[PATCH v16 4/4] drm/bridge: dw-hdmi: fix bus formats negotiation for 8 bit modes
Neil Armstrong
narmstrong at baylibre.com
Thu Mar 3 08:35:24 UTC 2022
Hi,
On 02/03/2022 23:24, H. Nikolaus Schaller wrote:
> Hi Neil,
>
>> Am 02.03.2022 um 15:34 schrieb Neil Armstrong <narmstrong at baylibre.com>:
>>
>> Hi,
>>
>>> (cross-checked: RGB mode still works if I force hdmi->sink_is_hdmi = false)
>>
>> I don't understand what's wrong, can you try to make the logic select MEDIA_BUS_FMT_YUV8_1X24 instead of DRM_COLOR_FORMAT_YCBCR422 ?
>
> I have forced hdmi->sink_is_hdmi = false and replaced
>
> /* Default 8bit RGB fallback */
> - output_fmts[i++] = MEDIA_BUS_FMT_RGB888_1X24;
> + output_fmts[i++] = MEDIA_BUS_FMT_YUV8_1X24;
>
> And then screen remains black. MEDIA_BUS_FMT_RGB888_1X24 works.
> (MEDIA_BUS_FMT_VUY8_1X24 doesn't work either).
>
> So this indicates that YUV conversion is not working properly. Maybe missing some special
> setup.
>
> What I have to test if it works on a different monitor. Not that this specific panel
> (a 7 inch waveshare touch with HDMIinput) is buggy and reports YUV capabilities
> but does not handle them...
>
> On the other hand this panel works on RasPi and OMAP5 (where I admit I do not know in
> which mode).
Pretty sure they don't support YUV HDMI output.
If you can try on a certified HDMI devices like a TV, it would here figuring out where comes the issue.
>
>> If your CSC is broken, we'll need to disable it on your platform.
>
> Indeed.
>
> So it seems as if we need a mechanism to overwrite dw_hdmi_bridge_atomic_get_output_bus_fmts()
> in our ingenic-dw-hdmi platform specialization [1] to always return MEDIA_BUS_FMT_RGB888_1X24.
>
> Or alternatively set sink_is_hdmi = false there (unfortunately there is no direct access to
> struct dw_hdmi in a specialization drivers).
>
> Is this already possible or how can it be done?
It's not handled yet, but we may add the logic to handle the lack of CSC config bit and
add a glue config bit to override this like we already did for CEC.
I wrote an initial support to disable CSC (only compile-tested), could you try on your platform with setting disable_csc = 1 in your dw-hdmi glue code ?
================><=======================================
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
index 54d8fdad395f..d345166a69aa 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
@@ -158,6 +158,8 @@ struct dw_hdmi {
struct hdmi_data_info hdmi_data;
const struct dw_hdmi_plat_data *plat_data;
+ bool csc_available; /* indicates if the CSC engine is usable */
+
int vic;
u8 edid[HDMI_EDID_LEN];
@@ -1009,9 +1011,10 @@ static int is_color_space_interpolation(struct dw_hdmi *hdmi)
static bool is_csc_needed(struct dw_hdmi *hdmi)
{
- return is_color_space_conversion(hdmi) ||
- is_color_space_decimation(hdmi) ||
- is_color_space_interpolation(hdmi);
+ return hdmi->csc_available &&
+ (is_color_space_conversion(hdmi) ||
+ is_color_space_decimation(hdmi) ||
+ is_color_space_interpolation(hdmi));
}
static void dw_hdmi_update_csc_coeffs(struct dw_hdmi *hdmi)
@@ -1064,6 +1067,9 @@ static void hdmi_video_csc(struct dw_hdmi *hdmi)
int interpolation = HDMI_CSC_CFG_INTMODE_DISABLE;
int decimation = 0;
+ if (!hdmi->csc_available)
+ return;
+
/* YCC422 interpolation to 444 mode */
if (is_color_space_interpolation(hdmi))
interpolation = HDMI_CSC_CFG_INTMODE_CHROMA_INT_FORMULA1;
@@ -2663,6 +2669,7 @@ static u32 *dw_hdmi_bridge_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
u32 output_fmt,
unsigned int *num_input_fmts)
{
+ struct dw_hdmi *hdmi = bridge->driver_private;
u32 *input_fmts;
unsigned int i = 0;
@@ -2681,62 +2688,81 @@ static u32 *dw_hdmi_bridge_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
/* 8bit */
case MEDIA_BUS_FMT_RGB888_1X24:
input_fmts[i++] = MEDIA_BUS_FMT_RGB888_1X24;
- input_fmts[i++] = MEDIA_BUS_FMT_YUV8_1X24;
- input_fmts[i++] = MEDIA_BUS_FMT_UYVY8_1X16;
+ if (hdmi->csc_available) {
+ input_fmts[i++] = MEDIA_BUS_FMT_YUV8_1X24;
+ input_fmts[i++] = MEDIA_BUS_FMT_UYVY8_1X16;
+ }
break;
case MEDIA_BUS_FMT_YUV8_1X24:
input_fmts[i++] = MEDIA_BUS_FMT_YUV8_1X24;
- input_fmts[i++] = MEDIA_BUS_FMT_UYVY8_1X16;
- input_fmts[i++] = MEDIA_BUS_FMT_RGB888_1X24;
+ if (hdmi->csc_available) {
+ input_fmts[i++] = MEDIA_BUS_FMT_UYVY8_1X16;
+ input_fmts[i++] = MEDIA_BUS_FMT_RGB888_1X24;
+ }
break;
case MEDIA_BUS_FMT_UYVY8_1X16:
input_fmts[i++] = MEDIA_BUS_FMT_UYVY8_1X16;
- input_fmts[i++] = MEDIA_BUS_FMT_YUV8_1X24;
- input_fmts[i++] = MEDIA_BUS_FMT_RGB888_1X24;
+ if (hdmi->csc_available) {
+ input_fmts[i++] = MEDIA_BUS_FMT_YUV8_1X24;
+ input_fmts[i++] = MEDIA_BUS_FMT_RGB888_1X24;
+ }
break;
/* 10bit */
case MEDIA_BUS_FMT_RGB101010_1X30:
input_fmts[i++] = MEDIA_BUS_FMT_RGB101010_1X30;
- input_fmts[i++] = MEDIA_BUS_FMT_YUV10_1X30;
- input_fmts[i++] = MEDIA_BUS_FMT_UYVY10_1X20;
+ if (hdmi->csc_available) {
+ input_fmts[i++] = MEDIA_BUS_FMT_YUV10_1X30;
+ input_fmts[i++] = MEDIA_BUS_FMT_UYVY10_1X20;
+ }
break;
case MEDIA_BUS_FMT_YUV10_1X30:
input_fmts[i++] = MEDIA_BUS_FMT_YUV10_1X30;
- input_fmts[i++] = MEDIA_BUS_FMT_UYVY10_1X20;
- input_fmts[i++] = MEDIA_BUS_FMT_RGB101010_1X30;
+ if (hdmi->csc_available) {
+ input_fmts[i++] = MEDIA_BUS_FMT_UYVY10_1X20;
+ input_fmts[i++] = MEDIA_BUS_FMT_RGB101010_1X30;
+ }
break;
case MEDIA_BUS_FMT_UYVY10_1X20:
input_fmts[i++] = MEDIA_BUS_FMT_UYVY10_1X20;
- input_fmts[i++] = MEDIA_BUS_FMT_YUV10_1X30;
- input_fmts[i++] = MEDIA_BUS_FMT_RGB101010_1X30;
+ if (hdmi->csc_available) {
+ input_fmts[i++] = MEDIA_BUS_FMT_YUV10_1X30;
+ input_fmts[i++] = MEDIA_BUS_FMT_RGB101010_1X30;
+ }
break;
/* 12bit */
case MEDIA_BUS_FMT_RGB121212_1X36:
input_fmts[i++] = MEDIA_BUS_FMT_RGB121212_1X36;
- input_fmts[i++] = MEDIA_BUS_FMT_YUV12_1X36;
- input_fmts[i++] = MEDIA_BUS_FMT_UYVY12_1X24;
+ if (hdmi->csc_available) {
+ input_fmts[i++] = MEDIA_BUS_FMT_YUV12_1X36;
+ input_fmts[i++] = MEDIA_BUS_FMT_UYVY12_1X24;
+ }
break;
case MEDIA_BUS_FMT_YUV12_1X36:
input_fmts[i++] = MEDIA_BUS_FMT_YUV12_1X36;
- input_fmts[i++] = MEDIA_BUS_FMT_UYVY12_1X24;
- input_fmts[i++] = MEDIA_BUS_FMT_RGB121212_1X36;
+ if (hdmi->csc_available) {
+ input_fmts[i++] = MEDIA_BUS_FMT_UYVY12_1X24;
+ input_fmts[i++] = MEDIA_BUS_FMT_RGB121212_1X36;
+ }
break;
case MEDIA_BUS_FMT_UYVY12_1X24:
input_fmts[i++] = MEDIA_BUS_FMT_UYVY12_1X24;
- input_fmts[i++] = MEDIA_BUS_FMT_YUV12_1X36;
- input_fmts[i++] = MEDIA_BUS_FMT_RGB121212_1X36;
+ if (hdmi->csc_available) {
+ input_fmts[i++] = MEDIA_BUS_FMT_YUV12_1X36;
+ input_fmts[i++] = MEDIA_BUS_FMT_RGB121212_1X36;
+ }
break;
/* 16bit */
case MEDIA_BUS_FMT_RGB161616_1X48:
input_fmts[i++] = MEDIA_BUS_FMT_RGB161616_1X48;
- input_fmts[i++] = MEDIA_BUS_FMT_YUV16_1X48;
+ if (hdmi->csc_available)
+ input_fmts[i++] = MEDIA_BUS_FMT_YUV16_1X48;
break;
case MEDIA_BUS_FMT_YUV16_1X48:
- input_fmts[i++] = MEDIA_BUS_FMT_YUV16_1X48;
- input_fmts[i++] = MEDIA_BUS_FMT_RGB161616_1X48;
+ if (hdmi->csc_available)
+ input_fmts[i++] = MEDIA_BUS_FMT_YUV16_1X48;
break;
/*YUV 4:2:0 */
@@ -2765,15 +2791,24 @@ static int dw_hdmi_bridge_atomic_check(struct drm_bridge *bridge,
{
struct dw_hdmi *hdmi = bridge->driver_private;
- hdmi->hdmi_data.enc_out_bus_format =
- bridge_state->output_bus_cfg.format;
+ if (!hdmi->csc_available &&
+ bridge_state->output_bus_cfg.format != bridge_state->input_bus_cfg.format) {
+ dev_warn(hdmi->dev, "different input format 0x%04x & output format 0x%04x while CSC isn't usable, fallback to safe format\n",
+ bridge_state->input_bus_cfg.format,
+ bridge_state->output_bus_cfg.format);
+ hdmi->hdmi_data.enc_out_bus_format = MEDIA_BUS_FMT_FIXED;
+ hdmi->hdmi_data.enc_in_bus_format = MEDIA_BUS_FMT_FIXED;
+ } else {
+ hdmi->hdmi_data.enc_out_bus_format =
+ bridge_state->output_bus_cfg.format;
- hdmi->hdmi_data.enc_in_bus_format =
- bridge_state->input_bus_cfg.format;
+ hdmi->hdmi_data.enc_in_bus_format =
+ bridge_state->input_bus_cfg.format;
- dev_dbg(hdmi->dev, "input format 0x%04x, output format 0x%04x\n",
- bridge_state->input_bus_cfg.format,
- bridge_state->output_bus_cfg.format);
+ dev_dbg(hdmi->dev, "input format 0x%04x, output format 0x%04x\n",
+ bridge_state->input_bus_cfg.format,
+ bridge_state->output_bus_cfg.format);
+ }
return 0;
}
@@ -3479,6 +3514,9 @@ struct dw_hdmi *dw_hdmi_probe(struct platform_device *pdev,
hdmi->cec = platform_device_register_full(&pdevinfo);
}
+ /* Get CSC useability from config0 register and permit override for platforms */
+ hdmi->csc_available = !plat_data->disable_csc || (config0 & HDMI_CONFIG0_CSC);
+
drm_bridge_add(&hdmi->bridge);
return hdmi;
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.h b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.h
index 1999db05bc3b..279722e4d189 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.h
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.h
@@ -541,6 +541,7 @@ enum {
/* CONFIG0_ID field values */
HDMI_CONFIG0_I2S = 0x10,
+ HDMI_CONFIG0_CSC = 0x04,
HDMI_CONFIG0_CEC = 0x02,
/* CONFIG1_ID field values */
diff --git a/include/drm/bridge/dw_hdmi.h b/include/drm/bridge/dw_hdmi.h
index 2a1f85f9a8a3..b2f689cbe864 100644
--- a/include/drm/bridge/dw_hdmi.h
+++ b/include/drm/bridge/dw_hdmi.h
@@ -157,6 +157,7 @@ struct dw_hdmi_plat_data {
unsigned long mpixelclock);
unsigned int disable_cec : 1;
+ unsigned int disable_csc : 1;
};
struct dw_hdmi *dw_hdmi_probe(struct platform_device *pdev,
=================><==============================================================
Neil
>
> BR and thanks,
> Nikolaus
>
> [1]: https://lore.kernel.org/all/24a27226a22adf5f5573f013e5d7d89b0ec73664.1645895582.git.hns@goldelico.com/
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