Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
MIME-Version: 1.0
References: <0d0ef6651ed44fc780e95c8797294708@hyperstone.com>
In-Reply-To: <0d0ef6651ed44fc780e95c8797294708@hyperstone.com>
From:   Ulf Hansson <ulf.hansson@linaro.org>
Date:   Mon, 10 Oct 2022 16:17:30 +0200
Message-ID: <CAPDyKFrxDBnOZXD_e086ODRFthKVrsTTU9jgsWayXXkHby2RLQ@mail.gmail.com>
Subject: Re: [PATCHv3 1/2] mmc: block: Remove error check of hw_reset on reset
To:     =?UTF-8?Q?Christian_L=C3=B6hle?= <CLoehle@hyperstone.com>
Cc:     Adrian Hunter <adrian.hunter@intel.com>,
        Linux MMC List <linux-mmc@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

On Mon, 10 Oct 2022 at 16:03, Christian L=C3=B6hle <CLoehle@hyperstone.com>=
 wrote:
>
> Before switching back to the right partition in mmc_blk_reset
> there used to be a check if hw_reset was even supported.
> This return value was removed, so there is no reason to check.
> Furthermore ensure part_curr is not falsely set to a valid value
> on reset or partition switch error.
>
> Fixes: fefdd3c91e0a ("mmc: core: Drop superfluous validations in mmc_hw|s=
w_reset()")
> Cc: stable@vger.kernel.org
>
> Signed-off-by: Christian Loehle <cloehle@hyperstone.com>

This looks good to me, however I am awaiting and ack from Adrian
before applying, to make sure we are all aligned with the approach.

Kind regards
Uffe

> ---
> -v3: Ensure invalid part_curr on error
> -v2: Do not attempt to switch partitions if reset failed
>
>  drivers/mmc/core/block.c | 29 ++++++++++++++---------------
>  1 file changed, 14 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
> index ce89611a136e..45a44edcc31a 100644
> --- a/drivers/mmc/core/block.c
> +++ b/drivers/mmc/core/block.c
> @@ -134,6 +134,7 @@ struct mmc_blk_data {
>          * track of the current selected device partition.
>          */
>         unsigned int    part_curr;
> +#define MMC_BLK_PART_INVALID   UINT_MAX        /* Unknown partition acti=
ve */
>         int     area_type;
>
>         /* debugfs files (only in main mmc_blk_data) */
> @@ -991,29 +992,27 @@ static int mmc_blk_reset(struct mmc_blk_data *md, s=
truct mmc_host *host,
>                          int type)
>  {
>         int err;
> +       struct mmc_blk_data *main_md =3D dev_get_drvdata(&host->card->dev=
);
> +       int part_err;
>
>         if (md->reset_done & type)
>                 return -EEXIST;
>
>         md->reset_done |=3D type;
> +       main_md->part_curr =3D MMC_BLK_PART_INVALID;
>         err =3D mmc_hw_reset(host->card);
> +       if (err)
> +               return err;
>         /* Ensure we switch back to the correct partition */
> -       if (err) {
> -               struct mmc_blk_data *main_md =3D
> -                       dev_get_drvdata(&host->card->dev);
> -               int part_err;
> -
> -               main_md->part_curr =3D main_md->part_type;
> -               part_err =3D mmc_blk_part_switch(host->card, md->part_typ=
e);
> -               if (part_err) {
> -                       /*
> -                        * We have failed to get back into the correct
> -                        * partition, so we need to abort the whole reque=
st.
> -                        */
> -                       return -ENODEV;
> -               }
> +       part_err =3D mmc_blk_part_switch(host->card, md->part_type);
> +       if (part_err) {
> +               /*
> +                * We have failed to get back into the correct
> +                * partition, so we need to abort the whole request.
> +                */
> +               return -ENODEV;
>         }
> -       return err;
> +       return 0;
>  }
>
>  static inline void mmc_blk_reset_success(struct mmc_blk_data *md, int ty=
pe)
> --
> 2.37.3
> Hyperstone GmbH | Reichenaustr. 39a  | 78467 Konstanz
> Managing Director: Dr. Jan Peter Berns.
> Commercial register of local courts: Freiburg HRB381782
>