[PATCH] drm: renesas: rz-du: mipi-dsi: Drop duplicate platform_set_drvdata() call

[PATCH] drm: renesas: rz-du: mipi-dsi: Drop duplicate platform_set_drvdata() call

[Prabhakar]

From: John Madieu <john.madieu.xa@bp.renesas.com>

The platform driver data is already set earlier in
rzg2l_mipi_dsi_probe(). The subsequent platform_set_drvdata() call
uses the same arguments and is therefore redundant.

Remove the duplicate call.

Signed-off-by: John Madieu <john.madieu.xa@bp.renesas.com>
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
---
 drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c b/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c
index 5b257f5adf06..985d6e02203c 100644
--- a/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c
+++ b/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c
@@ -1576,8 +1576,6 @@ static int rzg2l_mipi_dsi_probe(struct platform_device *pdev)
 	if (!dsi->dcs_buf_virt)
 		return -ENOMEM;
 
-	platform_set_drvdata(pdev, dsi);
-
 	ret = rzg2l_mipi_dsi_pwrrdy_init(dsi);
 	if (ret)
 		return ret;
-- 
2.56.0

Re: [PATCH] drm: renesas: rz-du: mipi-dsi: Drop duplicate platform_set_drvdata() call

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found no new issues
in this patch, but noticed 1 related pre-existing issue it does not
introduce:
- [High] drm: renesas: rz-du: null pointer dereference in
  rzg2l_mipi_dsi_probe() [1]
--

commit dcaf0e503b70614276db2fd071bf963a09140504
Author: John Madieu <john.madieu.xa@bp.renesas.com>

drm: renesas: rz-du: mipi-dsi: Drop duplicate platform_set_drvdata() call

This commit removes a redundant platform_set_drvdata() call in
rzg2l_mipi_dsi_probe().

> diff --git a/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c b/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c
> index 5b257f5adf06c..985d6e02203c1 100644
> --- a/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c
> +++ b/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c
> @@ -1576,8 +1576,6 @@ static int rzg2l_mipi_dsi_probe(struct platform_device *pdev)
>  	if (!dsi->dcs_buf_virt)
>  		return -ENOMEM;
>  
> -	platform_set_drvdata(pdev, dsi);
> -
>  	ret = rzg2l_mipi_dsi_pwrrdy_init(dsi);
>  	if (ret)
>  		return ret;

[Severity: High]
This problem wasn't introduced by this patch, but can a NULL pointer
dereference occur in rzg2l_mipi_dsi_probe() [1] if the driver is
manually bound via sysfs without matching device tree data?

drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c:rzg2l_mipi_dsi_probe() {
	...
	dsi->info = of_device_get_match_data(&pdev->dev);
	...
	ret = rzg2l_mipi_dsi_pwrrdy_init(dsi);
	...
	ret = dsi->info->dphy_init(dsi, 80000000ULL * MILLI);
	...
}

of_device_get_match_data() returns NULL when no match is found, and
dsi->info is later dereferenced without a NULL check in
rzg2l_mipi_dsi_pwrrdy_init() and when calling dsi->info->dphy_init().

[1] https://sashiko.dev/#/bug/linux-14b243a7-c808-4384-b0dc-3416dc888b2a

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261110114622.229608-1-prabhakar.mahadev-lad.rj@bp.renesas.com?part=1

RE: [PATCH] drm: renesas: rz-du: mipi-dsi: Drop duplicate platform_set_drvdata() call

[Biju Das]

Hi Prabhakar,

Thanks for the patch.

> -----Original Message-----
> From: Prabhakar <prabhakar.csengg@gmail.com>
> Sent: 10 November 2026 11:46
> Subject: [PATCH] drm: renesas: rz-du: mipi-dsi: Drop duplicate platform_set_drvdata() call
> 
> From: John Madieu <john.madieu.xa@bp.renesas.com>
> 
> The platform driver data is already set earlier in rzg2l_mipi_dsi_probe(). The subsequent
> platform_set_drvdata() call uses the same arguments and is therefore redundant.
> 
> Remove the duplicate call.

Some thread related to the patch [1]. Can you please drop the first one and keep the second
one?

[1] https://lore.kernel.org/all/TY6PR01MB173770FD0BA340F5A50633E21FF322@TY6PR01MB17377.jpnprd01.prod.outlook.com/

Cheers,
Biju

> 
> Signed-off-by: John Madieu <john.madieu.xa@bp.renesas.com>
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> ---
>  drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c | 2 --
>  1 file changed, 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c b/drivers/gpu/drm/renesas/rz-
> du/rzg2l_mipi_dsi.c
> index 5b257f5adf06..985d6e02203c 100644
> --- a/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c
> +++ b/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c
> @@ -1576,8 +1576,6 @@ static int rzg2l_mipi_dsi_probe(struct platform_device *pdev)
>  	if (!dsi->dcs_buf_virt)
>  		return -ENOMEM;
> 
> -	platform_set_drvdata(pdev, dsi);
> -
>  	ret = rzg2l_mipi_dsi_pwrrdy_init(dsi);
>  	if (ret)
>  		return ret;
> --
> 2.56.0

Re: [PATCH] drm: renesas: rz-du: mipi-dsi: Drop duplicate platform_set_drvdata() call

[Lad, Prabhakar]

Hi Biju,

On Tue, Nov 10, 2026 at 11:59 AM Biju Das <biju.das.jz@bp.renesas.com> wrote:
>
> Hi Prabhakar,
>
> Thanks for the patch.
>
> > -----Original Message-----
> > From: Prabhakar <prabhakar.csengg@gmail.com>
> > Sent: 10 November 2026 11:46
> > Subject: [PATCH] drm: renesas: rz-du: mipi-dsi: Drop duplicate platform_set_drvdata() call
> >
> > From: John Madieu <john.madieu.xa@bp.renesas.com>
> >
> > The platform driver data is already set earlier in rzg2l_mipi_dsi_probe(). The subsequent
> > platform_set_drvdata() call uses the same arguments and is therefore redundant.
> >
> > Remove the duplicate call.
>
> Some thread related to the patch [1]. Can you please drop the first one and keep the second
> one?
>
Ah, I missed this thread, I will update it and send a v4.

Cheers,
Prabhakar

> [1] https://lore.kernel.org/all/TY6PR01MB173770FD0BA340F5A50633E21FF322@TY6PR01MB17377.jpnprd01.prod.outlook.com/
>

[PATCH] drm: renesas: rz-du: mipi-dsi: drop duplicate platform_set_drvdata() call

[John Madieu]

rzg2l_mipi_dsi_probe() calls platform_set_drvdata() twice with the same
arguments: once right after devm_drm_bridge_alloc() succeeds and again
after the reset controllers have been acquired. The second call is
redundant; remove it.

No functional change.

Signed-off-by: John Madieu <john.madieu.xa@bp.renesas.com>
---
 drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c b/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c
index 0b4861824319..b8527661a409 100644
--- a/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c
+++ b/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c
@@ -1441,8 +1441,6 @@ static int rzg2l_mipi_dsi_probe(struct platform_device *pdev)
 		return dev_err_probe(dsi->dev, PTR_ERR(dsi->prstc),
 				     "failed to get prst\n");
 
-	platform_set_drvdata(pdev, dsi);
-
 	pm_runtime_enable(dsi->dev);
 
 	ret = pm_runtime_resume_and_get(dsi->dev);
-- 
2.25.1

RE: [PATCH] drm: renesas: rz-du: mipi-dsi: drop duplicate platform_set_drvdata() call

[Biju Das]

Hi John,

Thanks for the patch.

> -----Original Message-----
> From: John Madieu <john.madieu.xa@bp.renesas.com>
> Sent: 25 April 2026 03:29
> Subject: [PATCH] drm: renesas: rz-du: mipi-dsi: drop duplicate platform_set_drvdata() call
> 
> rzg2l_mipi_dsi_probe() calls platform_set_drvdata() twice with the same
> arguments: once right after devm_drm_bridge_alloc() succeeds and again after the reset controllers have
> been acquired. The second call is redundant; remove it.
> 
> No functional change.
> 
> Signed-off-by: John Madieu <john.madieu.xa@bp.renesas.com>
> ---
>  drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c | 2 --
>  1 file changed, 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c b/drivers/gpu/drm/renesas/rz-
> du/rzg2l_mipi_dsi.c
> index 0b4861824319..b8527661a409 100644
> --- a/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c
> +++ b/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c
> @@ -1441,8 +1441,6 @@ static int rzg2l_mipi_dsi_probe(struct platform_device *pdev)
>  		return dev_err_probe(dsi->dev, PTR_ERR(dsi->prstc),
>  				     "failed to get prst\n");
> 
> -	platform_set_drvdata(pdev, dsi);
> -

Keep this one here and drop the earlier one as pm_runtime_resume is the first user
of drvdata.

Cheers,
Biju

>  	pm_runtime_enable(dsi->dev);
> 
>  	ret = pm_runtime_resume_and_get(dsi->dev);
> --
> 2.25.1

RE: [PATCH] drm: renesas: rz-du: mipi-dsi: drop duplicate platform_set_drvdata() call

[John Madieu]

Hi Biju,

Thank you for your review.

> -----Original Message-----
> From: Biju Das <biju.das.jz@bp.renesas.com>
> Sent: Samstag, 25. April 2026 08:40
> To: John Madieu <john.madieu.xa@bp.renesas.com>;
> maarten.lankhorst@linux.intel.com; mripard@kernel.org;
> tzimmermann@suse.de; airlied@gmail.com; simona@ffwll.ch
> Subject: RE: [PATCH] drm: renesas: rz-du: mipi-dsi: drop duplicate
> platform_set_drvdata() call
> 
> Hi John,
> 
> Thanks for the patch.
> 
> > -----Original Message-----
> > From: John Madieu <john.madieu.xa@bp.renesas.com>
> > Sent: 25 April 2026 03:29
> > Subject: [PATCH] drm: renesas: rz-du: mipi-dsi: drop duplicate
> > platform_set_drvdata() call
> >
> > rzg2l_mipi_dsi_probe() calls platform_set_drvdata() twice with the
> > same
> > arguments: once right after devm_drm_bridge_alloc() succeeds and again
> > after the reset controllers have been acquired. The second call is
> redundant; remove it.
> >
> > No functional change.
> >
> > Signed-off-by: John Madieu <john.madieu.xa@bp.renesas.com>
> > ---
> >  drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c | 2 --
> >  1 file changed, 2 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c
> > b/drivers/gpu/drm/renesas/rz- du/rzg2l_mipi_dsi.c index
> > 0b4861824319..b8527661a409 100644
> > --- a/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c
> > +++ b/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c
> > @@ -1441,8 +1441,6 @@ static int rzg2l_mipi_dsi_probe(struct
> platform_device *pdev)
> >  		return dev_err_probe(dsi->dev, PTR_ERR(dsi->prstc),
> >  				     "failed to get prst\n");
> >
> > -	platform_set_drvdata(pdev, dsi);
> > -
> 
> Keep this one here and drop the earlier one as pm_runtime_resume is the
> first user of drvdata.
> 

Got it. I'll post a v2 with the appropriate change.

Regards,
John