[PATCH] drm/managed: Cleanup of unused functions and polishing docs
Daniel Vetter
daniel.vetter at ffwll.ch
Tue Apr 28 18:51:01 UTC 2020
Following functions are only used internally, not by drivers:
- devm_drm_dev_init
Also, now that we have a very slick and polished way to allocate a
drm_device with devm_drm_dev_alloc, update all the docs to reflect the
new reality. Mostly this consists of deleting old and misleading
hints. Two main ones:
- it is no longer required that the drm_device base class is first in
the structure. devm_drm_dev_alloc can cope with it being anywhere
- obviously embedded now strongly recommends using devm_drm_dev_alloc
v2: Fix typos (Noralf)
v3: Split out the removal of drm_dev_init, that's blocked on some
discussions on how to convert vgem/vkms/i915-selftests. Adjust commit
message to reflect that.
Cc: Noralf Trønnes <noralf at tronnes.org>
Acked-by: Noralf Trønnes <noralf at tronnes.org> (v2)
Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
---
Since the final few cleanups are stuck in further discussions I've split
up the kerneldoc patch at the end so we can land at least the new overview
and all that. Removal of drm_dev_init will have to wait for later on, or
maybe it'll stay around. That all depends upon the drivers/base discussion
and what'll happen with vkms/vgem and i915 selftests.
-Daniel
---
.../driver-api/driver-model/devres.rst | 2 +-
drivers/gpu/drm/drm_drv.c | 78 +++++--------------
drivers/gpu/drm/drm_managed.c | 2 +-
include/drm/drm_device.h | 2 +-
include/drm/drm_drv.h | 16 ++--
5 files changed, 30 insertions(+), 70 deletions(-)
diff --git a/Documentation/driver-api/driver-model/devres.rst b/Documentation/driver-api/driver-model/devres.rst
index 46c13780994c..74a4a3fa8c52 100644
--- a/Documentation/driver-api/driver-model/devres.rst
+++ b/Documentation/driver-api/driver-model/devres.rst
@@ -263,7 +263,7 @@ DMA
dmam_pool_destroy()
DRM
- devm_drm_dev_init()
+ devm_drm_dev_alloc()
GPIO
devm_gpiod_get()
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index 8e1813d2a12e..7018d923fafe 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -240,13 +240,13 @@ void drm_minor_release(struct drm_minor *minor)
* DOC: driver instance overview
*
* A device instance for a drm driver is represented by &struct drm_device. This
- * is initialized with drm_dev_init(), usually from bus-specific ->probe()
- * callbacks implemented by the driver. The driver then needs to initialize all
- * the various subsystems for the drm device like memory management, vblank
- * handling, modesetting support and intial output configuration plus obviously
- * initialize all the corresponding hardware bits. Finally when everything is up
- * and running and ready for userspace the device instance can be published
- * using drm_dev_register().
+ * is allocated and initialized with devm_drm_dev_alloc(), usually from
+ * bus-specific ->probe() callbacks implemented by the driver. The driver then
+ * needs to initialize all the various subsystems for the drm device like memory
+ * management, vblank handling, modesetting support and initial output
+ * configuration plus obviously initialize all the corresponding hardware bits.
+ * Finally when everything is up and running and ready for userspace the device
+ * instance can be published using drm_dev_register().
*
* There is also deprecated support for initalizing device instances using
* bus-specific helpers and the &drm_driver.load callback. But due to
@@ -274,7 +274,7 @@ void drm_minor_release(struct drm_minor *minor)
*
* The following example shows a typical structure of a DRM display driver.
* The example focus on the probe() function and the other functions that is
- * almost always present and serves as a demonstration of devm_drm_dev_init().
+ * almost always present and serves as a demonstration of devm_drm_dev_alloc().
*
* .. code-block:: c
*
@@ -294,22 +294,12 @@ void drm_minor_release(struct drm_minor *minor)
* struct drm_device *drm;
* int ret;
*
- * // devm_kzalloc() can't be used here because the drm_device '
- * // lifetime can exceed the device lifetime if driver unbind
- * // happens when userspace still has open file descriptors.
- * priv = kzalloc(sizeof(*priv), GFP_KERNEL);
- * if (!priv)
- * return -ENOMEM;
- *
+ * priv = devm_drm_dev_alloc(&pdev->dev, &driver_drm_driver,
+ * struct driver_device, drm);
+ * if (IS_ERR(priv))
+ * return PTR_ERR(priv);
* drm = &priv->drm;
*
- * ret = devm_drm_dev_init(&pdev->dev, drm, &driver_drm_driver);
- * if (ret) {
- * kfree(priv);
- * return ret;
- * }
- * drmm_add_final_kfree(drm, priv);
- *
* ret = drmm_mode_config_init(drm);
* if (ret)
* return ret;
@@ -550,9 +540,9 @@ static void drm_fs_inode_free(struct inode *inode)
* following guidelines apply:
*
* - The entire device initialization procedure should be run from the
- * &component_master_ops.master_bind callback, starting with drm_dev_init(),
- * then binding all components with component_bind_all() and finishing with
- * drm_dev_register().
+ * &component_master_ops.master_bind callback, starting with
+ * devm_drm_dev_alloc(), then binding all components with
+ * component_bind_all() and finishing with drm_dev_register().
*
* - The opaque pointer passed to all components through component_bind_all()
* should point at &struct drm_device of the device instance, not some driver
@@ -706,24 +696,9 @@ static void devm_drm_dev_init_release(void *data)
drm_dev_put(data);
}
-/**
- * devm_drm_dev_init - Resource managed drm_dev_init()
- * @parent: Parent device object
- * @dev: DRM device
- * @driver: DRM driver
- *
- * Managed drm_dev_init(). The DRM device initialized with this function is
- * automatically put on driver detach using drm_dev_put().
- *
- * Note that drivers must call drmm_add_final_kfree() after this function has
- * completed successfully.
- *
- * RETURNS:
- * 0 on success, or error code on failure.
- */
-int devm_drm_dev_init(struct device *parent,
- struct drm_device *dev,
- struct drm_driver *driver)
+static int devm_drm_dev_init(struct device *parent,
+ struct drm_device *dev,
+ struct drm_driver *driver)
{
int ret;
@@ -737,7 +712,6 @@ int devm_drm_dev_init(struct device *parent,
return ret;
}
-EXPORT_SYMBOL(devm_drm_dev_init);
void *__devm_drm_dev_alloc(struct device *parent, struct drm_driver *driver,
size_t size, size_t offset)
@@ -767,19 +741,9 @@ EXPORT_SYMBOL(__devm_drm_dev_alloc);
* @driver: DRM driver to allocate device for
* @parent: Parent device object
*
- * Allocate and initialize a new DRM device. No device registration is done.
- * Call drm_dev_register() to advertice the device to user space and register it
- * with other core subsystems. This should be done last in the device
- * initialization sequence to make sure userspace can't access an inconsistent
- * state.
- *
- * The initial ref-count of the object is 1. Use drm_dev_get() and
- * drm_dev_put() to take and drop further ref-counts.
- *
- * Note that for purely virtual devices @parent can be NULL.
- *
- * Drivers that wish to subclass or embed &struct drm_device into their
- * own struct should look at using drm_dev_init() instead.
+ * This is the deprecated version of devm_drm_dev_alloc(), which does not support
+ * subclassing through embedding the struct &drm_device in a driver private
+ * structure, and which does not support automatic cleanup through devres.
*
* RETURNS:
* Pointer to new DRM device, or ERR_PTR on failure.
diff --git a/drivers/gpu/drm/drm_managed.c b/drivers/gpu/drm/drm_managed.c
index 9cebfe370a65..61cf474d1570 100644
--- a/drivers/gpu/drm/drm_managed.c
+++ b/drivers/gpu/drm/drm_managed.c
@@ -25,7 +25,7 @@
* be done directly with drmm_kmalloc() and the related functions. Everything
* will be released on the final drm_dev_put() in reverse order of how the
* release actions have been added and memory has been allocated since driver
- * loading started with drm_dev_init().
+ * loading started with devm_drm_dev_alloc().
*
* Note that release actions and managed memory can also be added and removed
* during the lifetime of the driver, all the functions are fully concurrent
diff --git a/include/drm/drm_device.h b/include/drm/drm_device.h
index a55874db9dd4..ee9e20ce9b85 100644
--- a/include/drm/drm_device.h
+++ b/include/drm/drm_device.h
@@ -92,7 +92,7 @@ struct drm_device {
* NULL.
*
* Instead of using this pointer it is recommended that drivers use
- * drm_dev_init() and embed struct &drm_device in their larger
+ * devm_drm_dev_alloc() and embed struct &drm_device in their larger
* per-device structure.
*/
void *dev_private;
diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h
index f07f15721254..cb5def00d843 100644
--- a/include/drm/drm_drv.h
+++ b/include/drm/drm_drv.h
@@ -163,13 +163,12 @@ struct drm_driver {
/**
* @load:
*
- * Backward-compatible driver callback to complete
- * initialization steps after the driver is registered. For
- * this reason, may suffer from race conditions and its use is
- * deprecated for new drivers. It is therefore only supported
- * for existing drivers not yet converted to the new scheme.
- * See drm_dev_init() and drm_dev_register() for proper and
- * race-free way to set up a &struct drm_device.
+ * Backward-compatible driver callback to complete initialization steps
+ * after the driver is registered. For this reason, may suffer from
+ * race conditions and its use is deprecated for new drivers. It is
+ * therefore only supported for existing drivers not yet converted to
+ * the new scheme. See devm_drm_dev_alloc() and drm_dev_register() for
+ * proper and race-free way to set up a &struct drm_device.
*
* This is deprecated, do not use!
*
@@ -622,9 +621,6 @@ struct drm_driver {
int drm_dev_init(struct drm_device *dev,
struct drm_driver *driver,
struct device *parent);
-int devm_drm_dev_init(struct device *parent,
- struct drm_device *dev,
- struct drm_driver *driver);
void *__devm_drm_dev_alloc(struct device *parent, struct drm_driver *driver,
size_t size, size_t offset);
--
2.25.1
More information about the dri-devel
mailing list