From mboxrd@z Thu Jan 1 00:00:00 1970 From: icenowy@aosc.io (icenowy at aosc.io) Date: Thu, 06 Apr 2017 01:14:40 +0800 Subject: [linux-sunxi] Re: [PATCH v3 04/11] drm/sun4i: abstract the layer type In-Reply-To: References: <20170329194613.55548-1-icenowy@aosc.io> <20170329194613.55548-5-icenowy@aosc.io> <20170404192837.pvlhwyeut45vg2wg@art_vandelay> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org ? 2017-04-05 10:27?Chen-Yu Tsai ??? > On Wed, Apr 5, 2017 at 3:53 AM, Icenowy Zheng wrote: >> >> >> ? 2017?04?05? 03:28, Sean Paul ??: >>> >>> 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 >>>> --- >>>> 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; >>>> } >>>> >>>> return scrtc; >>>> diff --git a/drivers/gpu/drm/sun4i/sun4i_crtc.h >>>> b/drivers/gpu/drm/sun4i/sun4i_crtc.h >>>> index 230cb8f0d601..a4036ee44cf8 100644 >>>> --- a/drivers/gpu/drm/sun4i/sun4i_crtc.h >>>> +++ b/drivers/gpu/drm/sun4i/sun4i_crtc.h >>>> @@ -19,7 +19,8 @@ struct sun4i_crtc { >>>> >>>> struct sun4i_backend *backend; >>>> struct sun4i_tcon *tcon; >>>> - struct sun4i_layer **layers; >>>> + void **layers; >>>> + const struct sunxi_layer_ops *layer_ops; >>> >>> >>> I think you should probably take a different approach to abstract the >>> layer >>> type. How about creating >>> >>> struct sunxi_layer { >>> struct drm_plane plane; >>> } >>> >>> base and then subclassing that for sun4i and sun8i? By doing this you >>> can >>> avoid >>> the nasty casting and you can also get rid of the get_plane() hook >>> and >>> layer_ops. >> >> >> For the situation that using ** things are easily to get weird. > > That code could be reworked, by initializing the layers directly within > the crtc init code. If you look at rockchip's drm driver, you'll see > they do this. There is a good reason to do it this way, as you need > to first create the primary and cursor layers, pass them in when you > create the crtc, then initialize any additional layers with the > possible_crtcs bitmap. I feel that it's still more proper to offload plane creation code to *_layers_init function, as: 1. We cannot assume the cursor layer's existance. In fact currently no code in sun4i-drm (including this patchset) create a cursor layer. 2. The format of planes heavily depend on the engine type ( sun4i-backend or sun8i-mixer). 3. We should create planes according to the type of engine. Currently the *_layers_init function is part of engine code (See my Makefile change). 4. If we do so we will have two codes for plane creating -- one for primary in sun4i_crtc_init, another for overlays in *_layers_init. > > In our driver we are currently initializing all layers, then going > back and filling in possible_crtcs for the extra layers. > > And as Maxime and I mentioned in the other thread, we don't really > need to keep a reference to **layers. It's correct, layers doesn't need to be kept. And the struct sunxi_layer refactor also makes sense. > > Regards > ChenYu > >> >>> >>> Sean >>> >>> >>> >>>> }; >>>> >>>> static inline struct sun4i_crtc *drm_crtc_to_sun4i_crtc(struct >>>> drm_crtc >>>> *crtc) >>>> diff --git a/drivers/gpu/drm/sun4i/sun4i_layer.c >>>> b/drivers/gpu/drm/sun4i/sun4i_layer.c >>>> index f26bde5b9117..bc4a70d6968b 100644 >>>> --- a/drivers/gpu/drm/sun4i/sun4i_layer.c >>>> +++ b/drivers/gpu/drm/sun4i/sun4i_layer.c >>>> @@ -16,7 +16,9 @@ >>>> #include >>>> >>>> #include "sun4i_backend.h" >>>> +#include "sun4i_crtc.h" >>>> #include "sun4i_layer.h" >>>> +#include "sunxi_layer.h" >>>> >>>> struct sun4i_plane_desc { >>>> enum drm_plane_type type; >>>> @@ -100,6 +102,17 @@ static const struct sun4i_plane_desc >>>> sun4i_backend_planes[] = { >>>> }, >>>> }; >>>> >>>> +static struct drm_plane *sun4i_layer_get_plane(void *layer) >>>> +{ >>>> + struct sun4i_layer *sun4i_layer = layer; >>>> + >>>> + return &sun4i_layer->plane; >>>> +} >>>> + >>>> +static const struct sunxi_layer_ops layer_ops = { >>>> + .get_plane = sun4i_layer_get_plane, >>>> +}; >>>> + >>>> static struct sun4i_layer *sun4i_layer_init_one(struct drm_device >>>> *drm, >>>> struct sun4i_backend >>>> *backend, >>>> const struct >>>> sun4i_plane_desc *plane) >>>> @@ -129,9 +142,10 @@ static struct sun4i_layer >>>> *sun4i_layer_init_one(struct drm_device *drm, >>>> } >>>> >>>> struct sun4i_layer **sun4i_layers_init(struct drm_device *drm, >>>> - struct sun4i_backend >>>> *backend) >>>> + struct sun4i_crtc *crtc) >>>> { >>>> struct sun4i_layer **layers; >>>> + struct sun4i_backend *backend = crtc->backend; >>>> int i; >>>> >>>> layers = devm_kcalloc(drm->dev, >>>> ARRAY_SIZE(sun4i_backend_planes) >>>> + 1, >>>> @@ -181,5 +195,8 @@ struct sun4i_layer **sun4i_layers_init(struct >>>> drm_device *drm, >>>> layers[i] = layer; >>>> }; >>>> >>>> + /* Assign layer ops to the CRTC */ >>>> + crtc->layer_ops = &layer_ops; >>>> + >>>> return layers; >>>> } >>>> diff --git a/drivers/gpu/drm/sun4i/sun4i_layer.h >>>> b/drivers/gpu/drm/sun4i/sun4i_layer.h >>>> index 4be1f0919df2..425eea7b9e3b 100644 >>>> --- a/drivers/gpu/drm/sun4i/sun4i_layer.h >>>> +++ b/drivers/gpu/drm/sun4i/sun4i_layer.h >>>> @@ -27,6 +27,6 @@ plane_to_sun4i_layer(struct drm_plane *plane) >>>> } >>>> >>>> struct sun4i_layer **sun4i_layers_init(struct drm_device *drm, >>>> - struct sun4i_backend >>>> *backend); >>>> + struct sun4i_crtc *crtc); >>>> >>>> #endif /* _SUN4I_LAYER_H_ */ >>>> diff --git a/drivers/gpu/drm/sun4i/sunxi_layer.h >>>> b/drivers/gpu/drm/sun4i/sunxi_layer.h >>>> new file mode 100644 >>>> index 000000000000..d8838ec39299 >>>> --- /dev/null >>>> +++ b/drivers/gpu/drm/sun4i/sunxi_layer.h >>>> @@ -0,0 +1,17 @@ >>>> +/* >>>> + * Copyright (C) 2017 Icenowy Zheng >>>> + * >>>> + * This program is free software; you can redistribute it and/or >>>> + * modify it under the terms of the GNU General Public License as >>>> + * published by the Free Software Foundation; either version 2 of >>>> + * the License, or (at your option) any later version. >>>> + */ >>>> + >>>> +#ifndef _SUNXI_LAYER_H_ >>>> +#define _SUNXI_LAYER_H_ >>>> + >>>> +struct sunxi_layer_ops { >>>> + struct drm_plane *(*get_plane)(void *layer); >>>> +}; >>>> + >>>> +#endif /* _SUNXI_LAYER_H_ */ >>>> -- >>>> 2.12.0 >>>> >>>> >>>> _______________________________________________ >>>> linux-arm-kernel mailing list >>>> linux-arm-kernel at lists.infradead.org >>>> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel >>> >>> >> >> -- >> You received this message because you are subscribed to the Google >> Groups >> "linux-sunxi" group. >> To unsubscribe from this group and stop receiving emails from it, send >> an >> email to linux-sunxi+unsubscribe at googlegroups.com. >> For more options, visit https://groups.google.com/d/optout. > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel at lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel