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drm: Remove dev_pm_ops from drm_class 

The PM core introduced the ability to keep devices runtime suspended
during the entire system suspend/resume process with commit aae4518b31
("PM / sleep: Mechanism to avoid resuming runtime-suspended devices
unnecessarily"). Before this so-called "direct-complete" procedure was
introduced, devices were always runtime resumed only to be immediately
put to sleep again using their ->suspend hook. Direct-complete is
enabled by returning a positive value from the ->prepare hook. The PCI
core usually does this automatically.

Direct-complete is only available for a device if all children use it as
well. Currently we cannot support direct-complete for DRM drivers
because the DRM core automatically registers multiple DRM minors which
belong to device class drm_class, and drm_class uses a struct dev_pm_ops
which lacks the ->prepare callback.

While this could be solved by adding the missing ->prepare callback,
closer inspection shows that there are no DRM drivers left which declare
the legacy ->suspend and ->resume callbacks in their drm_driver struct.
The last ones to remove them were i915 with commit 1751fcf9f9
("drm/i915: Fix module initialisation, v2.") and exynos with commit
e7fefb1d5a ("drm/exynos: remove legacy ->suspend()/resume()").

Consequently the struct dev_pm_ops of drm_class is now dead code. Remove
it. If no dev_pm_ops is declared for a device, the PM core automatically
enables direct-complete for it, thereby making that mechanism available
to the parent DRM PCI devices.

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/da848fcd5ca72a35d9a722e644719977a47bb7ba.1465382836.git.lukas@wunner.de
This commit is contained in:
Lukas Wunner 2016-06-08 12:49:29 +02:00 committed by Daniel Vetter
parent 3c85f20a28
commit d14d2a8453
3 changed files with 0 additions and 75 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
drivers/gpu/drm/drm_drv.c
View File

@ -605,8 +605,6 @@ struct drm_device *drm_dev_alloc(struct drm_driver *driver,
ret = drm_minor_alloc(dev, DRM_MINOR_CONTROL);
if (ret)
goto err_minors;
WARN_ON(driver->suspend || driver->resume);
}
if (drm_core_check_feature(dev, DRIVER_RENDER)) {

71
drivers/gpu/drm/drm_sysfs.c
View File

@ -32,75 +32,6 @@ static struct device_type drm_sysfs_device_minor = {
struct class *drm_class;
/**
* __drm_class_suspend - internal DRM class suspend routine
* @dev: Linux device to suspend
* @state: power state to enter
*
* Just figures out what the actual struct drm_device associated with
* @dev is and calls its suspend hook, if present.
*/
static int __drm_class_suspend(struct device *dev, pm_message_t state)
{
if (dev->type == &drm_sysfs_device_minor) {
struct drm_minor *drm_minor = to_drm_minor(dev);
struct drm_device *drm_dev = drm_minor->dev;
if (drm_minor->type == DRM_MINOR_LEGACY &&
!drm_core_check_feature(drm_dev, DRIVER_MODESET) &&
drm_dev->driver->suspend)
return drm_dev->driver->suspend(drm_dev, state);
}
return 0;
}
/**
* drm_class_suspend - internal DRM class suspend hook. Simply calls
* __drm_class_suspend() with the correct pm state.
* @dev: Linux device to suspend
*/
static int drm_class_suspend(struct device *dev)
{
return __drm_class_suspend(dev, PMSG_SUSPEND);
}
/**
* drm_class_freeze - internal DRM class freeze hook. Simply calls
* __drm_class_suspend() with the correct pm state.
* @dev: Linux device to freeze
*/
static int drm_class_freeze(struct device *dev)
{
return __drm_class_suspend(dev, PMSG_FREEZE);
}
/**
* drm_class_resume - DRM class resume hook
* @dev: Linux device to resume
*
* Just figures out what the actual struct drm_device associated with
* @dev is and calls its resume hook, if present.
*/
static int drm_class_resume(struct device *dev)
{
if (dev->type == &drm_sysfs_device_minor) {
struct drm_minor *drm_minor = to_drm_minor(dev);
struct drm_device *drm_dev = drm_minor->dev;
if (drm_minor->type == DRM_MINOR_LEGACY &&
!drm_core_check_feature(drm_dev, DRIVER_MODESET) &&
drm_dev->driver->resume)
return drm_dev->driver->resume(drm_dev);
}
return 0;
}
static const struct dev_pm_ops drm_class_dev_pm_ops = {
.suspend = drm_class_suspend,
.resume = drm_class_resume,
.freeze = drm_class_freeze,
};
static char *drm_devnode(struct device *dev, umode_t *mode)
{
return kasprintf(GFP_KERNEL, "dri/%s", dev_name(dev));
@ -131,8 +62,6 @@ int drm_sysfs_init(void)
if (IS_ERR(drm_class))
return PTR_ERR(drm_class);
drm_class->pm = &drm_class_dev_pm_ops;
err = class_create_file(drm_class, &class_attr_version.attr);
if (err) {
class_destroy(drm_class);

2
include/drm/drmP.h
View File

@ -417,8 +417,6 @@ struct drm_driver {
void (*postclose) (struct drm_device *, struct drm_file *);
void (*lastclose) (struct drm_device *);
int (*unload) (struct drm_device *);
int (*suspend) (struct drm_device *, pm_message_t state);
int (*resume) (struct drm_device *);
int (*dma_ioctl) (struct drm_device *dev, void *data, struct drm_file *file_priv);
int (*dma_quiescent) (struct drm_device *);
int (*context_dtor) (struct drm_device *dev, int context);