Messages in this thread Patch in this message | | | Date | Tue, 27 Jun 2023 17:04:42 +0800 | Subject | Re: [PATCH] drm: Remove the deprecated drm_put_dev() function | From | Sui Jingfeng <> |
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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
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