[AMD Official Use Only] Hi Christian, There is already a string comparison in the same function. I just reference that to port this solution. #define ACPI_AC_CLASS "ac_adapter" static int amdgpu_acpi_event(struct notifier_block *nb, unsigned long val, void *data) { 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) { <-------------------here! if (power_supply_is_system_supplied() > 0) DRM_DEBUG_DRIVER("pm: AC\n"); else DRM_DEBUG_DRIVER("pm: DC\n"); amdgpu_pm_acpi_event_handler(adev); } /* Check for pending SBIOS requests */ return amdgpu_atif_handler(adev, entry); } Thanks, Ryan Lin. -----Original Message----- From: Koenig, Christian <Christian.Koenig@xxxxxxx> Sent: Friday, March 25, 2022 2:58 PM To: Lin, Tsung-hua (Ryan) <Tsung-hua.Lin@xxxxxxx>; Wentland, Harry <Harry.Wentland@xxxxxxx>; Li, Sun peng (Leo) <Sunpeng.Li@xxxxxxx>; Deucher, Alexander <Alexander.Deucher@xxxxxxx>; David1.Zhou@xxxxxxx; airlied@xxxxxxxx; daniel@xxxxxxxx; seanpaul@xxxxxxxxxxxx; bas@xxxxxxxxxxxxxxxxxxx; Kazlauskas, Nicholas <Nicholas.Kazlauskas@xxxxxxx>; sashal@xxxxxxxxxx; markyacoub@xxxxxxxxxx; victorchengchi.lu@xxxxxxx; ching-shih.li@xxxxxxxxxxxxxxxxxxxxxxxxxxx; Siqueira, Rodrigo <Rodrigo.Siqueira@xxxxxxx>; ddavenport@xxxxxxxxxxxx; amd-gfx@xxxxxxxxxxxxxxxxxxxxx; dri-devel@xxxxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Li, Leon <Leon.Li@xxxxxxx> Subject: Re: [PATCH v2 3/25] drm/amdgpu: Disable ABM when AC mode Am 25.03.22 um 05:05 schrieb Ryan Lin: > 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@xxxxxxx> > > --- > 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) { String comparison in a hot path is not something we usually like to see in the kernel. Isn't there any other way to detect that? Like a flag or similar? Regards, Christian. > + 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) { > + 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; >