Re: [PATCH v2 2/8] drm/panfrost: Rework runtime PM initialization

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 23/08/2019 03:12, Rob Herring wrote:
There's a few issues with the runtime PM initialization.

The documentation states pm_runtime_set_active() should be called before
pm_runtime_enable(). The pm_runtime_put_autosuspend() could suspend the GPU
before panfrost_perfcnt_init() is called which touches the h/w. The
autosuspend delay keeps things from breaking. There's no need explicitly
power off the GPU only to wake back up with pm_runtime_get_sync(). Just
delaying pm_runtime_enable to the end of probe is sufficient.

Lets move all the runtime PM calls into the probe() function so they are
all in one place and are done after all initialization.

Cc: Tomeu Vizoso <tomeu.vizoso@xxxxxxxxxxxxx>
Cc: Steven Price <steven.price@xxxxxxx>
Cc: Alyssa Rosenzweig <alyssa.rosenzweig@xxxxxxxxxxxxx>
Cc: David Airlie <airlied@xxxxxxxx>
Cc: Daniel Vetter <daniel@xxxxxxxx>
Signed-off-by: Rob Herring <robh@xxxxxxxxxx>
---
v2: new patch

  drivers/gpu/drm/panfrost/panfrost_device.c |  9 ---------
  drivers/gpu/drm/panfrost/panfrost_drv.c    | 10 ++++++----
  2 files changed, 6 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/panfrost/panfrost_device.c b/drivers/gpu/drm/panfrost/panfrost_device.c
index 4da71bb56c20..73805210834e 100644
--- a/drivers/gpu/drm/panfrost/panfrost_device.c
+++ b/drivers/gpu/drm/panfrost/panfrost_device.c
@@ -5,7 +5,6 @@
  #include <linux/clk.h>
  #include <linux/reset.h>
  #include <linux/platform_device.h>
-#include <linux/pm_runtime.h>
  #include <linux/regulator/consumer.h>
#include "panfrost_device.h"
@@ -166,14 +165,6 @@ int panfrost_device_init(struct panfrost_device *pfdev)
  	if (err)
  		goto err_out4;
- /* runtime PM will wake us up later */
-	panfrost_gpu_power_off(pfdev);
-
-	pm_runtime_set_active(pfdev->dev);
-	pm_runtime_get_sync(pfdev->dev);
-	pm_runtime_mark_last_busy(pfdev->dev);
-	pm_runtime_put_autosuspend(pfdev->dev);
-
  	err = panfrost_perfcnt_init(pfdev);
  	if (err)
  		goto err_out5;
diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c b/drivers/gpu/drm/panfrost/panfrost_drv.c
index d74442d71048..f27e3d6aec12 100644
--- a/drivers/gpu/drm/panfrost/panfrost_drv.c
+++ b/drivers/gpu/drm/panfrost/panfrost_drv.c
@@ -523,10 +523,6 @@ static int panfrost_probe(struct platform_device *pdev)
  	mutex_init(&pfdev->shrinker_lock);
  	INIT_LIST_HEAD(&pfdev->shrinker_list);
- pm_runtime_use_autosuspend(pfdev->dev);
-	pm_runtime_set_autosuspend_delay(pfdev->dev, 50); /* ~3 frames */
-	pm_runtime_enable(pfdev->dev);
-
  	err = panfrost_device_init(pfdev);
  	if (err) {
  		if (err != -EPROBE_DEFER)
@@ -541,6 +537,12 @@ static int panfrost_probe(struct platform_device *pdev)
  		goto err_out1;
  	}
+ pm_runtime_set_active(pfdev->dev);
+	pm_runtime_use_autosuspend(pfdev->dev);
+	pm_runtime_set_autosuspend_delay(pfdev->dev, 0); /* ~3 frames */

Hmm... different timeout, same comment - something seems amiss there, unless perhaps it's all within rounding error anyway?

Other than that, the overall change looks sensible to me.

Robin.

+	pm_runtime_mark_last_busy(pfdev->dev);
+	pm_runtime_enable(pfdev->dev);
+
  	/*
  	 * Register the DRM device with the core and the connectors with
  	 * sysfs

_______________________________________________
dri-devel mailing list
dri-devel@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/dri-devel




[Index of Archives]     [Linux DRI Users]     [Linux Intel Graphics]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [XFree86]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [XFree86]
  Powered by Linux