Hi,
On 7/27/23 19:41, Jason-JH.Lin wrote:
> Add checking the length of each data path before assigning 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]>
> ---
> 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 249c9fd6347e..d2fb1fb4e682 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) {
> + if (temp_drm_priv->mtk_drm_bound)
> + cnt++;
> +
> + if (temp_drm_priv->data->main_len)
> + all_drm_priv[0] = temp_drm_priv;
> + else if (temp_drm_priv->data->ext_len)
> + all_drm_priv[1] = temp_drm_priv;
> + else if (temp_drm_priv->data->third_len)
> + all_drm_priv[2] = temp_drm_priv;
> + }
Previously the code was assigning stuff into all_drm_priv[cnt] and
incrementing it.
With your change, it assigns to all_drm_priv[0], [1], [2]. Is this what
you intended ?
If this loop has second run, you will reassign to all_drm_priv again ?
I would expect you to take `cnt` into account.
Also, is it expected that all_drm_priv has holes in the array ?
Eugen
> }
>
> if (drm_priv->data->mmsys_dev_num == cnt) {
Hi Eugen,
Thanks for the reviews.
On Fri, 2023-07-28 at 11:47 +0300, Eugen Hristev wrote:
> Hi,
>
> On 7/27/23 19:41, Jason-JH.Lin wrote:
> > Add checking the length of each data path before assigning 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]>
> > ---
> > 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 249c9fd6347e..d2fb1fb4e682 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) {
> > + if (temp_drm_priv->mtk_drm_bound)
> > + cnt++;
> > +
> > + if (temp_drm_priv->data->main_len)
> > + all_drm_priv[0] = temp_drm_priv;
> > + else if (temp_drm_priv->data->ext_len)
> > + all_drm_priv[1] = temp_drm_priv;
> > + else if (temp_drm_priv->data->third_len)
> > + all_drm_priv[2] = temp_drm_priv;
> > + }
>
> Previously the code was assigning stuff into all_drm_priv[cnt] and
> incrementing it.
> With your change, it assigns to all_drm_priv[0], [1], [2]. Is this
> what
> you intended ?
Because dev_get_drvdata(drm_dev) will get the driver data by drm_dev.
Each drm_dev represents a display path.
e,g.
drm_dev of "mediatek,mt8195-vdosys0" represents main path.
drm_dev of "mediatek,mt8195-vdosys1" represents ext path.
So we want to make sure all_drm_priv[] store the private data in
the order of display path, such as:
all_drm_priv[0] = the private data of main display
all_drm_priv[1] = the private data of ext display
all_drm_priv[2] = the private data of third display
> If this loop has second run, you will reassign to all_drm_priv again
> ?
Because the previous code will store all_drm_priv[] in the order of
mtk_drm_bind() was called.
If drm_dev of ext path bound earlier than drm_dev of main path,
all_drm_priv[] in mtk_drm_get_all_drm_priv() may be re-assigned like
this:
all_drm_priv[0]->all_drm_priv[0] = private data of ext path
all_drm_priv[1]->all_drm_priv[0] = private data of ext path
all_drm_priv[0]->all_drm_priv[1] = private data of main path
all_drm_priv[1]->all_drm_priv[1] = private data of main path
But we expect all_drm_priv[] be re-assigned like this:
all_drm_priv[0]->all_drm_priv[0] = private data of main path
all_drm_priv[1]->all_drm_priv[0] = private data of main path
all_drm_priv[0]->all_drm_priv[1] = private data of ext path
all_drm_priv[1]->all_drm_priv[1] = private data of ext path
> I would expect you to take `cnt` into account.
> Also, is it expected that all_drm_priv has holes in the array ?
Each drm_dev will only called mtk_drm_bind() once, so all holes
will be filled after all drm_dev has called mtk_drm_bind().
Do you agree with this statement? :)
Regards,
Jason-JH.Lin
>
> Eugen
>
>
>
> > }
> >
> > if (drm_priv->data->mmsys_dev_num == cnt) {
>
>