[PATCH v8 08/16] drm/panfrost: Move all DRM device initialisation into device_init()

From: Adrián Larumbe

Date: Mon Sep 07 2026 - 16:20:50 EST


Ideally the probe() function will do as little as possible, and all device
initialisation and registration should happen inside the panfrost device
subsystem, just like it's done in Panthor. This also simplifies resource
unwinding in the error path.

Do the same thing for DRM driver remove, as in, sweep most of the action
into panfrost_device_fini(), just like we did for device probe.

Signed-off-by: Adrián Larumbe <adrian.larumbe@xxxxxxxxxxxxx>
---
drivers/gpu/drm/panfrost/panfrost_device.c | 37 +++++++++++++++++++++++
drivers/gpu/drm/panfrost/panfrost_drv.c | 47 +-----------------------------
2 files changed, 38 insertions(+), 46 deletions(-)

diff --git a/drivers/gpu/drm/panfrost/panfrost_device.c b/drivers/gpu/drm/panfrost/panfrost_device.c
index 48135e412b6c..be4443e41d9a 100644
--- a/drivers/gpu/drm/panfrost/panfrost_device.c
+++ b/drivers/gpu/drm/panfrost/panfrost_device.c
@@ -8,6 +8,7 @@
#include <linux/pm_domain.h>
#include <linux/pm_runtime.h>
#include <linux/regulator/consumer.h>
+#include <drm/drm_drv.h>

#include "panfrost_device.h"
#include "panfrost_devfreq.h"
@@ -227,6 +228,12 @@ int panfrost_device_init(struct panfrost_device *pfdev)
{
int err;

+ pfdev->comp = of_device_get_match_data(pfdev->base.dev);
+ if (!pfdev->comp)
+ return -ENODEV;
+
+ pfdev->coherent = device_get_dma_attr(pfdev->base.dev) == DEV_DMA_COHERENT;
+
#ifdef CONFIG_DEBUG_FS
mutex_init(&pfdev->debugfs.gems_lock);
INIT_LIST_HEAD(&pfdev->debugfs.gems_list);
@@ -288,8 +295,31 @@ int panfrost_device_init(struct panfrost_device *pfdev)
if (err)
goto out_perfcnt;

+ pm_runtime_set_active(pfdev->base.dev);
+ pm_runtime_mark_last_busy(pfdev->base.dev);
+ pm_runtime_get_noresume(pfdev->base.dev);
+ pm_runtime_enable(pfdev->base.dev);
+ pm_runtime_set_autosuspend_delay(pfdev->base.dev, 50); /* ~3 frames */
+ pm_runtime_use_autosuspend(pfdev->base.dev);
+
+ /*
+ * Register the DRM device with the core and the connectors with
+ * sysfs
+ */
+ err = drm_dev_register(&pfdev->base, 0);
+ if (err < 0)
+ goto err_disable_rpm;
+
+ pm_runtime_put_autosuspend(pfdev->base.dev);
+
return 0;

+err_disable_rpm:
+ pm_runtime_dont_use_autosuspend(pfdev->base.dev);
+ pm_runtime_disable(pfdev->base.dev);
+ pm_runtime_put_noidle(pfdev->base.dev);
+ pm_runtime_set_suspended(pfdev->base.dev);
+ panfrost_gem_fini(pfdev);
out_perfcnt:
panfrost_perfcnt_fini(pfdev);
out_job:
@@ -313,6 +343,13 @@ int panfrost_device_init(struct panfrost_device *pfdev)

void panfrost_device_fini(struct panfrost_device *pfdev)
{
+ pm_runtime_get_sync(pfdev->base.dev);
+
+ pm_runtime_dont_use_autosuspend(pfdev->base.dev);
+ pm_runtime_disable(pfdev->base.dev);
+ pm_runtime_put_noidle(pfdev->base.dev);
+ pm_runtime_set_suspended(pfdev->base.dev);
+
panfrost_gem_fini(pfdev);
panfrost_perfcnt_fini(pfdev);
panfrost_jm_fini(pfdev);
diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c b/drivers/gpu/drm/panfrost/panfrost_drv.c
index a3eff77add55..f77780c72a1a 100644
--- a/drivers/gpu/drm/panfrost/panfrost_drv.c
+++ b/drivers/gpu/drm/panfrost/panfrost_drv.c
@@ -830,7 +830,6 @@ static const struct drm_driver panfrost_drm_driver = {
static int panfrost_probe(struct platform_device *pdev)
{
struct panfrost_device *pfdev;
- int err;

pfdev = devm_drm_dev_alloc(&pdev->dev, &panfrost_drm_driver,
struct panfrost_device, base);
@@ -839,46 +838,7 @@ static int panfrost_probe(struct platform_device *pdev)

platform_set_drvdata(pdev, pfdev);

- pfdev->comp = of_device_get_match_data(&pdev->dev);
- if (!pfdev->comp)
- return -ENODEV;
-
- pfdev->coherent = device_get_dma_attr(&pdev->dev) == DEV_DMA_COHERENT;
-
- err = panfrost_device_init(pfdev);
- if (err) {
- if (err != -EPROBE_DEFER)
- dev_err(&pdev->dev, "Fatal error during GPU init\n");
- goto err_out0;
- }
-
- pm_runtime_set_active(pfdev->base.dev);
- pm_runtime_mark_last_busy(pfdev->base.dev);
- pm_runtime_get_noresume(pfdev->base.dev);
- pm_runtime_enable(pfdev->base.dev);
- pm_runtime_set_autosuspend_delay(pfdev->base.dev, 50); /* ~3 frames */
- pm_runtime_use_autosuspend(pfdev->base.dev);
-
- /*
- * Register the DRM device with the core and the connectors with
- * sysfs
- */
- err = drm_dev_register(&pfdev->base, 0);
- if (err < 0)
- goto err_out1;
-
- pm_runtime_put_autosuspend(pfdev->base.dev);
-
- return 0;
-
-err_out1:
- pm_runtime_dont_use_autosuspend(pfdev->base.dev);
- pm_runtime_disable(pfdev->base.dev);
- pm_runtime_put_noidle(pfdev->base.dev);
- pm_runtime_set_suspended(pfdev->base.dev);
- panfrost_device_fini(pfdev);
-err_out0:
- return err;
+ return panfrost_device_init(pfdev);
}

static void panfrost_remove(struct platform_device *pdev)
@@ -887,11 +847,6 @@ static void panfrost_remove(struct platform_device *pdev)

drm_dev_unregister(&pfdev->base);

- pm_runtime_get_sync(pfdev->base.dev);
- pm_runtime_dont_use_autosuspend(pfdev->base.dev);
- pm_runtime_put_noidle(pfdev->base.dev);
- pm_runtime_disable(pfdev->base.dev);
- pm_runtime_set_suspended(pfdev->base.dev);
panfrost_device_fini(pfdev);
}


--
2.55.0