> -----Original Message-----
> From: Intel-gfx <intel-gfx-bounces@xxxxxxxxxxxxxxxxxxxxx> On Behalf Of Nemesa
> Garg
> Sent: Friday, October 27, 2023 3:24 PM
> To: intel-gfx@xxxxxxxxxxxxxxxxxxxxx
> Subject: [v2 1/2] drm/i915/display: Add support for darskscreen
> detection
>
> Darkscreen detection checks if all the pixels of the frame are less then or equal
> to the comparision value. The comparision value is set to 256 i.e black. So upon
> getting black pixels from the pipe, the dark screen detect bit is set and an error
> message will be printed.
>
> v2: Addressed review comments (Jani)
>
> Signed-off-by: Nemesa Garg <nemesa.garg@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/Makefile | 1 +
> .../gpu/drm/i915/display/intel_darkscreen.c | 87 +++++++++++++++++++
> .../gpu/drm/i915/display/intel_darkscreen.h | 26 ++++++
> .../drm/i915/display/intel_display_types.h | 2 +
> drivers/gpu/drm/i915/i915_reg.h | 8 ++
> 5 files changed, 124 insertions(+)
> create mode 100644 drivers/gpu/drm/i915/display/intel_darkscreen.c
> create mode 100644 drivers/gpu/drm/i915/display/intel_darkscreen.h
>
> diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
> index 88b2bb005014..538d5a42f9e3 100644
> --- a/drivers/gpu/drm/i915/Makefile
> +++ b/drivers/gpu/drm/i915/Makefile
> @@ -254,6 +254,7 @@ i915-y += \
> display/intel_crtc.o \
> display/intel_crtc_state_dump.o \
> display/intel_cursor.o \
> + display/intel_darkscreen.o \
> display/intel_display.o \
> display/intel_display_driver.o \
> display/intel_display_irq.o \
> diff --git a/drivers/gpu/drm/i915/display/intel_darkscreen.c
> b/drivers/gpu/drm/i915/display/intel_darkscreen.c
> new file mode 100644
> index 000000000000..0be719c76c4e
> --- /dev/null
> +++ b/drivers/gpu/drm/i915/display/intel_darkscreen.c
> @@ -0,0 +1,87 @@
> +// SPDX-License-Identifier: MIT
> +/*
> + * Copyright © 2023 Intel Corporation
> + *
> + */
> +
> +#include "i915_reg.h"
> +#include "intel_de.h"
> +#include "intel_display_types.h"
> +
> +#define COLOR_DEPTH_6BPC 6
> +#define COLOR_DEPTH_8BPC 8
> +#define COLOR_DEPTH_10BPC 10
> +#define COLOR_DEPTH_12BPC 12
> +
> +#define COMPARE_VALUE_6_BPC 4
> +#define COMPARE_VALUE_8_BPC 16
> +#define COMPARE_VALUE_10_BPC 64
> +#define COMPARE_VALUE_12_BPC 256
> +
> +#define COMPARE_VALUE_CALCULATION_FACTOR 12
> +
> +/*
> + * Checks the color format and compute the comapre value based on bpc.
> + */
Can we have this in proper kernel doc format?
> +void intel_dark_screen_enable(struct intel_crtc_state *crtc_state) {
> + enum transcoder cpu_transcoder = crtc_state->cpu_transcoder;
> + struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
> + struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
> + u32 comparevalue;
> +
> + if (!crtc->dark_screen.enable)
> + return;
> +
> + if (crtc_state->output_format != INTEL_OUTPUT_FORMAT_RGB)
> + return;
Better to have an error print saying not supported.
Thanks and Regards,
Arun R Murthy
-------------------
> +
> + switch (crtc_state->pipe_bpp / 3) {
> + case COLOR_DEPTH_6BPC:
> + comparevalue = COMPARE_VALUE_6_BPC;
> + break;
> + case COLOR_DEPTH_8BPC:
> + comparevalue = COMPARE_VALUE_8_BPC;
> + break;
> + case COLOR_DEPTH_10BPC:
> + comparevalue = COMPARE_VALUE_10_BPC;
> + break;
> + case COLOR_DEPTH_12BPC:
> + comparevalue = COMPARE_VALUE_12_BPC;
> + break;
> + default:
> + drm_dbg(&dev_priv->drm,
> + "Bpc value is incorrect:%d\n",
> + crtc_state->pipe_bpp / 3);
> + return;
> + }
> +
> + comparevalue = comparevalue <<
> + (COMPARE_VALUE_CALCULATION_FACTOR - crtc_state-
> >pipe_bpp / 3);
> +
> + intel_de_write(dev_priv, DARK_SCREEN(cpu_transcoder),
> + DARK_SCREEN_ENABLE | DARK_SCREEN_DETECT |
> + DARK_SCREEN_DONE |
> DARK_SCREEN_COMPARE_VAL(comparevalue));
> +
> + intel_de_wait_for_set(dev_priv,
> + DARK_SCREEN(crtc->config->cpu_transcoder),
> DARK_SCREEN_DONE,
> +1);
> +
> + if (intel_de_read(dev_priv, DARK_SCREEN(crtc->config-
> >cpu_transcoder)) &
> + DARK_SCREEN_DETECT) {
> + drm_err(&dev_priv->drm,
> + "Dark Screen detected:%c\n",
> + pipe_name(crtc->pipe));
> + }
> +
> + intel_de_rmw(dev_priv, DARK_SCREEN(crtc->config->cpu_transcoder),
> 1, DARK_SCREEN_DETECT |
> + DARK_SCREEN_DONE);
> +}
> +
> +void intel_dark_screen_disable(struct intel_crtc_state *crtc_state) {
> + enum transcoder cpu_transcoder = crtc_state->cpu_transcoder;
> + struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
> + struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
> +
> + intel_de_write(dev_priv, DARK_SCREEN(cpu_transcoder), 0); }
> diff --git a/drivers/gpu/drm/i915/display/intel_darkscreen.h
> b/drivers/gpu/drm/i915/display/intel_darkscreen.h
> new file mode 100644
> index 000000000000..366e43499fc4
> --- /dev/null
> +++ b/drivers/gpu/drm/i915/display/intel_darkscreen.h
> @@ -0,0 +1,26 @@
> +/* SPDX-License-Identifier: MIT */
> +/*
> + * Copyright © 2023 Intel Corporation
> + *
> + */
> +
> +#ifndef __INTEL_DARKSCREEN_H__
> +#define __INTEL_DARKSCREEN_H__
> +
> +#include <linux/types.h>
> +
> +struct intel_crtc_state;
> +struct intel_crtc;
> +
> +struct intel_darkscreen {
> + bool enable;
> +};
> +
> +#ifdef CONFIG_DEBUG_FS
> +void intel_dark_screen_enable(struct intel_crtc_state *crtc_state);
> +void intel_dark_screen_disable(struct intel_crtc_state *crtc_state);
> +void intel_darkscreen_crtc_debugfs_add(struct intel_crtc *crtc);
> +
> +#endif
> +
> +#endif /* __INTEL_DARKSCREEN_H_ */
> diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h
> b/drivers/gpu/drm/i915/display/intel_display_types.h
> index 65ea37fe8cff..bd0306e9318f 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> @@ -49,6 +49,7 @@
> #include "i915_vma.h"
> #include "i915_vma_types.h"
> #include "intel_bios.h"
> +#include "intel_darkscreen.h"
> #include "intel_display.h"
> #include "intel_display_limits.h"
> #include "intel_display_power.h"
> @@ -1517,6 +1518,7 @@ struct intel_crtc {
>
> #ifdef CONFIG_DEBUG_FS
> struct intel_pipe_crc pipe_crc;
> + struct intel_darkscreen dark_screen;
> #endif
> };
>
> diff --git a/drivers/gpu/drm/i915/i915_reg.h
> b/drivers/gpu/drm/i915/i915_reg.h index 135e8d8dbdf0..a9f7b80a56cf
> 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -2097,6 +2097,14 @@
> #define TRANS_PUSH_EN REG_BIT(31)
> #define TRANS_PUSH_SEND REG_BIT(30)
>
> +#define _DARK_SCREEN_PIPE_A 0x60120
> +#define DARK_SCREEN(trans) _MMIO_TRANS2(trans,
> _DARK_SCREEN_PIPE_A)
> +#define DARK_SCREEN_ENABLE REG_BIT(31)
> +#define DARK_SCREEN_DETECT REG_BIT(29)
> +#define DARK_SCREEN_DONE REG_BIT(28)
> +#define DARK_SCREEN_COMPARE_MASK REG_GENMASK(9, 0)
> +#define DARK_SCREEN_COMPARE_VAL(x)
> REG_FIELD_PREP(DARK_SCREEN_COMPARE_MASK, (x))
> +
> /* VGA port control */
> #define ADPA _MMIO(0x61100)
> #define PCH_ADPA _MMIO(0xe1100)
> --
> 2.25.1
