          } else {
> -               pr_info("%s: new %s%s%s%s%s%s card at address %04x\n",
> +               pr_info("%s: new %s%s%s%s%s%s %u-bit card at address %04x=
\n",
>                          mmc_hostname(card->host),
>                          mmc_card_uhs(card) ? "ultra high speed " :
>                          (mmc_card_hs(card) ? "high speed " : ""),
> @@ -366,7 +366,8 @@ int mmc_add_card(struct mmc_card *card)
>                          (mmc_card_hs200(card) ? "HS200 " : ""),
>                          mmc_card_hs400es(card) ? "Enhanced strobe " : ""=
,
>                          mmc_card_ddr52(card) ? "DDR " : "",
> -                       uhs_bus_speed_mode, type, card->rca);
> +                       uhs_bus_speed_mode, type,
> +                       1<<card->host->ios.bus_width, card->rca);
>          }
>
>  #ifdef CONFIG_DEBUG_FS
> --
> 2.34.1
>     =3D
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