drm/lima: add governor data with pre-defined thresholds

This patch adapts the panfrost pre-defined thresholds change [0] to the
lima driver to improve real-world performance. The upthreshold value has
been set to ramp GPU frequency to max freq faster (compared to panfrost)
to compensate for the lower overall performance of utgard devices.

[0] https://patchwork.kernel.org/project/dri-devel/patch/20210121170445.19761-1-lukasz.luba@arm.com/

Signed-off-by: Christian Hewitt <christianshewitt@gmail.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Qiang Yu <yuq825@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210127194047.21462-1-christianshewitt@gmail.com

diff --git a/drivers/gpu/drm/lima/lima_devfreq.c b/drivers/gpu/drm/lima/lima_devfreq.c
index f1c9eb3..4f64940 100644 (file)
--- a/drivers/gpu/drm/lima/lima_devfreq.c
+++ b/drivers/gpu/drm/lima/lima_devfreq.c
@@ -164,8 +164,16 @@ int lima_devfreq_init(struct lima_device *ldev)
        lima_devfreq_profile.initial_freq = cur_freq;
        dev_pm_opp_put(opp);
 
+       /*
+        * Setup default thresholds for the simple_ondemand governor.
+        * The values are chosen based on experiments.
+        */
+       ldevfreq->gov_data.upthreshold = 30;
+       ldevfreq->gov_data.downdifferential = 5;
+
        devfreq = devm_devfreq_add_device(dev, &lima_devfreq_profile,
-                                         DEVFREQ_GOV_SIMPLE_ONDEMAND, NULL);
+                                         DEVFREQ_GOV_SIMPLE_ONDEMAND,
+                                         &ldevfreq->gov_data);
        if (IS_ERR(devfreq)) {
                dev_err(dev, "Couldn't initialize GPU devfreq\n");
                ret = PTR_ERR(devfreq);

diff --git a/drivers/gpu/drm/lima/lima_devfreq.h b/drivers/gpu/drm/lima/lima_devfreq.h
index 2d9b300..b0c7c73 100644 (file)
--- a/drivers/gpu/drm/lima/lima_devfreq.h
+++ b/drivers/gpu/drm/lima/lima_devfreq.h
@@ -4,6 +4,7 @@
 #ifndef __LIMA_DEVFREQ_H__
 #define __LIMA_DEVFREQ_H__
 
+#include <linux/devfreq.h>
 #include <linux/spinlock.h>
 #include <linux/ktime.h>
 
@@ -18,6 +19,7 @@ struct lima_devfreq {
        struct opp_table *clkname_opp_table;
        struct opp_table *regulators_opp_table;
        struct thermal_cooling_device *cooling;
+       struct devfreq_simple_ondemand_data gov_data;
 
        ktime_t busy_time;
        ktime_t idle_time;