Re: [PATCH v2 3/25] drm/amdgpu: Disable ABM when AC mode

[Harry Wentland <harry.wentland@amd.com>]

On 2022-03-25 00:05, Ryan Lin wrote:
> Disable ABM feature when the system is running on AC mode to get
> the more perfect contrast of the display.

It says patch 3 out of 25. Are there other patches? If so, I can't
find them in my mailbox and neither can patchwork
https://patchwork.freedesktop.org/series/101767/
 
> Signed-off-by: Ryan Lin <tsung-hua.lin@amd.com>
> 
> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c      |  4 ++
>  drivers/gpu/drm/amd/amdgpu/amdgpu_device.c    |  1 +
>  drivers/gpu/drm/amd/display/dc/dce/dmub_abm.c | 58 ++++++++++++-------
>  drivers/gpu/drm/amd/pm/inc/amdgpu_dpm.h       |  1 +
>  4 files changed, 42 insertions(+), 22 deletions(-)
> 
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c
> index c560c1ab62ecb..bc8bb9aad2e36 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c
> @@ -822,6 +822,10 @@ static int amdgpu_acpi_event(struct notifier_block *nb,
>  	struct amdgpu_device *adev = container_of(nb, struct amdgpu_device, acpi_nb);
>  	struct acpi_bus_event *entry = (struct acpi_bus_event *)data;
>  
> +	if (strcmp(entry->device_class, "battery") == 0) {
> +		adev->pm.ac_power = power_supply_is_system_supplied() > 0;
> +	}
> +
>  	if (strcmp(entry->device_class, ACPI_AC_CLASS) == 0) {
>  		if (power_supply_is_system_supplied() > 0)
>  			DRM_DEBUG_DRIVER("pm: AC\n");
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> index abfcc1304ba0c..3a0afe7602727 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> @@ -3454,6 +3454,7 @@ int amdgpu_device_init(struct amdgpu_device *adev,
>  
>  	adev->gfx.gfx_off_req_count = 1;
>  	adev->pm.ac_power = power_supply_is_system_supplied() > 0;
> +	adev->pm.old_ac_power = true;
>  
>  	atomic_set(&adev->throttling_logging_enabled, 1);
>  	/*
> diff --git a/drivers/gpu/drm/amd/display/dc/dce/dmub_abm.c b/drivers/gpu/drm/amd/display/dc/dce/dmub_abm.c
> index 54a1408c8015c..478a734b66926 100644
> --- a/drivers/gpu/drm/amd/display/dc/dce/dmub_abm.c
> +++ b/drivers/gpu/drm/amd/display/dc/dce/dmub_abm.c
> @@ -23,6 +23,8 @@
>   *
>   */
>  
> +#include <linux/power_supply.h>
> +#include "amdgpu.h"
>  #include "dmub_abm.h"
>  #include "dce_abm.h"
>  #include "dc.h"
> @@ -51,6 +53,7 @@
>  #define DISABLE_ABM_IMMEDIATELY 255
>  
>  
> +extern uint amdgpu_dm_abm_level;
>  
>  static void dmub_abm_enable_fractional_pwm(struct dc_context *dc)
>  {
> @@ -117,28 +120,6 @@ static void dmub_abm_init(struct abm *abm, uint32_t backlight)
>  	dmub_abm_enable_fractional_pwm(abm->ctx);
>  }
>  
> -static unsigned int dmub_abm_get_current_backlight(struct abm *abm)
> -{
> -	struct dce_abm *dce_abm = TO_DMUB_ABM(abm);
> -	unsigned int backlight = REG_READ(BL1_PWM_CURRENT_ABM_LEVEL);
> -
> -	/* return backlight in hardware format which is unsigned 17 bits, with
> -	 * 1 bit integer and 16 bit fractional
> -	 */
> -	return backlight;
> -}
> -
> -static unsigned int dmub_abm_get_target_backlight(struct abm *abm)
> -{
> -	struct dce_abm *dce_abm = TO_DMUB_ABM(abm);
> -	unsigned int backlight = REG_READ(BL1_PWM_TARGET_ABM_LEVEL);
> -
> -	/* return backlight in hardware format which is unsigned 17 bits, with
> -	 * 1 bit integer and 16 bit fractional
> -	 */
> -	return backlight;
> -}
> -
>  static bool dmub_abm_set_level(struct abm *abm, uint32_t level)
>  {
>  	union dmub_rb_cmd cmd;
> @@ -148,6 +129,9 @@ static bool dmub_abm_set_level(struct abm *abm, uint32_t level)
>  	int edp_num;
>  	uint8_t panel_mask = 0;
>  
> +	if (power_supply_is_system_supplied() > 0)
> +		level = 0;
> +
>  	get_edp_links(dc->dc, edp_links, &edp_num);
>  
>  	for (i = 0; i < edp_num; i++) {
> @@ -170,6 +154,36 @@ static bool dmub_abm_set_level(struct abm *abm, uint32_t level)
>  	return true;
>  }
>  
> +static unsigned int dmub_abm_get_current_backlight(struct abm *abm)
> +{
> +	struct dce_abm *dce_abm = TO_DMUB_ABM(abm);
> +	unsigned int backlight = REG_READ(BL1_PWM_CURRENT_ABM_LEVEL);
> +	struct dc_context *dc = abm->ctx;
> +	struct amdgpu_device *adev = dc->driver_context;
> +
> +	if (adev->pm.ac_power != adev->pm.old_ac_power) {

This file lives in DC, which is shared code between Windows and Linux. We
cannot directly use adev here. Any information needs to go through DC structs.

I seem to remember someone saying that ABM gets disabled on Windows when
we're in AC mode. Have you checked with our Windows guys about this? I feel
we're re-inventing the wheel here for no good reason.

Harry

> +		dmub_abm_set_level(abm, amdgpu_dm_abm_level);
> +		adev->pm.ac_power = power_supply_is_system_supplied() > 0;
> +		adev->pm.old_ac_power = adev->pm.ac_power;
> +	}
> +
> +	/* return backlight in hardware format which is unsigned 17 bits, with
> +	 * 1 bit integer and 16 bit fractional
> +	 */
> +	return backlight;
> +}
> +
> +static unsigned int dmub_abm_get_target_backlight(struct abm *abm)
> +{
> +	struct dce_abm *dce_abm = TO_DMUB_ABM(abm);
> +	unsigned int backlight = REG_READ(BL1_PWM_TARGET_ABM_LEVEL);
> +
> +	/* return backlight in hardware format which is unsigned 17 bits, with
> +	 * 1 bit integer and 16 bit fractional
> +	 */
> +	return backlight;
> +}
> +
>  static bool dmub_abm_init_config(struct abm *abm,
>  	const char *src,
>  	unsigned int bytes,
> diff --git a/drivers/gpu/drm/amd/pm/inc/amdgpu_dpm.h b/drivers/gpu/drm/amd/pm/inc/amdgpu_dpm.h
> index f6e0e7d8a0077..de459411a0e83 100644
> --- a/drivers/gpu/drm/amd/pm/inc/amdgpu_dpm.h
> +++ b/drivers/gpu/drm/amd/pm/inc/amdgpu_dpm.h
> @@ -445,6 +445,7 @@ struct amdgpu_pm {
>  	uint32_t                smu_prv_buffer_size;
>  	struct amdgpu_bo        *smu_prv_buffer;
>  	bool ac_power;
> +	bool old_ac_power;
>  	/* powerplay feature */
>  	uint32_t pp_feature;
>