Re: [PATCH v1] drm/msm/dp: correct configure Colorimetry Indicator Field at MISC0

From: Kuogee Hsieh
Date: Thu Jan 11 2024 - 16:35:55 EST


On 1/10/2024 3:38 PM, Dmitry Baryshkov wrote:
On Wed, 10 Jan 2024 at 22:18, Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx> wrote:
MSA MISC0 bit 1 to 7 contains Colorimetry Indicator Field. At current
implementation, Colorimetry Indicator Field of MISC0 is not configured
correctly. This patch add support of RGB formats Colorimetry.
https://docs.kernel.org/process/submitting-patches.html#describe-your-changes

Also the commit message doesn't provide any details or what was incorrect.

Fixes: c943b4948b58 ("drm/msm/dp: add displayPort driver support")
Signed-off-by: Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx>
---
drivers/gpu/drm/msm/dp/dp_ctrl.c | 5 ++--
drivers/gpu/drm/msm/dp/dp_link.c | 26 ++++++++++++++++-----
drivers/gpu/drm/msm/dp/dp_panel.c | 48 +++++++++++++++++++++++++++++++++++++++
drivers/gpu/drm/msm/dp/dp_panel.h | 2 ++
4 files changed, 73 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c
index 77a8d93..2ef89fb 100644
--- a/drivers/gpu/drm/msm/dp/dp_ctrl.c
+++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c
@@ -1,6 +1,7 @@
// SPDX-License-Identifier: GPL-2.0-only
/*
- * Copyright (c) 2012-2020, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2012-2023, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2023-2024, Qualcomm Innovation Center, Inc. All rights reserved
*/

#define pr_fmt(fmt) "[drm-dp] %s: " fmt, __func__
@@ -172,7 +173,7 @@ static void dp_ctrl_configure_source_params(struct dp_ctrl_private *ctrl)

tb = dp_link_get_test_bits_depth(ctrl->link,
ctrl->panel->dp_mode.bpp);
- cc = dp_link_get_colorimetry_config(ctrl->link);
+ cc = dp_panel_get_misc_colorimetry_val(ctrl->panel);
dp_catalog_ctrl_config_misc(ctrl->catalog, cc, tb);
dp_panel_timing_cfg(ctrl->panel);
}
diff --git a/drivers/gpu/drm/msm/dp/dp_link.c b/drivers/gpu/drm/msm/dp/dp_link.c
index 98427d4..21fa1a2 100644
--- a/drivers/gpu/drm/msm/dp/dp_link.c
+++ b/drivers/gpu/drm/msm/dp/dp_link.c
@@ -1,6 +1,7 @@
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2012-2020, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2023-2024, Qualcomm Innovation Center, Inc. All rights reserved
*/

#define pr_fmt(fmt) "[drm-dp] %s: " fmt, __func__
@@ -12,6 +13,11 @@

#define DP_TEST_REQUEST_MASK 0x7F

+enum dynamic_range {
+ DP_DYNAMIC_RANGE_RGB_VESA,
+ DP_DYNAMIC_RANGE_RGB_CEA,
+};
+
enum audio_sample_rate {
AUDIO_SAMPLE_RATE_32_KHZ = 0x00,
AUDIO_SAMPLE_RATE_44_1_KHZ = 0x01,
@@ -1083,6 +1089,7 @@ int dp_link_process_request(struct dp_link *dp_link)
int dp_link_get_colorimetry_config(struct dp_link *dp_link)
{
u32 cc;
+ enum dynamic_range dr;
struct dp_link_private *link;

if (!dp_link) {
@@ -1092,14 +1099,21 @@ int dp_link_get_colorimetry_config(struct dp_link *dp_link)

link = container_of(dp_link, struct dp_link_private, dp_link);

- /*
- * Unless a video pattern CTS test is ongoing, use RGB_VESA
- * Only RGB_VESA and RGB_CEA supported for now
- */
+ /* unless a video pattern CTS test is ongoing, use CEA_VESA */
if (dp_link_is_video_pattern_requested(link))
- cc = link->dp_link.test_video.test_dyn_range;
+ dr = link->dp_link.test_video.test_dyn_range;
test_dyn_range has the value of (dpcd[DP_TEST_MISC0] &
DP_TEST_DYNAMIC_RANGE_CEA), so it can not be assigned to dr.

I don't feel like this has been tested.

yes, you are correct.

This code derived from down stream code.

I will fix it.

else
- cc = DP_TEST_DYNAMIC_RANGE_VESA;
+ dr = DP_DYNAMIC_RANGE_RGB_VESA;
+
+ /* Only RGB_VESA and RGB_CEA supported for now */
+ switch (dr) {
+ case DP_DYNAMIC_RANGE_RGB_CEA:
+ cc = BIT(2);
No undefined magic, please.

+ break;
+ case DP_DYNAMIC_RANGE_RGB_VESA:
+ default:
+ cc = 0;
+ }

return cc;
}
diff --git a/drivers/gpu/drm/msm/dp/dp_panel.c b/drivers/gpu/drm/msm/dp/dp_panel.c
index 127f6af..785bb59 100644
--- a/drivers/gpu/drm/msm/dp/dp_panel.c
+++ b/drivers/gpu/drm/msm/dp/dp_panel.c
@@ -1,6 +1,7 @@
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2012-2020, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2023-2024, Qualcomm Innovation Center, Inc. All rights reserved
*/

#include "dp_panel.h"
@@ -386,6 +387,53 @@ int dp_panel_init_panel_info(struct dp_panel *dp_panel)
return 0;
}

+/*
+ * Mapper function which outputs colorimetry to be used for a
+ * given colorspace value when misc field of MSA is used to
+ * change the colorimetry. Currently only RGB formats have been
+ * added. This API will be extended to YUV once it's supported on DP.
+ */
+u8 dp_panel_get_misc_colorimetry_val(struct dp_panel *dp_panel)
+{
+ u8 colorimetry;
+ u32 colorspace;
+ u32 cc;
+ struct dp_panel_private *panel;
+
+ panel = container_of(dp_panel, struct dp_panel_private, dp_panel);
+
+ cc = dp_link_get_colorimetry_config(panel->link);
+ /*
+ * If there is a non-zero value then compliance test-case
+ * is going on, otherwise we can honor the colorspace setting
+ */
+ if (cc)
+ return cc;
+
+ colorspace = dp_panel->connector->state->colorspace;
The driver doesn't attach the colorspace property, so this part is
useless. Anyway, I think adding colorimetry support will require more
changes than just setting the register in the DisplayPort controller.

agree,

this is just provision here for the future.

most likely, dp_panel->connector->state->colorspace will have value of 0 which will return colorimetry = 0 (legacy rgb mode) at end of this function.


+ drm_dbg_dp(panel->drm_dev, "colorspace=%d\n", colorspace);
+
+ switch (colorspace) {
+ case DRM_MODE_COLORIMETRY_DCI_P3_RGB_D65:
+ case DRM_MODE_COLORIMETRY_DCI_P3_RGB_THEATER:
+ colorimetry = 0x7;
+ break;
+ case DRM_MODE_COLORIMETRY_RGB_WIDE_FIXED:
+ colorimetry = 0x3;
+ break;
+ case DRM_MODE_COLORIMETRY_RGB_WIDE_FLOAT:
+ colorimetry = 0xb;
+ break;
+ case DRM_MODE_COLORIMETRY_OPRGB:
+ colorimetry = 0xc;
Please define these magic values.

+ break;
+ default:
+ colorimetry = 0; /* legacy RGB mode */
+ }
+
+ return colorimetry;
+}
+
struct dp_panel *dp_panel_get(struct dp_panel_in *in)
{
struct dp_panel_private *panel;
diff --git a/drivers/gpu/drm/msm/dp/dp_panel.h b/drivers/gpu/drm/msm/dp/dp_panel.h
index a0dfc57..c34a51d 100644
--- a/drivers/gpu/drm/msm/dp/dp_panel.h
+++ b/drivers/gpu/drm/msm/dp/dp_panel.h
@@ -1,6 +1,7 @@
/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (c) 2012-2020, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2023-2024, Qualcomm Innovation Center, Inc. All rights reserved
*/

#ifndef _DP_PANEL_H_
@@ -65,6 +66,7 @@ int dp_panel_get_modes(struct dp_panel *dp_panel,
struct drm_connector *connector);
void dp_panel_handle_sink_request(struct dp_panel *dp_panel);
void dp_panel_tpg_config(struct dp_panel *dp_panel, bool enable);
+u8 dp_panel_get_misc_colorimetry_val(struct dp_panel *dp_panel);

/**
* is_link_rate_valid() - validates the link rate
--
2.7.4