On Fri, Mar 25, 2022 at 08:22:29AM +0100, Christian König wrote:
> Hi Ryan,
>
> we should try to avoid that and if it isn't possible at least use some
> constant like ACPI_AC_CLASS.
>
> Could be that the information isn't available otherwise. Alex should know
> more about that.
I wonder whether we shouldn't need a more dedicated notification from acpi
for power supply events instead of stitching this together ourselves. At
least this kind of stuff feels more into the policy/tuning territory where
a bit more careful interfaces might be good instead of just "hey there's
this very funny acpi protocol we just have to take part in to not upset
the hw/fw".
-Daniel
>
> Regards,
> Christian.
>
> Am 25.03.22 um 08:09 schrieb Lin, Tsung-hua (Ryan):
> > [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;
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
