diff options
author | Daniel Vetter <daniel.vetter@ffwll.ch> | 2020-03-23 15:49:25 +0100 |
---|---|---|
committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2020-03-26 15:45:43 +0100 |
commit | c3b790ea07a13da0c46816bda6b04abef346af15 (patch) | |
tree | 7ff7b1ad8407e35767e151c92427218b013f809d /drivers/gpu/drm/drm_drv.c | |
parent | d33b58d0115e7eee011fddee2d8e25c6a09fb279 (diff) | |
download | linux-c3b790ea07a13da0c46816bda6b04abef346af15.tar.bz2 |
drm: Manage drm_mode_config_init with drmm_
drm_mode_config_cleanup is idempotent, so no harm in calling this
twice. This allows us to gradually switch drivers over by removing
explicit drm_mode_config_cleanup calls.
With this step it's now also possible that (at least for simple
drivers) automatic resource cleanup can be done correctly without a
drm_driver->release hook. Therefore allow this now in
devm_drm_dev_init().
Also with drmm_ explicit drm_driver->release hooks are kinda not the
best option: Drivers can always just register their current release
hook with drmm_add_action, but even better they could split them up to
simplify the unwinding for the driver load failure case. So deprecate
that hook to discourage future users.
v2: Fixup the example in the kerneldoc too.
v3:
- For paranoia, double check that minor->dev == dev in the release
hook, because I botched the pointer math in the drmm library.
- Call drm_mode_config_cleanup when drmm_add_action fails, we'd be
missing some mutex_destroy and ida_cleanup otherwise (Laurent)
v4: Add a drmm_add_action_or_reset (like devm_ has) to encapsulate this
pattern (Noralf).
v5: Fix oversight in the new drmm_add_action_or_reset macro (Noralf)
v4: Review from Sam:
- drmm_mode_config_init wrapper (also suggested by Thomas)
- improve commit message, explain better why ->relase is deprecated
v5:
- Make drmm_ the main function, with the old one as compat wrapper
(Sam)
- Add FIXME comments to drm_mode_config_cleanup/init() that drivers
shouldn't use these anymore.
- Move drmm_add_action_or_reset helper to an earlier patch.
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: "Noralf Trønnes" <noralf@tronnes.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Noralf Trønnes <noralf@tronnes.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200323144950.3018436-27-daniel.vetter@ffwll.ch
Diffstat (limited to 'drivers/gpu/drm/drm_drv.c')
-rw-r--r-- | drivers/gpu/drm/drm_drv.c | 23 |
1 files changed, 7 insertions, 16 deletions
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c index c36687840f4e..158fea71371b 100644 --- a/drivers/gpu/drm/drm_drv.c +++ b/drivers/gpu/drm/drm_drv.c @@ -98,6 +98,8 @@ static void drm_minor_alloc_release(struct drm_device *dev, void *data) struct drm_minor *minor = data; unsigned long flags; + WARN_ON(dev != minor->dev); + put_device(minor->kdev); spin_lock_irqsave(&drm_minor_lock, flags); @@ -266,8 +268,7 @@ 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() - * usage with its accompanying drm_driver->release callback. + * almost always present and serves as a demonstration of devm_drm_dev_init(). * * .. code-block:: c * @@ -277,16 +278,8 @@ void drm_minor_release(struct drm_minor *minor) * struct clk *pclk; * }; * - * static void driver_drm_release(struct drm_device *drm) - * { - * struct driver_device *priv = container_of(...); - * - * drm_mode_config_cleanup(drm); - * } - * * static struct drm_driver driver_drm_driver = { * [...] - * .release = driver_drm_release, * }; * * static int driver_probe(struct platform_device *pdev) @@ -311,7 +304,9 @@ void drm_minor_release(struct drm_minor *minor) * } * drmm_add_final_kfree(drm, priv); * - * drm_mode_config_init(drm); + * ret = drmm_mode_config_init(drm); + * if (ret) + * return ret; * * priv->userspace_facing = drmm_kzalloc(..., GFP_KERNEL); * if (!priv->userspace_facing) @@ -709,8 +704,7 @@ static void devm_drm_dev_init_release(void *data) * @driver: DRM driver * * Managed drm_dev_init(). The DRM device initialized with this function is - * automatically put on driver detach using drm_dev_put(). You must supply a - * &drm_driver.release callback to control the finalization explicitly. + * automatically put on driver detach using drm_dev_put(). * * RETURNS: * 0 on success, or error code on failure. @@ -721,9 +715,6 @@ int devm_drm_dev_init(struct device *parent, { int ret; - if (WARN_ON(!driver->release)) - return -EINVAL; - ret = drm_dev_init(dev, driver, parent); if (ret) return ret; |