Re: [PATCH v4 2/2] drm/mediatek: dpi/dsi: fix possible_crtcs calculation
From: Chun-Kuang Hu
Date: Thu Nov 23 2023 - 10:33:35 EST
Hi, Michael:
Michael Walle <mwalle@xxxxxxxxxx> 於 2023年11月21日 週二 下午10:44寫道：
>
> Hi,
>
> > mtk_drm_find_possible_crtc_by_comp() assumed that the main path will
> > always have the CRTC with id 0, the ext id 1 and the third id 2. This
> > is only true if the paths are all available. But paths are optional
> > (see
> > also comment in mtk_drm_kms_init()), e.g. the main path might not be
> > enabled or available at all. Then the CRTC IDs will shift one up, e.g.
> > ext will be 0 and the third path will be 1.
> >
> > To fix that, dynamically calculate the IDs by the presence of the
> > paths.
> >
> > While at it, make the return code a signed one and return -ENOENT if no
> > path is found and handle the error in the callers.
> >
> > Fixes: 5aa8e7647676 ("drm/mediatek: dpi/dsi: Change the getting
> > possible_crtc way")
> > Suggested-by: Nícolas F. R. A. Prado <nfraprado@xxxxxxxxxxxxx>
> > Signed-off-by: Michael Walle <mwalle@xxxxxxxxxx>
> > Reviewed-by: Nícolas F. R. A. Prado <nfraprado@xxxxxxxxxxxxx>
> > Tested-by: Nícolas F. R. A. Prado <nfraprado@xxxxxxxxxxxxx>
>
> Is there anything wrong with these two patches? They are now lingering
> around for more than two months.
>
> Unfortunately, patch 2/2 won't apply anymore because of commit
> 01389b324c97 ("drm/mediatek: Add connector dynamic selection
> capability). And I'm a bit puzzled for what the crtc_id is used
> there because I guess it will have the same problem this patch
> fixes.
Please base on the latest kernel version to fix.
Regards,
Chun-Kuang.
>
> -michael
>
> > ---
> > v4:
> > - return -ENOENT if mtk_drm_find_possible_crtc_by_comp() doesn't find
> > any path
> > v3:
> > - use data instead of priv_n->data
> > - fixed typos
> > - collected Rb and Tb tags
> > v2:
> > - iterate over all_drm_private[] to get any vdosys
> > - new check if a path is available
> > ---
> > drivers/gpu/drm/mediatek/mtk_dpi.c | 5 +-
> > drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c | 75 ++++++++++++++++-----
> > drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h | 3 +-
> > drivers/gpu/drm/mediatek/mtk_dsi.c | 5 +-
> > 4 files changed, 68 insertions(+), 20 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c
> > b/drivers/gpu/drm/mediatek/mtk_dpi.c
> > index 2f931e4e2b60..f9250f7ee706 100644
> > --- a/drivers/gpu/drm/mediatek/mtk_dpi.c
> > +++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
> > @@ -796,7 +796,10 @@ static int mtk_dpi_bind(struct device *dev, struct
> > device *master, void *data)
> > return ret;
> > }
> >
> > - dpi->encoder.possible_crtcs =
> > mtk_drm_find_possible_crtc_by_comp(drm_dev, dpi->dev);
> > + ret = mtk_drm_find_possible_crtc_by_comp(drm_dev, dpi->dev);
> > + if (ret < 0)
> > + goto err_cleanup;
> > + dpi->encoder.possible_crtcs = ret;
> >
> > ret = drm_bridge_attach(&dpi->encoder, &dpi->bridge, NULL,
> > DRM_BRIDGE_ATTACH_NO_CONNECTOR);
> > diff --git a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
> > b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
> > index 771f4e173353..83ae75ecd858 100644
> > --- a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
> > +++ b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
> > @@ -507,6 +507,27 @@ static bool mtk_drm_find_comp_in_ddp(struct device
> > *dev,
> > return false;
> > }
> >
> > +static bool mtk_ddp_path_available(const unsigned int *path,
> > + unsigned int path_len,
> > + struct device_node **comp_node)
> > +{
> > + unsigned int i;
> > +
> > + if (!path)
> > + return false;
> > +
> > + for (i = 0U; i < path_len; i++) {
> > + /* OVL_ADAPTOR doesn't have a device node */
> > + if (path[i] == DDP_COMPONENT_DRM_OVL_ADAPTOR)
> > + continue;
> > +
> > + if (!comp_node[path[i]])
> > + return false;
> > + }
> > +
> > + return true;
> > +}
> > +
> > int mtk_ddp_comp_get_id(struct device_node *node,
> > enum mtk_ddp_comp_type comp_type)
> > {
> > @@ -522,25 +543,47 @@ int mtk_ddp_comp_get_id(struct device_node *node,
> > return -EINVAL;
> > }
> >
> > -unsigned int mtk_drm_find_possible_crtc_by_comp(struct drm_device
> > *drm,
> > - struct device *dev)
> > +int mtk_drm_find_possible_crtc_by_comp(struct drm_device *drm, struct
> > device *dev)
> > {
> > struct mtk_drm_private *private = drm->dev_private;
> > - unsigned int ret = 0;
> > -
> > - if (mtk_drm_find_comp_in_ddp(dev, private->data->main_path,
> > private->data->main_len,
> > - private->ddp_comp))
> > - ret = BIT(0);
> > - else if (mtk_drm_find_comp_in_ddp(dev, private->data->ext_path,
> > - private->data->ext_len, private->ddp_comp))
> > - ret = BIT(1);
> > - else if (mtk_drm_find_comp_in_ddp(dev, private->data->third_path,
> > - private->data->third_len, private->ddp_comp))
> > - ret = BIT(2);
> > - else
> > - DRM_INFO("Failed to find comp in ddp table\n");
> > + const struct mtk_mmsys_driver_data *data;
> > + struct mtk_drm_private *priv_n;
> > + int i = 0, j;
> > +
> > + for (j = 0; j < private->data->mmsys_dev_num; j++) {
> > + priv_n = private->all_drm_private[j];
> > + data = priv_n->data;
> > +
> > + if (mtk_ddp_path_available(data->main_path, data->main_len,
> > + priv_n->comp_node)) {
> > + if (mtk_drm_find_comp_in_ddp(dev, data->main_path,
> > + data->main_len,
> > + priv_n->ddp_comp))
> > + return BIT(i);
> > + i++;
> > + }
> > +
> > + if (mtk_ddp_path_available(data->ext_path, data->ext_len,
> > + priv_n->comp_node)) {
> > + if (mtk_drm_find_comp_in_ddp(dev, data->ext_path,
> > + data->ext_len,
> > + priv_n->ddp_comp))
> > + return BIT(i);
> > + i++;
> > + }
> > +
> > + if (mtk_ddp_path_available(data->third_path, data->third_len,
> > + priv_n->comp_node)) {
> > + if (mtk_drm_find_comp_in_ddp(dev, data->third_path,
> > + data->third_len,
> > + priv_n->ddp_comp))
> > + return BIT(i);
> > + i++;
> > + }
> > + }
> >
> > - return ret;
> > + DRM_INFO("Failed to find comp in ddp table\n");
> > + return -ENOENT;
> > }
> >
> > int mtk_ddp_comp_init(struct device_node *node, struct mtk_ddp_comp
> > *comp,
> > diff --git a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h
> > b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h
> > index febcaeef16a1..6a95df72de0a 100644
> > --- a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h
> > +++ b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h
> > @@ -277,8 +277,7 @@ static inline bool mtk_ddp_comp_disconnect(struct
> > mtk_ddp_comp *comp, struct dev
> >
> > int mtk_ddp_comp_get_id(struct device_node *node,
> > enum mtk_ddp_comp_type comp_type);
> > -unsigned int mtk_drm_find_possible_crtc_by_comp(struct drm_device
> > *drm,
> > - struct device *dev);
> > +int mtk_drm_find_possible_crtc_by_comp(struct drm_device *drm, struct
> > device *dev);
> > int mtk_ddp_comp_init(struct device_node *comp_node, struct
> > mtk_ddp_comp *comp,
> > unsigned int comp_id);
> > enum mtk_ddp_comp_type mtk_ddp_comp_get_type(unsigned int comp_id);
> > diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c
> > b/drivers/gpu/drm/mediatek/mtk_dsi.c
> > index d8bfc2cce54d..d67e5c61a9b9 100644
> > --- a/drivers/gpu/drm/mediatek/mtk_dsi.c
> > +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
> > @@ -843,7 +843,10 @@ static int mtk_dsi_encoder_init(struct drm_device
> > *drm, struct mtk_dsi *dsi)
> > return ret;
> > }
> >
> > - dsi->encoder.possible_crtcs = mtk_drm_find_possible_crtc_by_comp(drm,
> > dsi->host.dev);
> > + ret = mtk_drm_find_possible_crtc_by_comp(drm, dsi->host.dev);
> > + if (ret < 0)
> > + goto err_cleanup_encoder;
> > + dsi->encoder.possible_crtcs = ret;
> >
> > ret = drm_bridge_attach(&dsi->encoder, &dsi->bridge, NULL,
> > DRM_BRIDGE_ATTACH_NO_CONNECTOR);