lkml.org 
[lkml]   [2023]   [Jun]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
SubjectRe: [PATCH] drm: Remove the deprecated drm_put_dev() function
From
Hi,

On 2023/6/26 15:48, Jani Nikula wrote:
> On Sun, 25 Jun 2023, Sui Jingfeng <suijingfeng@loongson.cn> wrote:
>> As this function can be replaced with drm_dev_unregister() + drm_dev_put(),
>> it is already marked as deprecated, so remove it. No functional change.
>>
>> Signed-off-by: Sui Jingfeng <suijingfeng@loongson.cn>
>> ---
>> drivers/gpu/drm/drm_drv.c | 28 ----------------------------
>> drivers/gpu/drm/drm_pci.c | 3 ++-
>> drivers/gpu/drm/radeon/radeon_drv.c | 3 ++-
>> include/drm/drm_drv.h | 1 -
>> 4 files changed, 4 insertions(+), 31 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
>> index 12687dd9e1ac..5057307fe22a 100644
>> --- a/drivers/gpu/drm/drm_drv.c
>> +++ b/drivers/gpu/drm/drm_drv.c
>> @@ -406,34 +406,6 @@ void drm_minor_release(struct drm_minor *minor)
>> * possibly leaving the hardware enabled.
>> */
>>
>> -/**
>> - * drm_put_dev - Unregister and release a DRM device
>> - * @dev: DRM device
>> - *
>> - * Called at module unload time or when a PCI device is unplugged.
>> - *
>> - * Cleans up all DRM device, calling drm_lastclose().
>> - *
>> - * Note: Use of this function is deprecated. It will eventually go away
>> - * completely. Please use drm_dev_unregister() and drm_dev_put() explicitly
>> - * instead to make sure that the device isn't userspace accessible any more
>> - * while teardown is in progress, ensuring that userspace can't access an
>> - * inconsistent state.
> The last sentence is the crucial one. While the patch has no functional
> changes,

But my patch help to save a useless check(if (!dev))

on where we found the check is not necessary.

```

- if (!dev) {
- DRM_ERROR("cleanup called no dev\n");
- return;
- }

```


> I believe the goal never was to just mechanically replace one
> call with the two.

The DRM core lose nothing, just a function wrapper.

Instead, this is probably a good chance to migrate the burden to the
driver side.

I think the device driver(drm/radeon, for example) have better understanding

about how to ensure that userspace can't access an inconsistent state
than the DRM core.

>
> BR,
> Jani.
>
>
>> - */
>> -void drm_put_dev(struct drm_device *dev)
>> -{
>> - DRM_DEBUG("\n");
>> -
>> - if (!dev) {
>> - DRM_ERROR("cleanup called no dev\n");
>> - return;
>> - }
>> -
>> - drm_dev_unregister(dev);
>> - drm_dev_put(dev);
>> -}
>> -EXPORT_SYMBOL(drm_put_dev);
>> -
>> /**
>> * drm_dev_enter - Enter device critical section
>> * @dev: DRM device
>> diff --git a/drivers/gpu/drm/drm_pci.c b/drivers/gpu/drm/drm_pci.c
>> index 39d35fc3a43b..b3a68a92eaa6 100644
>> --- a/drivers/gpu/drm/drm_pci.c
>> +++ b/drivers/gpu/drm/drm_pci.c
>> @@ -257,7 +257,8 @@ void drm_legacy_pci_exit(const struct drm_driver *driver,
>> legacy_dev_list) {
>> if (dev->driver == driver) {
>> list_del(&dev->legacy_dev_list);
>> - drm_put_dev(dev);
>> + drm_dev_unregister(dev);
>> + drm_dev_put(dev);
>> }
>> }
>> mutex_unlock(&legacy_dev_list_lock);
>> diff --git a/drivers/gpu/drm/radeon/radeon_drv.c b/drivers/gpu/drm/radeon/radeon_drv.c
>> index e4374814f0ef..a4955ae10659 100644
>> --- a/drivers/gpu/drm/radeon/radeon_drv.c
>> +++ b/drivers/gpu/drm/radeon/radeon_drv.c
>> @@ -357,7 +357,8 @@ radeon_pci_remove(struct pci_dev *pdev)
>> {
>> struct drm_device *dev = pci_get_drvdata(pdev);
>>
>> - drm_put_dev(dev);
>> + drm_dev_unregister(dev);
>> + drm_dev_put(dev);
>> }
>>
>> static void
>> diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h
>> index 89e2706cac56..289c97b12e82 100644
>> --- a/include/drm/drm_drv.h
>> +++ b/include/drm/drm_drv.h
>> @@ -511,7 +511,6 @@ void drm_dev_unregister(struct drm_device *dev);
>>
>> void drm_dev_get(struct drm_device *dev);
>> void drm_dev_put(struct drm_device *dev);
>> -void drm_put_dev(struct drm_device *dev);
>> bool drm_dev_enter(struct drm_device *dev, int *idx);
>> void drm_dev_exit(int idx);
>> void drm_dev_unplug(struct drm_device *dev);

--
Jingfeng

\
 
 \ /
  Last update: 2023-06-27 11:05    [W:0.067 / U:0.820 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site