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From:   Alex Deucher <alexdeucher@gmail.com>
Date:   Fri, 25 Mar 2022 09:06:57 -0400
Message-ID: <CADnq5_MGrkDxGBfpg9XfJ-e=fSr9dx22VJTKz6BLQemTq7Ck8Q@mail.gmail.com>
Subject: Re: [PATCH v2 3/25] drm/amdgpu: Disable ABM when AC mode
To:     Ryan Lin <tsung-hua.lin@amd.com>
Cc:     "Wentland, Harry" <harry.wentland@amd.com>,
        "Leo (Sunpeng) Li" <sunpeng.li@amd.com>,
        "Deucher, Alexander" <alexander.deucher@amd.com>,
        Christian Koenig <christian.koenig@amd.com>,
        Chunming Zhou <David1.Zhou@amd.com>,
        Dave Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        Sean Paul <seanpaul@chromium.org>,
        Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>,
        "Kazlauskas, Nicholas" <nicholas.kazlauskas@amd.com>,
        Sasha Levin <sashal@kernel.org>,
        Mark Yacoub <markyacoub@google.com>,
        Victor Lu <victorchengchi.lu@amd.com>,
        ching-shih.li@amd.corp-partner.google.com,
        "Siqueira, Rodrigo" <Rodrigo.Siqueira@amd.com>,
        ddavenport@chromium.org,
        amd-gfx list <amd-gfx@lists.freedesktop.org>,
        Maling list - DRI developers 
        <dri-devel@lists.freedesktop.org>,
        LKML <linux-kernel@vger.kernel.org>, leon.li@amd.com
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On Fri, Mar 25, 2022 at 2:27 AM Ryan Lin <tsung-hua.lin@amd.com> wrote:
>
> Disable ABM feature when the system is running on AC mode to get
> the more perfect contrast of the display.
>
> 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;
> +       }
> +

We already set adev->pm.ac_power in amdgpu_pm_acpi_event_handler()
which gets called a few lines below.

Alex


>         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) {
> +               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;
>
> --
> 2.25.1
>