Re: [PATCH v3 04/11] drm/sun4i: abstract the layer type

From: Chen-Yu Tsai
Date: Mon Apr 03 2017 - 06:52:15 EST


On Mon, Apr 3, 2017 at 4:14 PM, Maxime Ripard
<maxime.ripard@xxxxxxxxxxxxxxxxxx> wrote:
> Hi,
>
> On Thu, Mar 30, 2017 at 03:46:06AM +0800, Icenowy Zheng wrote:
>> As we are going to add support for the Allwinner DE2 Mixer in sun4i-drm
>> driver, we will finally have two types of layer.
>>
>> Abstract the layer type to void * and a ops struct, which contains the
>> only function used by crtc -- get the drm_plane struct of the layer.
>>
>> Signed-off-by: Icenowy Zheng <icenowy@xxxxxxx>
>> ---
>> Refactored patch in v3.
>>
>> drivers/gpu/drm/sun4i/sun4i_crtc.c | 19 +++++++++++--------
>> drivers/gpu/drm/sun4i/sun4i_crtc.h | 3 ++-
>> drivers/gpu/drm/sun4i/sun4i_layer.c | 19 ++++++++++++++++++-
>> drivers/gpu/drm/sun4i/sun4i_layer.h | 2 +-
>> drivers/gpu/drm/sun4i/sunxi_layer.h | 17 +++++++++++++++++
>> 5 files changed, 49 insertions(+), 11 deletions(-)
>> create mode 100644 drivers/gpu/drm/sun4i/sunxi_layer.h
>>
>> diff --git a/drivers/gpu/drm/sun4i/sun4i_crtc.c b/drivers/gpu/drm/sun4i/sun4i_crtc.c
>> index 3c876c3a356a..33854ee7f636 100644
>> --- a/drivers/gpu/drm/sun4i/sun4i_crtc.c
>> +++ b/drivers/gpu/drm/sun4i/sun4i_crtc.c
>> @@ -29,6 +29,7 @@
>> #include "sun4i_crtc.h"
>> #include "sun4i_drv.h"
>> #include "sun4i_layer.h"
>> +#include "sunxi_layer.h"
>> #include "sun4i_tcon.h"
>>
>> static void sun4i_crtc_atomic_begin(struct drm_crtc *crtc,
>> @@ -149,7 +150,7 @@ struct sun4i_crtc *sun4i_crtc_init(struct drm_device *drm,
>> scrtc->tcon = tcon;
>>
>> /* Create our layers */
>> - scrtc->layers = sun4i_layers_init(drm, scrtc->backend);
>> + scrtc->layers = (void **)sun4i_layers_init(drm, scrtc);
>> if (IS_ERR(scrtc->layers)) {
>> dev_err(drm->dev, "Couldn't create the planes\n");
>> return NULL;
>> @@ -157,14 +158,15 @@ struct sun4i_crtc *sun4i_crtc_init(struct drm_device *drm,
>>
>> /* find primary and cursor planes for drm_crtc_init_with_planes */
>> for (i = 0; scrtc->layers[i]; i++) {
>> - struct sun4i_layer *layer = scrtc->layers[i];
>> + void *layer = scrtc->layers[i];
>> + struct drm_plane *plane = scrtc->layer_ops->get_plane(layer);
>>
>> - switch (layer->plane.type) {
>> + switch (plane->type) {
>> case DRM_PLANE_TYPE_PRIMARY:
>> - primary = &layer->plane;
>> + primary = plane;
>> break;
>> case DRM_PLANE_TYPE_CURSOR:
>> - cursor = &layer->plane;
>> + cursor = plane;
>> break;
>> default:
>> break;
>> @@ -190,10 +192,11 @@ struct sun4i_crtc *sun4i_crtc_init(struct drm_device *drm,
>> /* Set possible_crtcs to this crtc for overlay planes */
>> for (i = 0; scrtc->layers[i]; i++) {
>> uint32_t possible_crtcs = BIT(drm_crtc_index(&scrtc->crtc));
>> - struct sun4i_layer *layer = scrtc->layers[i];
>> + void *layer = scrtc->layers[i];
>> + struct drm_plane *plane = scrtc->layer_ops->get_plane(layer);
>>
>> - if (layer->plane.type == DRM_PLANE_TYPE_OVERLAY)
>> - layer->plane.possible_crtcs = possible_crtcs;
>> + if (plane->type == DRM_PLANE_TYPE_OVERLAY)
>> + plane->possible_crtcs = possible_crtcs;
>
> I think the logic should be reversed here, the CRTC shouldn't care
> (much) about the layers at all.

Correct. It shouldn't. However since the layers are tied to a specific
crtc, they get created as part of the crtc init sequence.

> We should modify sun4i_crtc_init to get the argument it needs (primary
> and cursor planes for example) through its parameters, and have the
> caller (which iirc is sun4i_drv) call it with the right parameters

The caller is (now) sun4i_crtc_init.

> depending on whether you're using DE or DE2.

Ack.

>
> If we're doing that, I don't think we even need the pointer to the
> array of layers in struct sun4i_crtc, which will make it easier to
> deal with.

Ack.

ChenYu