[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <6c07d1bc12c9226bf623da0a46ffaadb151c2175.camel@mediatek.com>
Date: Mon, 31 Jul 2023 08:21:28 +0000
From: Jason-JH Lin (林睿祥)
<Jason-JH.Lin@...iatek.com>
To: "chunkuang.hu@...nel.org" <chunkuang.hu@...nel.org>,
"angelogioacchino.delregno@...labora.com"
<angelogioacchino.delregno@...labora.com>,
"eugen.hristev@...labora.com" <eugen.hristev@...labora.com>
CC: "linux-mediatek@...ts.infradead.org"
<linux-mediatek@...ts.infradead.org>,
Singo Chang (張興國)
<Singo.Chang@...iatek.com>,
Johnson Wang (王聖鑫)
<Johnson.Wang@...iatek.com>,
Jason-ch Chen (陳建豪)
<Jason-ch.Chen@...iatek.com>,
Shawn Sung (宋孝謙)
<Shawn.Sung@...iatek.com>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
Nancy Lin (林欣螢) <Nancy.Lin@...iatek.com>,
"dri-devel@...ts.freedesktop.org" <dri-devel@...ts.freedesktop.org>,
Project_Global_Chrome_Upstream_Group
<Project_Global_Chrome_Upstream_Group@...iatek.com>,
"linux-arm-kernel@...ts.infradead.org"
<linux-arm-kernel@...ts.infradead.org>,
"matthias.bgg@...il.com" <matthias.bgg@...il.com>
Subject: Re: [PATCH v7 2/4] drm/mediatek: Fix using wrong drm private data to
bind mediatek-drm
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 <jason-jh.lin@...iatek.com>
> > ---
> > 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) {
>
>
Powered by blists - more mailing lists