Re: [PATCH v2] drm: bridge: tc358764: Use drm panel_bridge API

Hi Jagan,

On 15.12.2021 13:59, Jagan Teki wrote:

On Wed, Dec 15, 2021 at 5:30 PM Marek Szyprowski
[off-list ref] wrote:

quoted

On 15.12.2021 11:04, Jagan Teki wrote:

quoted

Replace the manual panel handling code by a drm panel_bridge via
devm_drm_of_get_bridge().

Adding panel_bridge handling,

- Drops drm_connector and related operations as drm_bridge_attach
    creates connector during attachment.

- Drops panel pointer and panel healpers.

This simplifies the driver and allows all components in the display
pipeline to be treated as bridges.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>

I just tested it on top of linux-next with "drm: of: Lookup if child
node has panel or bridge" patch. Sadly it still doesn't work on
Exynos5250-based Arndale board:

OF: graph: no port node found in /soc/hdmi@14530000
[drm] Exynos DRM: using 14400000.fimd device for DMA mapping operations
exynos-drm exynos-drm: bound 14400000.fimd (ops fimd_component_ops)
exynos-drm exynos-drm: bound 14450000.mixer (ops mixer_component_ops)
OF: graph: no port node found in /soc/dsi@14500000
exynos-drm exynos-drm: bound 14500000.dsi (ops exynos_dsi_component_ops)
exynos-drm exynos-drm: bound 14530000.hdmi (ops hdmi_component_ops)
exynos-drm exynos-drm: [drm] Cannot find any crtc or sizes
exynos-drm exynos-drm: [drm] Cannot find any crtc or sizes
[drm] Initialized exynos 1.1.0 20180330 for exynos-drm on minor 0
panfrost 11800000.gpu: clock rate = 533000000
panfrost 11800000.gpu: mali-t600 id 0x600 major 0x0 minor 0x0 status 0x1
panfrost 11800000.gpu: features: 00000000,10206000, issues:
00000000,31b4dfff
panfrost 11800000.gpu: Features: L2:0x07110206 Shader:0x00000000
Tiler:0x00000809 Mem:0x1 MMU:0x00002830 AS:0xf JS:0x7
panfrost 11800000.gpu: shader_present=0xf l2_present=0x1
[drm] Initialized panfrost 1.2.0 20180908 for 11800000.gpu on minor 1
------------[ cut here ]------------
WARNING: CPU: 1 PID: 7 at drivers/gpu/drm/drm_atomic_state_helper.c:494
drm_atomic_helper_connector_duplicate_state+0x60/0x68

Known problem, it require 1/6 from Bridge conversation series. We can
move this patch into conversion series next time or while merging.

Indeed, with the 1/6 patch it works fine on Exynos5250 based Arndale board.

Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>

Best regards

-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland