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Date:   Sun, 24 Jan 2021 09:43:07 +0000
From:   Paul Cercueil <paul@crapouillou.net>
Subject: Re: [PATCH v3 4/4] drm/ingenic: Fix non-OSD mode
To:     "H. Nikolaus Schaller" <hns@goldelico.com>
Cc:     David Airlie <airlied@linux.ie>, Daniel Vetter <daniel@ffwll.ch>,
        Sam Ravnborg <sam@ravnborg.org>,
        Laurent Pinchart <Laurent.pinchart@ideasonboard.com>,
        od@zcrc.me, dri-devel@lists.freedesktop.org,
        linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org,
        stable@vger.kernel.org, Daniel Vetter <daniel.vetter@ffwll.ch>
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In-Reply-To: <30F302B6-04A1-472B-B026-009F7665E39C@goldelico.com>
References: <20210124085552.29146-1-paul@crapouillou.net>
        <20210124085552.29146-5-paul@crapouillou.net>
        <30F302B6-04A1-472B-B026-009F7665E39C@goldelico.com>
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Hi Nikolaus,

Le dim. 24 janv. 2021 ? 10:30, H. Nikolaus Schaller 
<hns@goldelico.com> a ?crit :
> Hi Paul,
> we observed the same issue on the jz4730 (which is almost identical
> to the jz4740 wrt. LCDC) and our solution [1] was simpler.
> 
> It leaves the hwdesc f0 and f1 as they are and just takes f1 for 
> really
> programming the first DMA descriptor if there is no OSD.

Disagreed. With your solution, it ends up using priv->f1 plane with 
hwdesc_f0. That's very confusing.

> We have tested on jz4730 and jz4780.

Could I get a tested-by then? :)

Cheers,
-Paul

> Maybe you want to consider that. Then I can officially post it.
> 
> [1] 
> https://github.com/goldelico/letux-kernel/commit/3be1de5fdabf2cc1c17f198ded3328cc6e4b9844
> 
>>  Am 24.01.2021 um 09:55 schrieb Paul Cercueil <paul@crapouillou.net>:
>> 
>>  Even though the JZ4740 did not have the OSD mode, it had (according 
>> to
>>  the documentation) two DMA channels, but there is absolutely no
>>  information about how to select the second DMA channel.
>> 
>>  Make the ingenic-drm driver work in non-OSD mode by using the
>>  foreground0 plane (which is bound to the DMA0 channel) as the 
>> primary
>>  plane, instead of the foreground1 plane, which is the primary plane
>>  when in OSD mode.
>> 
>>  Fixes: 3c9bea4ef32b ("drm/ingenic: Add support for OSD mode")
>>  Cc: <stable@vger.kernel.org> # v5.8+
>>  Signed-off-by: Paul Cercueil <paul@crapouillou.net>
>>  Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
>>  ---
>>  drivers/gpu/drm/ingenic/ingenic-drm-drv.c | 11 +++++++----
>>  1 file changed, 7 insertions(+), 4 deletions(-)
>> 
>>  diff --git a/drivers/gpu/drm/ingenic/ingenic-drm-drv.c 
>> b/drivers/gpu/drm/ingenic/ingenic-drm-drv.c
>>  index b23011c1c5d9..59ce43862e16 100644
>>  --- a/drivers/gpu/drm/ingenic/ingenic-drm-drv.c
>>  +++ b/drivers/gpu/drm/ingenic/ingenic-drm-drv.c
>>  @@ -554,7 +554,7 @@ static void 
>> ingenic_drm_plane_atomic_update(struct drm_plane *plane,
>>  		height = state->src_h >> 16;
>>  		cpp = state->fb->format->cpp[0];
>> 
>>  -		if (priv->soc_info->has_osd && plane->type == 
>> DRM_PLANE_TYPE_OVERLAY)
>>  +		if (!priv->soc_info->has_osd || plane->type == 
>> DRM_PLANE_TYPE_OVERLAY)
>>  			hwdesc = &priv->dma_hwdescs->hwdesc_f0;
>>  		else
>>  			hwdesc = &priv->dma_hwdescs->hwdesc_f1;
> 
> we just replace this with
> 
>                 if (priv->soc_info->has_osd && plane->type != 
> DRM_PLANE_TYPE_OVERLAY)
>                         hwdesc = &priv->dma_hwdescs->hwdesc_f1;
>                 else
>                         hwdesc = &priv->dma_hwdescs->hwdesc_f0;
> 
> and the remainder can stay as is.
> 
>>  @@ -826,6 +826,7 @@ static int ingenic_drm_bind(struct device *dev, 
>> bool has_components)
>>  	const struct jz_soc_info *soc_info;
>>  	struct ingenic_drm *priv;
>>  	struct clk *parent_clk;
>>  +	struct drm_plane *primary;
>>  	struct drm_bridge *bridge;
>>  	struct drm_panel *panel;
>>  	struct drm_encoder *encoder;
>>  @@ -940,9 +941,11 @@ static int ingenic_drm_bind(struct device 
>> *dev, bool has_components)
>>  	if (soc_info->has_osd)
>>  		priv->ipu_plane = drm_plane_from_index(drm, 0);
>> 
>>  -	drm_plane_helper_add(&priv->f1, &ingenic_drm_plane_helper_funcs);
>>  +	primary = priv->soc_info->has_osd ? &priv->f1 : &priv->f0;
>> 
>>  -	ret = drm_universal_plane_init(drm, &priv->f1, 1,
>>  +	drm_plane_helper_add(primary, &ingenic_drm_plane_helper_funcs);
>>  +
>>  +	ret = drm_universal_plane_init(drm, primary, 1,
>>  				       &ingenic_drm_primary_plane_funcs,
>>  				       priv->soc_info->formats_f1,
>>  				       priv->soc_info->num_formats_f1,
>>  @@ -954,7 +957,7 @@ static int ingenic_drm_bind(struct device *dev, 
>> bool has_components)
>> 
>>  	drm_crtc_helper_add(&priv->crtc, &ingenic_drm_crtc_helper_funcs);
>> 
>>  -	ret = drm_crtc_init_with_planes(drm, &priv->crtc, &priv->f1,
>>  +	ret = drm_crtc_init_with_planes(drm, &priv->crtc, primary,
>>  					NULL, &ingenic_drm_crtc_funcs, NULL);
>>  	if (ret) {
>>  		dev_err(dev, "Failed to init CRTC: %i\n", ret);
>>  --
>>  2.29.2
>> 
> 
> BR and thanks,
> Nikolaus
>