Hi Marek,
On 8/29/2025 4:23 PM, Marek Szyprowski wrote:
On 29.08.2025 10:08, Damon Ding wrote:
On 8/20/2025 5:20 AM, Marek Szyprowski wrote:
On 15.08.2025 04:59, Damon Ding wrote:
On 2025/8/15 5:16, Marek Szyprowski wrote:
On 14.08.2025 16:33, Marek Szyprowski wrote:
On 14.08.2025 12:47, Damon Ding wrote:
PATCH 1 is a small format optimization for struct
analogid_dp_device.
PATCH 2 is to perform mode setting in
&drm_bridge_funcs.atomic_enable.
PATCH 3-6 are preparations for apply drm_bridge_connector helper.
PATCH 7 is to apply the drm_bridge_connector helper.
PATCH 8-10 are to move the panel/bridge parsing to the Analogix
side.
PATCH 11-12 are preparations for apply panel_bridge helper.
PATCH 13 is to apply the panel_bridge helper.
This series lacks 'select DRM_BRIDGE_CONNECTOR' in ExynosDP's
Kconfig,
so it causes build break:
drivers/gpu/drm/exynos/exynos_dp.c:177: undefined reference to
`drm_bridge_connector_init'
make[2]: *** [scripts/Makefile.vmlinux:91: vmlinux] Error 1
After adding this dependency, the Exynos DP driver stops working. On
Samsung Snow Chromebook I observed following issue:
[ 4.534220] exynos-dp 145b0000.dp-controller: failed to attach
following panel or bridge (-16)
[ 4.543428] exynos-drm exynos-drm: failed to bind
145b0000.dp-controller (ops exynos_dp_ops): -16
[ 4.551775] exynos-drm exynos-drm: adev bind failed: -16
[ 4.556559] exynos-dp 145b0000.dp-controller: probe with driver
exynos-dp failed with error -16
I will investigate details later in the evening.
The failure is caused by trying to add plat_data->next_bridge twice
(from exynos_dp's .attach callback, and from analogix' ->bind
callback).
Best regards
I see. The bridge attachment for the next bridge was not well thought
out. It may be better to move panel_bridge addition a little forward
and remove next_bridge attachment on the Analogix side. Then, the
Rockchip side and Exynos side can do their own next_bridge attachment
in &analogix_dp_plat_data.attach() as they want.
Could you please help test the following modifications(they have been
tested on my RK3588S EVB1 Board) on the Samsung Snow Chromebook? ;-)
Assuming that I properly applied the malformed diff, it doesn't solve
all the issues. There are no errors reported though, but the display
chain doesn't work and no valid mode is reported:
# dmesg | grep drm
[ 3.384992] [drm] Initialized panfrost 1.4.0 for 11800000.gpu on
minor 0
[ 4.487739] [drm] Exynos DRM: using 14400000.fimd device for DMA
mapping operations
[ 4.494202] exynos-drm exynos-drm: bound 14400000.fimd (ops
fimd_component_ops)
[ 4.502374] exynos-drm exynos-drm: bound 14450000.mixer (ops
mixer_component_ops)
[ 4.511930] exynos-drm exynos-drm: bound 145b0000.dp-controller (ops
exynos_dp_ops)
[ 4.518411] exynos-drm exynos-drm: bound 14530000.hdmi (ops
hdmi_component_ops)
[ 4.529628] [drm] Initialized exynos 1.1.0 for exynos-drm on minor 1
[ 4.657434] exynos-drm exynos-drm: [drm] Cannot find any crtc or
sizes
[ 4.925023] exynos-drm exynos-drm: [drm] Cannot find any crtc or
sizes
# ./modetest -c -Mexynos
Connectors:
id encoder status name size (mm) modes
encoders
69 0 disconnected LVDS-1 0x0 0
68
props:
1 EDID:
flags: immutable blob
blobs:
value:
2 DPMS:
flags: enum
enums: On=0 Standby=1 Suspend=2 Off=3
value: 0
5 link-status:
flags: enum
enums: Good=0 Bad=1
value: 0
6 non-desktop:
flags: immutable range
values: 0 1
value: 0
4 TILE:
flags: immutable blob
blobs:
value:
71 0 disconnected HDMI-A-1 0x0 0
70
props:
1 EDID:
flags: immutable blob
blobs:
value:
2 DPMS:
flags: enum
enums: On=0 Standby=1 Suspend=2 Off=3
value: 0
5 link-status:
flags: enum
enums: Good=0 Bad=1
value: 0
6 non-desktop:
flags: immutable range
values: 0 1
value: 0
4 TILE:
flags: immutable blob
blobs:
value:
I will investigate details later this week.
Could you please provide the related DTS file for the test? I will
also try to find out the reason for this unexpected issue. ;-)
Unfortunately I didn't find enough time to debug this further. The above
log is from Samsung Snow Chromebook,
arch/arm/boot/dts/samsung/exynos5250-snow.dts
I compare the differences in the following display path before and after
this patch series:
exynos_dp -> nxp-ptn3460 -> panel "auo,b116xw03"
The issue is likely caused by the &drm_connector_funcs.detect() related
logic. Before this patch series, the nxp-ptn3460 connector is always
connector_status_connected because there is not available
&drm_connector_funcs.detect(). After it, the DRM_BRIDGE_OP_DETECT flag
make the connection status depend on analogix_dp_bridge_detect().
Could you please add the following patches additionally and try again?
(Not the final solution, just validation)
diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
index a93ff8f0a468..355911c47354 100644
--- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
+++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
@@ -1491,9 +1491,11 @@ int analogix_dp_bind(struct analogix_dp_device
*dp, struct drm_device *drm_dev)
}
}
- bridge->ops = DRM_BRIDGE_OP_DETECT |
- DRM_BRIDGE_OP_EDID |
+ bridge->ops = DRM_BRIDGE_OP_EDID |
DRM_BRIDGE_OP_MODES;
+ if (drm_bridge_is_panel(dp->plat_data->next_bridge))
+ bridge->ops |= DRM_BRIDGE_OP_DETECT;
+
bridge->of_node = dp->dev->of_node;
bridge->type = DRM_MODE_CONNECTOR_eDP;
ret = devm_drm_bridge_add(dp->dev, &dp->bridge);
Best regards,
Damon
