Re: [PATCH 00/22] drm: Convert drivers to drm_simple_encoder_init()

[Laurent Pinchart <laurent.pinchart-ryLnwIuWjnjg/C1BVhZhaw@public.gmane.org>]

Hi Thomas,

Thank you for the patch.

On Thu, Mar 05, 2020 at 04:59:28PM +0100, Thomas Zimmermann wrote:
> A call to drm_simple_encoder_init() initializes an encoder without
> further functionality. It only provides the destroy callback to
> cleanup the encoder's state. Only few drivers implement more
> sophisticated encoders than that. Most drivers implement such a
> simple encoder and can use drm_simple_encoder_init() instead.
> 
> The patchset converts drivers where the encoder's instance is
> embedded in a larger data structure. The driver releases the
> memory during cleanup. Each patch replaces drm_encoder_init() with
> drm_simple_encoder_init() and removes the (now unused) driver's
> encoder functions.
> 
> While the patchset is fairly large, the indiviual patches are self-
> contained and can be merged independently from each other. The
> simple-encoder functionality is currently in drm-misc-next, where
> these patches could go as well.

I've reviewed the whole series, including verifying that the few
instances of struct drm_encoder_funcs that were not declared const were
not modified somewhere to add more function pointers.

Reviewed-by: Laurent Pinchart <laurent.pinchart-ryLnwIuWjnjg/C1BVhZhaw@public.gmane.org>

for all the patches.

However, I'd like to note that drm_simple_encoder_init() is a bit of a
misnommer here. Several of the encoders in those drivers to implement
additional functionality. They just expose them through
drm_encoder_helper_funcs, not drm_encoder_funcs.

> Future directions: There's another common case where the driver
> calls kzalloc() plus drm_encoder_init(). Such drivers are not
> handled by this patchset. The plan here is to use a simple encoder
> with either managed memory allocation (once it's merged), or embed
> the encoder in a larger data structure and drop kzalloc() entirely.

I think an even more interesting future enhancement would be to add
encoder support to the newly added drm_bridge_connector_init(), for
drivers that are fully based on bridges and don't implement any encoder
operation, neither through drm_encoder_funcs nor through
drm_encoder_helper_funcs.

> The patchset has been compile-tested on x86-64, aarch64 and arm.
> 
> Thomas Zimmermann (22):
>   drm/arc: Use simple encoder
>   drm/atmel-hlcdc: Use simple encoder
>   drm/exynos: Use simple encoder
>   drm/fsl-dcu: Use simple encoder
>   drm/gma500: Use simple encoder
>   drm/hisilicon/kirin: Use simple encoder
>   drm/i2c/tda998x: Use simple encoder
>   drm/imx: Use simple encoder
>   drm/ingenic: Use simple encoder
>   drm/mediatek: Use simple encoder
>   drm/rcar-du: Use simple encoder
>   drm/rockchip: Use simple encoder
>   drm/shmobile: Use simple encoder
>   drm/sun4i: Use simple encoder
>   drm/tegra: Use simple encoder
>   drm/tidss: Use simple encoder
>   drm/tilcdc: Use simple encoder
>   drm/vc4: Use simple encoder
>   drm/virtgpu: Use simple encoder
>   drm/vkms: Use simple encoder
>   drm/writeback: Use simple encoder
>   drm/zte: Use simple encoder
> 
>  drivers/gpu/drm/arc/arcpgu_hdmi.c              | 10 +++-------
>  drivers/gpu/drm/arc/arcpgu_sim.c               |  8 ++------
>  .../gpu/drm/atmel-hlcdc/atmel_hlcdc_output.c   | 12 ++++--------
>  drivers/gpu/drm/drm_writeback.c                | 10 +++-------
>  drivers/gpu/drm/exynos/exynos_dp.c             |  8 ++------
>  drivers/gpu/drm/exynos/exynos_drm_dpi.c        |  8 ++------
>  drivers/gpu/drm/exynos/exynos_drm_dsi.c        |  8 ++------
>  drivers/gpu/drm/exynos/exynos_drm_vidi.c       |  8 ++------
>  drivers/gpu/drm/exynos/exynos_hdmi.c           |  8 ++------
>  drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_rgb.c      | 14 +++-----------
>  drivers/gpu/drm/gma500/cdv_intel_crt.c         | 14 +++-----------
>  drivers/gpu/drm/gma500/cdv_intel_dp.c          | 16 +++-------------
>  drivers/gpu/drm/gma500/cdv_intel_hdmi.c        |  4 ++--
>  drivers/gpu/drm/gma500/cdv_intel_lvds.c        | 17 +++--------------
>  drivers/gpu/drm/gma500/mdfld_dsi_dpi.c         |  7 +++----
>  drivers/gpu/drm/gma500/mdfld_output.h          |  1 -
>  drivers/gpu/drm/gma500/mdfld_tmd_vid.c         |  6 ------
>  drivers/gpu/drm/gma500/mdfld_tpo_vid.c         |  6 ------
>  drivers/gpu/drm/gma500/oaktrail_hdmi.c         | 14 ++------------
>  drivers/gpu/drm/gma500/oaktrail_lvds.c         |  5 +++--
>  drivers/gpu/drm/gma500/psb_intel_drv.h         |  1 -
>  drivers/gpu/drm/gma500/psb_intel_lvds.c        | 18 +++---------------
>  drivers/gpu/drm/gma500/tc35876x-dsi-lvds.c     |  5 -----
>  drivers/gpu/drm/hisilicon/kirin/dw_drm_dsi.c   |  8 ++------
>  drivers/gpu/drm/i2c/tda998x_drv.c              | 14 +++-----------
>  drivers/gpu/drm/imx/dw_hdmi-imx.c              |  8 ++------
>  drivers/gpu/drm/imx/imx-drm-core.c             |  6 ------
>  drivers/gpu/drm/imx/imx-drm.h                  |  1 -
>  drivers/gpu/drm/imx/imx-ldb.c                  |  8 ++------
>  drivers/gpu/drm/imx/imx-tve.c                  |  8 ++------
>  drivers/gpu/drm/imx/parallel-display.c         |  8 ++------
>  drivers/gpu/drm/ingenic/ingenic-drm.c          |  9 +++------
>  drivers/gpu/drm/mediatek/mtk_dpi.c             | 14 +++-----------
>  drivers/gpu/drm/mediatek/mtk_dsi.c             | 14 +++-----------
>  drivers/gpu/drm/rcar-du/rcar_du_encoder.c      | 14 +++-----------
>  .../gpu/drm/rockchip/analogix_dp-rockchip.c    |  9 +++------
>  drivers/gpu/drm/rockchip/cdn-dp-core.c         |  9 +++------
>  .../gpu/drm/rockchip/dw-mipi-dsi-rockchip.c    |  8 ++------
>  drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c    |  8 ++------
>  drivers/gpu/drm/rockchip/inno_hdmi.c           |  8 ++------
>  drivers/gpu/drm/rockchip/rk3066_hdmi.c         |  8 ++------
>  drivers/gpu/drm/rockchip/rockchip_lvds.c       | 10 +++-------
>  drivers/gpu/drm/rockchip/rockchip_rgb.c        |  8 ++------
>  drivers/gpu/drm/shmobile/shmob_drm_crtc.c      | 14 +++-----------
>  drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c         | 12 +++---------
>  drivers/gpu/drm/sun4i/sun4i_lvds.c             | 12 +++---------
>  drivers/gpu/drm/sun4i/sun4i_rgb.c              | 17 +++--------------
>  drivers/gpu/drm/sun4i/sun4i_tv.c               | 17 +++--------------
>  drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c         | 12 +++---------
>  drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c          |  8 ++------
>  drivers/gpu/drm/tegra/drm.h                    |  2 --
>  drivers/gpu/drm/tegra/dsi.c                    | 10 +++-------
>  drivers/gpu/drm/tegra/hdmi.c                   |  9 +++------
>  drivers/gpu/drm/tegra/output.c                 |  6 +-----
>  drivers/gpu/drm/tegra/rgb.c                    |  8 ++------
>  drivers/gpu/drm/tegra/sor.c                    |  8 ++------
>  drivers/gpu/drm/tidss/tidss_encoder.c          | 10 +++-------
>  drivers/gpu/drm/tilcdc/tilcdc_external.c       | 10 +++-------
>  drivers/gpu/drm/tilcdc/tilcdc_panel.c          |  8 ++------
>  drivers/gpu/drm/vc4/vc4_dpi.c                  |  8 ++------
>  drivers/gpu/drm/vc4/vc4_dsi.c                  | 15 +++------------
>  drivers/gpu/drm/vc4/vc4_hdmi.c                 | 17 ++++-------------
>  drivers/gpu/drm/vc4/vc4_vec.c                  |  8 ++------
>  drivers/gpu/drm/virtio/virtgpu_display.c       |  8 ++------
>  drivers/gpu/drm/vkms/vkms_output.c             |  8 ++------
>  drivers/gpu/drm/zte/zx_hdmi.c                  |  8 ++------
>  drivers/gpu/drm/zte/zx_tvenc.c                 |  8 ++------
>  drivers/gpu/drm/zte/zx_vga.c                   |  8 ++------
>  68 files changed, 151 insertions(+), 488 deletions(-)

-- 
Regards,

Laurent Pinchart