2023-08-03 14:14:10

by Eugen Hristev

[permalink] [raw]
Subject: Re: [PATCH v8 3/8] drm/mediatek: Fix using wrong drm private data to bind mediatek-drm

On 8/2/23 17:47, Jason-JH.Lin wrote:
> In mtk_drm_kms_init(), each element in all_drm_priv should has one
> display path private data only, such as:
> all_drm_priv[CRTC_MAIN] should has main_path data only
> all_drm_priv[CRTC_EXT] should has ext_path data only
> all_drm_priv[CRTC_THIRD] should has third_path data only

s/should has/should have/ ?

>
> So we need to add the length checking for each display path before
> assigning their drm private data into all_drm_priv array.
>
> Fixes: 1ef7ed48356c ("drm/mediatek: Modify mediatek-drm for mt8195 multi mmsys support")
> Signed-off-by: Jason-JH.Lin <[email protected]>
> Reviewed-by: AngeloGioacchino Del Regno <[email protected]>
> Reviewed-by: CK Hu <[email protected]>
> ---
> drivers/gpu/drm/mediatek/mtk_drm_drv.c | 16 +++++++++++++---
> 1 file changed, 13 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
> index 89a38561ba27..c12886f31e54 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
> @@ -351,6 +351,7 @@ static bool mtk_drm_get_all_drm_priv(struct device *dev)
> {
> struct mtk_drm_private *drm_priv = dev_get_drvdata(dev);
> struct mtk_drm_private *all_drm_priv[MAX_CRTC];
> + struct mtk_drm_private *temp_drm_priv;
> struct device_node *phandle = dev->parent->of_node;
> const struct of_device_id *of_id;
> struct device_node *node;
> @@ -373,9 +374,18 @@ static bool mtk_drm_get_all_drm_priv(struct device *dev)
> if (!drm_dev || !dev_get_drvdata(drm_dev))
> continue;
>
> - all_drm_priv[cnt] = dev_get_drvdata(drm_dev);
> - if (all_drm_priv[cnt] && all_drm_priv[cnt]->mtk_drm_bound)
> - cnt++;
> + temp_drm_priv = dev_get_drvdata(drm_dev);
> + if (temp_drm_priv) {

This is inside a 'for' loop right ?
Why don't you just 'continue' if temp_drm_priv is null ?


> + if (temp_drm_priv->mtk_drm_bound)
> + cnt++;
> +
> + if (temp_drm_priv->data->main_len)
> + all_drm_priv[CRTC_MAIN] = temp_drm_priv;
> + else if (temp_drm_priv->data->ext_len)
> + all_drm_priv[CRTC_EXT] = temp_drm_priv;
> + else if (temp_drm_priv->data->third_len)
> + all_drm_priv[CRTC_THIRD] = temp_drm_priv;
> + }
> }
>
> if (drm_priv->data->mmsys_dev_num == cnt) {



2023-08-05 08:40:42

by Jason-JH.Lin

[permalink] [raw]
Subject: Re: [PATCH v8 3/8] drm/mediatek: Fix using wrong drm private data to bind mediatek-drm

Hi Eugen,

Thanks for the reviews.

On Thu, 2023-08-03 at 16:22 +0300, Eugen Hristev wrote:
> On 8/2/23 17:47, Jason-JH.Lin wrote:
> > In mtk_drm_kms_init(), each element in all_drm_priv should has one
> > display path private data only, such as:
> > all_drm_priv[CRTC_MAIN] should has main_path data only
> > all_drm_priv[CRTC_EXT] should has ext_path data only
> > all_drm_priv[CRTC_THIRD] should has third_path data only
>
> s/should has/should have/ ?
>

Although each element is singular, `should have` is correct.

`should` is an auxiliary verb, so we can only use infinitive verbs
after that.

So this part of comment should be like this:
In mtk_drm_kms_init(), each element in all_drm_priv should have one
display path private data, such as:
all_drm_priv[CRTC_MAIN] should only have main_path data
all_drm_priv[CRTC_EXT] should only have ext_path data
all_drm_priv[CRTC_THIRD] should only have third_path data

Right?

> >
> > So we need to add the length checking for each display path before
> > assigning their drm private data into all_drm_priv array.
> >
> > Fixes: 1ef7ed48356c ("drm/mediatek: Modify mediatek-drm for mt8195
> > multi mmsys support")
> > Signed-off-by: Jason-JH.Lin <[email protected]>
> > Reviewed-by: AngeloGioacchino Del Regno <
> > [email protected]>
> > Reviewed-by: CK Hu <[email protected]>
> > ---
> > drivers/gpu/drm/mediatek/mtk_drm_drv.c | 16 +++++++++++++---
> > 1 file changed, 13 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c
> > b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
> > index 89a38561ba27..c12886f31e54 100644
> > --- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c
> > +++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
> > @@ -351,6 +351,7 @@ static bool mtk_drm_get_all_drm_priv(struct
> > device *dev)
> > {
> > struct mtk_drm_private *drm_priv = dev_get_drvdata(dev);
> > struct mtk_drm_private *all_drm_priv[MAX_CRTC];
> > + struct mtk_drm_private *temp_drm_priv;
> > struct device_node *phandle = dev->parent->of_node;
> > const struct of_device_id *of_id;
> > struct device_node *node;
> > @@ -373,9 +374,18 @@ static bool mtk_drm_get_all_drm_priv(struct
> > device *dev)
> > if (!drm_dev || !dev_get_drvdata(drm_dev))
> > continue;
> >
> > - all_drm_priv[cnt] = dev_get_drvdata(drm_dev);
> > - if (all_drm_priv[cnt] && all_drm_priv[cnt]-
> > >mtk_drm_bound)
> > - cnt++;
> > + temp_drm_priv = dev_get_drvdata(drm_dev);
> > + if (temp_drm_priv) {
>
> This is inside a 'for' loop right ?
> Why don't you just 'continue' if temp_drm_priv is null ?
>

Yes, you are right.
I'll use `if (!temp_drm_priv) continue;` to make this statement
simpler. Thanks.

Regards,
Jason-JH.Lin.

>
> > + if (temp_drm_priv->mtk_drm_bound)
> > + cnt++;
> > +
> > + if (temp_drm_priv->data->main_len)
> > + all_drm_priv[CRTC_MAIN] =
> > temp_drm_priv;
> > + else if (temp_drm_priv->data->ext_len)
> > + all_drm_priv[CRTC_EXT] = temp_drm_priv;
> > + else if (temp_drm_priv->data->third_len)
> > + all_drm_priv[CRTC_THIRD] =
> > temp_drm_priv;
> > + }
> > }
> >
> > if (drm_priv->data->mmsys_dev_num == cnt) {
>
>