drm/amd/display: Move backlight pwm enable function call

[Why]
Can't call dmub_abm_enable_fractional_pwm from dmub_abm_create as
dmub_srv is still null at this init stage, and therefore can't call to
fw.

[How]
Move call to dmub_abm_init_backlight. This should be the first call from
the driver for ABM.
Signed-off-by: Wyatt Wood <wyatt.wood@amd.com>
Reviewed-by: Nicholas Kazlauskas <Nicholas.Kazlauskas@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dce/dmub_abm.c

@@ -257,11 +257,28 @@ static bool dmub_abm_immediate_disable(struct abm *abm)
 	return true;
 }
 
+static void dmub_abm_enable_fractional_pwm(struct dc_context *dc)
+{
+	union dmub_rb_cmd cmd;
+	uint32_t fractional_pwm = (dc->dc->config.disable_fractional_pwm == false) ? 1 : 0;
+
+	cmd.abm_set_pwm_frac.header.type = DMUB_CMD__ABM;
+	cmd.abm_set_pwm_frac.header.sub_type = DMUB_CMD__ABM_SET_PWM_FRAC;
+	cmd.abm_set_pwm_frac.abm_set_pwm_frac_data.fractional_pwm = fractional_pwm;
+	cmd.abm_set_pwm_frac.header.payload_bytes = sizeof(struct dmub_cmd_abm_set_pwm_frac_data);
+
+	dc_dmub_srv_cmd_queue(dc->dmub_srv, &cmd.abm_set_pwm_frac.header);
+	dc_dmub_srv_cmd_execute(dc->dmub_srv);
+	dc_dmub_srv_wait_idle(dc->dmub_srv);
+}
+
 static bool dmub_abm_init_backlight(struct abm *abm)
 {
 	struct dce_abm *dce_abm = TO_DMUB_ABM(abm);
 	uint32_t value;
 
+	dmub_abm_enable_fractional_pwm(abm->ctx);
+
 	/* It must not be 0, so we have to restore them
 	 * Bios bug w/a - period resets to zero,
 	 * restoring to cache values which is always correct
@@ -331,21 +348,6 @@ static bool dmub_abm_set_backlight_level_pwm(
 	return true;
 }
 
-static void dmub_abm_enable_fractional_pwm(struct dc_context *dc)
-{
-	union dmub_rb_cmd cmd;
-	uint32_t fractional_pwm = (dc->dc->config.disable_fractional_pwm == false) ? 1 : 0;
-
-	cmd.abm_set_pwm_frac.header.type = DMUB_CMD__ABM;
-	cmd.abm_set_pwm_frac.header.sub_type = DMUB_CMD__ABM_SET_PWM_FRAC;
-	cmd.abm_set_pwm_frac.abm_set_pwm_frac_data.fractional_pwm = fractional_pwm;
-	cmd.abm_set_pwm_frac.header.payload_bytes = sizeof(struct dmub_cmd_abm_set_pwm_frac_data);
-
-	dc_dmub_srv_cmd_queue(dc->dmub_srv, &cmd.abm_set_pwm_frac.header);
-	dc_dmub_srv_cmd_execute(dc->dmub_srv);
-	dc_dmub_srv_wait_idle(dc->dmub_srv);
-}
-
 static bool dmub_abm_load_config(struct abm *abm,
 	unsigned int start_offset,
 	const char *src,
@@ -386,8 +388,6 @@ static void dmub_abm_construct(
 	abm_dce->regs = regs;
 	abm_dce->abm_shift = abm_shift;
 	abm_dce->abm_mask = abm_mask;
-
-	dmub_abm_enable_fractional_pwm(ctx);
 }
 
 struct abm *dmub_abm_create(