Hi Marek,
On 9/1/2025 6:25 PM, Marek Szyprowski wrote:
On 01.09.2025 05:41, Damon Ding wrote:
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);
It is better. Now the display panel is detected and reported to
userspace, but it looks that something is not properly initialized,
because there is garbage instead of the proper picture.
I simulated the display path mentioned above on my RK3588S EVB1 Board.
To my slight surprise, it displayed normally with the reported connector
type DRM_MODE_CONNECTOR_LVDS. ;-)
The modifications included:
1.Synchronized the Analogix DP ralated DT configurations with Samsung
Snow Chromebook.
2.Skipped the I2C transfers and GPIO operations in nxp-ptn3460 driver.
3.Set the EDID to that of eDP Panel LP079QX1-SP0V forcibly.
Additionally, I added debug logs to verify whether the functions in
ptn3460_bridge_funcs were actually called.
Did you encounter any unexpected logs during your investigation? I'd
like to perform additional tests on this issue. :-)
Best regards,
Damon
diff --git a/arch/arm64/boot/dts/rockchip/rk3588s-evb1-v10.dts b/arch/arm64/boot/dts/rockchip/rk3588s-evb1-v10.dts
index 0df3e80f2dd9..51ce63fce6ee 100644
--- a/arch/arm64/boot/dts/rockchip/rk3588s-evb1-v10.dts
+++ b/arch/arm64/boot/dts/rockchip/rk3588s-evb1-v10.dts
@@ -26,6 +26,18 @@ chosen {
stdout-path = "serial2:1500000n8";
};
+ panel: panel {
+ compatible = "auo,b116xw03";
+ power-supply = <&vcc3v3_lcd_edp>;
+ backlight = <&backlight>;
+
+ port {
+ panel_in: endpoint {
+ remote-endpoint = <&bridge_out>;
+ };
+ };
+ };
+
adc-keys {
compatible = "adc-keys";
io-channels = <&saradc 1>;
@@ -242,21 +254,6 @@ &combphy2_psu {
&edp0 {
force-hpd;
status = "okay";
-
- aux-bus {
- panel {
- compatible = "edp-panel";
- backlight = <&backlight>;
- power-supply = <&vcc3v3_lcd_edp>;
- no-hpd;
-
- port {
- panel_in_edp: endpoint {
- remote-endpoint = <&edp_out_panel>;
- };
- };
- };
- };
};
&edp0_in {
@@ -266,8 +263,8 @@ edp0_in_vp2: endpoint {
};
&edp0_out {
- edp_out_panel: endpoint {
- remote-endpoint = <&panel_in_edp>;
+ dp_out: endpoint {
+ remote-endpoint = <&bridge_in>;
};
};
@@ -290,6 +287,33 @@ es8388: audio-codec@11 {
PVDD-supply = <&vcc_3v3_s0>;
#sound-dai-cells = <0>;
};
+
+ ptn3460: lvds-bridge@20 {
+ compatible = "nxp,ptn3460";
+ reg = <0x20>;
+ edid-emulation = <5>;
+
+ ports {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ port@0 {
+ reg = <0>;
+
+ bridge_out: endpoint {
+ remote-endpoint = <&panel_in>;
+ };
+ };
+
+ port@1 {
+ reg = <1>;
+
+ bridge_in: endpoint {
+ remote-endpoint = <&dp_out>;
+ };
+ };
+ };
+ };
};
&i2c8 {
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);
diff --git a/drivers/gpu/drm/bridge/nxp-ptn3460.c b/drivers/gpu/drm/bridge/nxp-ptn3460.c
index 7acb11f16dc1..cafbdcda2d29 100644
--- a/drivers/gpu/drm/bridge/nxp-ptn3460.c
+++ b/drivers/gpu/drm/bridge/nxp-ptn3460.c
@@ -52,6 +52,7 @@ static int ptn3460_read_bytes(struct ptn3460_bridge *ptn_bridge, char addr,
{
int ret;
+ return 0;
ret = i2c_master_send(ptn_bridge->client, &addr, 1);
if (ret < 0) {
DRM_ERROR("Failed to send i2c command, ret=%d\n", ret);
@@ -90,6 +91,7 @@ static int ptn3460_select_edid(struct ptn3460_bridge *ptn_bridge)
int ret;
char val;
+ return 0;
/* Load the selected edid into SRAM (accessed at PTN3460_EDID_ADDR) */
ret = ptn3460_write_byte(ptn_bridge, PTN3460_EDID_SRAM_LOAD_ADDR,
ptn_bridge->edid_emulation);
@@ -152,6 +154,21 @@ static void ptn3460_disable(struct drm_bridge *bridge)
gpiod_set_value(ptn_bridge->gpio_pd_n, 0);
}
+static const u8 edid_data[] = {
+ 0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x00, 0x16, 0x83,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x04, 0x17, 0x01, 0x00,
+ 0xA5, 0x10, 0x0C, 0x78, 0x06, 0xEF, 0x05, 0xA3, 0x54, 0x4C,
+ 0x99, 0x26, 0x0F, 0x50, 0x54, 0x00, 0x00, 0x00, 0x01, 0x01,
+ 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
+ 0x01, 0x01, 0x01, 0x01, 0xEA, 0x4E, 0x00, 0x4C, 0x60, 0x00,
+ 0x14, 0x80, 0x0C, 0x10, 0x84, 0x00, 0x78, 0xA0, 0x00, 0x00,
+ 0x00, 0x18, 0x00, 0x00, 0x00, 0x10, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0xFE, 0x00, 0x4C, 0x50, 0x30, 0x37, 0x39,
+ 0x51, 0x58, 0x31, 0x2D, 0x53, 0x50, 0x30, 0x56, 0x00, 0x00,
+ 0x00, 0xFC, 0x00, 0x43, 0x6F, 0x6C, 0x6F, 0x72, 0x20, 0x4C,
+ 0x43, 0x44, 0x0A, 0x20, 0x20, 0x20, 0x00, 0x3F
+};
static const struct drm_edid *ptn3460_edid_read(struct drm_bridge *bridge,
struct drm_connector *connector)
@@ -178,7 +195,8 @@ static const struct drm_edid *ptn3460_edid_read(struct drm_bridge *bridge,
goto out;
}
- drm_edid = drm_edid_alloc(edid, EDID_LENGTH);
+ kfree(edid);
+ drm_edid = drm_edid_alloc(edid_data, EDID_LENGTH);
out:
if (power_off)
@@ -273,7 +291,7 @@ static int ptn3460_probe(struct i2c_client *client)
ptn_bridge->panel_bridge = panel_bridge;
ptn_bridge->client = client;
- ptn_bridge->gpio_pd_n = devm_gpiod_get(&client->dev, "powerdown",
+ ptn_bridge->gpio_pd_n = devm_gpiod_get_optional(&client->dev, "powerdown",
GPIOD_OUT_HIGH);
if (IS_ERR(ptn_bridge->gpio_pd_n)) {
ret = PTR_ERR(ptn_bridge->gpio_pd_n);
@@ -285,7 +303,7 @@ static int ptn3460_probe(struct i2c_client *client)
* Request the reset pin low to avoid the bridge being
* initialized prematurely
*/
- ptn_bridge->gpio_rst_n = devm_gpiod_get(&client->dev, "reset",
+ ptn_bridge->gpio_rst_n = devm_gpiod_get_optional(&client->dev, "reset",
GPIOD_OUT_LOW);
if (IS_ERR(ptn_bridge->gpio_rst_n)) {
ret = PTR_ERR(ptn_bridge->gpio_rst_n);
diff --git a/drivers/gpu/drm/exynos/exynos_dp.c b/drivers/gpu/drm/exynos/exynos_dp.c
index 80ba700d2964..d0422f940249 100644
--- a/drivers/gpu/drm/exynos/exynos_dp.c
+++ b/drivers/gpu/drm/exynos/exynos_dp.c
@@ -104,7 +104,7 @@ static int exynos_dp_bridge_attach(struct analogix_dp_plat_data *plat_data,
/* Pre-empt DP connector creation if there's a bridge */
if (plat_data->next_bridge) {
ret = drm_bridge_attach(&dp->encoder, plat_data->next_bridge, bridge,
- 0);
+ DRM_BRIDGE_ATTACH_NO_CONNECTOR);
if (ret)
return ret;
}
