[PATCH] drm/mediatek: dp: Add phy_mtk_dp module as pre-dependency

[PATCH] drm/mediatek: dp: Add phy_mtk_dp module as pre-dependency

[Nícolas F. R. A. Prado]

The mtk_dp driver registers a phy device which is handled by the
phy_mtk_dp driver and assumes that the phy probe will complete
synchronously, proceeding to make use of functionality exposed by that
driver right away. This assumption however is false when the phy driver
is built as a module, causing the mtk_dp driver to fail probe in this
case.

Add the phy_mtk_dp module as a pre-dependency to the mtk_dp module to
ensure the phy module has been loaded before the dp, so that the phy
probe happens synchrounously and the mtk_dp driver can probe
successfully even with the phy driver built as a module.

Fixes: f70ac097a2cf ("drm/mediatek: Add MT8195 Embedded DisplayPort driver")
Signed-off-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>

---

 drivers/gpu/drm/mediatek/mtk_dp.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/mediatek/mtk_dp.c b/drivers/gpu/drm/mediatek/mtk_dp.c
index e4c16ba9902d..2136a596efa1 100644
--- a/drivers/gpu/drm/mediatek/mtk_dp.c
+++ b/drivers/gpu/drm/mediatek/mtk_dp.c
@@ -2818,3 +2818,4 @@ MODULE_AUTHOR("Markus Schneider-Pargmann <msp@baylibre.com>");
 MODULE_AUTHOR("Bo-Chen Chen <rex-bc.chen@mediatek.com>");
 MODULE_DESCRIPTION("MediaTek DisplayPort Driver");
 MODULE_LICENSE("GPL");
+MODULE_SOFTDEP("pre: phy_mtk_dp");
-- 
2.42.1

Re: [PATCH] drm/mediatek: dp: Add phy_mtk_dp module as pre-dependency

[AngeloGioacchino Del Regno]

Il 20/11/23 21:28, Nícolas F. R. A. Prado ha scritto:
> The mtk_dp driver registers a phy device which is handled by the
> phy_mtk_dp driver and assumes that the phy probe will complete
> synchronously, proceeding to make use of functionality exposed by that
> driver right away. This assumption however is false when the phy driver
> is built as a module, causing the mtk_dp driver to fail probe in this
> case.
> 
> Add the phy_mtk_dp module as a pre-dependency to the mtk_dp module to
> ensure the phy module has been loaded before the dp, so that the phy
> probe happens synchrounously and the mtk_dp driver can probe
> successfully even with the phy driver built as a module.
> 

You forgot a Suggested-by here :-P

> Fixes: f70ac097a2cf ("drm/mediatek: Add MT8195 Embedded DisplayPort driver")
> Signed-off-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>

It's fine anyway; being the best solution that we can use:

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>

> 
> ---
> 
>   drivers/gpu/drm/mediatek/mtk_dp.c | 1 +
>   1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_dp.c b/drivers/gpu/drm/mediatek/mtk_dp.c
> index e4c16ba9902d..2136a596efa1 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dp.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dp.c
> @@ -2818,3 +2818,4 @@ MODULE_AUTHOR("Markus Schneider-Pargmann <msp@baylibre.com>");
>   MODULE_AUTHOR("Bo-Chen Chen <rex-bc.chen@mediatek.com>");
>   MODULE_DESCRIPTION("MediaTek DisplayPort Driver");
>   MODULE_LICENSE("GPL");
> +MODULE_SOFTDEP("pre: phy_mtk_dp");

Re: [PATCH] drm/mediatek: dp: Add phy_mtk_dp module as pre-dependency

[Nícolas F. R. A. Prado]

On Tue, Nov 21, 2023 at 11:59:14AM +0100, AngeloGioacchino Del Regno wrote:
> Il 20/11/23 21:28, Nícolas F. R. A. Prado ha scritto:
> > The mtk_dp driver registers a phy device which is handled by the
> > phy_mtk_dp driver and assumes that the phy probe will complete
> > synchronously, proceeding to make use of functionality exposed by that
> > driver right away. This assumption however is false when the phy driver
> > is built as a module, causing the mtk_dp driver to fail probe in this
> > case.
> > 
> > Add the phy_mtk_dp module as a pre-dependency to the mtk_dp module to
> > ensure the phy module has been loaded before the dp, so that the phy
> > probe happens synchrounously and the mtk_dp driver can probe
> > successfully even with the phy driver built as a module.
> > 
> 
> You forgot a Suggested-by here :-P

Oops, sorry, I forgot that tag existed. Will send a v2 with it added :).

> 
> > Fixes: f70ac097a2cf ("drm/mediatek: Add MT8195 Embedded DisplayPort driver")
> > Signed-off-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
> 
> It's fine anyway; being the best solution that we can use:
> 
> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
> 
> > 
> > ---
> > 
> >   drivers/gpu/drm/mediatek/mtk_dp.c | 1 +
> >   1 file changed, 1 insertion(+)
> > 
> > diff --git a/drivers/gpu/drm/mediatek/mtk_dp.c b/drivers/gpu/drm/mediatek/mtk_dp.c
> > index e4c16ba9902d..2136a596efa1 100644
> > --- a/drivers/gpu/drm/mediatek/mtk_dp.c
> > +++ b/drivers/gpu/drm/mediatek/mtk_dp.c
> > @@ -2818,3 +2818,4 @@ MODULE_AUTHOR("Markus Schneider-Pargmann <msp@baylibre.com>");
> >   MODULE_AUTHOR("Bo-Chen Chen <rex-bc.chen@mediatek.com>");
> >   MODULE_DESCRIPTION("MediaTek DisplayPort Driver");
> >   MODULE_LICENSE("GPL");
> > +MODULE_SOFTDEP("pre: phy_mtk_dp");
>