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References: <20230404104800.301150-1-angelogioacchino.delregno@collabora.com> <20230404104800.301150-6-angelogioacchino.delregno@collabora.com>
In-Reply-To: <20230404104800.301150-6-angelogioacchino.delregno@collabora.com>
From:   Chen-Yu Tsai <wenst@chromium.org>
Date:   Thu, 6 Apr 2023 14:20:41 +0800
Message-ID: <CAGXv+5HTPd_2r0Bb2nY94gUwWzpn_wvU_ZMYu6u9hWBeaVzrwA@mail.gmail.com>
Subject: Re: [PATCH v3 5/9] drm/mediatek: dp: Change logging to dev for mtk_dp_aux_transfer()
To:     AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@collabora.com>
Cc:     chunkuang.hu@kernel.org, p.zabel@pengutronix.de, airlied@gmail.com,
        daniel@ffwll.ch, matthias.bgg@gmail.com,
        dri-devel@lists.freedesktop.org,
        linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, kernel@collabora.com
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On Tue, Apr 4, 2023 at 6:48=E2=80=AFPM AngeloGioacchino Del Regno
<angelogioacchino.delregno@collabora.com> wrote:
>
> Change logging from drm_{err,info}() to dev_{err,info}() in functions
> mtk_dp_aux_transfer() and mtk_dp_aux_do_transfer(): this will be
> essential to avoid getting NULL pointer kernel panics if any kind
> of error happens during AUX transfers happening before the bridge
> is attached.
>
> This may potentially start happening in a later commit implementing
> aux-bus support, as AUX transfers will be triggered from the panel
> driver (for EDID) before the mtk-dp bridge gets attached, and it's
> done in preparation for the same.
>
> Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@coll=
abora.com>
> ---
>  drivers/gpu/drm/mediatek/mtk_dp.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_dp.c b/drivers/gpu/drm/mediatek=
/mtk_dp.c
> index ac21eca0e20e..19b145cf2e05 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dp.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dp.c
> @@ -849,7 +849,7 @@ static int mtk_dp_aux_do_transfer(struct mtk_dp *mtk_=
dp, bool is_read, u8 cmd,
>                 u32 phy_status =3D mtk_dp_read(mtk_dp, MTK_DP_AUX_P0_3628=
) &
>                                  AUX_RX_PHY_STATE_AUX_TX_P0_MASK;
>                 if (phy_status !=3D AUX_RX_PHY_STATE_AUX_TX_P0_RX_IDLE) {
> -                       drm_err(mtk_dp->drm_dev,
> +                       dev_err(mtk_dp->dev,
>                                 "AUX Rx Aux hang, need SW reset\n");
>                         return -EIO;
>                 }
> @@ -2061,7 +2061,7 @@ static ssize_t mtk_dp_aux_transfer(struct drm_dp_au=
x *mtk_aux,
>                 is_read =3D true;
>                 break;
>         default:
> -               drm_err(mtk_aux->drm_dev, "invalid aux cmd =3D %d\n",
> +               dev_err(mtk_dp->dev, "invalid aux cmd =3D %d\n",
>                         msg->request);
>                 ret =3D -EINVAL;
>                 goto err;
> @@ -2077,7 +2077,7 @@ static ssize_t mtk_dp_aux_transfer(struct drm_dp_au=
x *mtk_aux,
>                                              to_access);
>
>                 if (ret) {
> -                       drm_info(mtk_dp->drm_dev,
> +                       dev_info(mtk_dp->dev,
>                                  "Failed to do AUX transfer: %d\n", ret);

This part no longer applies cleanly due to

    drm/mediatek: dp: Change the aux retries times when receiving AUX_DEFER

Also I think all these calls could be collapsed into one line?

ChenYu

>                         goto err;
>                 }
> --
> 2.40.0
>