linux/drivers/gpu/drm/drm_platform.c
Dave Airlie b64c115eb2 drm: fix race between driver loading and userspace open.
Not 100% sure this is due to BKL removal, its most likely a combination
of that + userspace timing changes in udev/plymouth. The drm adds the sysfs
device before the driver has completed internal loading, this causes udev
to make the node and plymouth to open it before we've completed loading.

The proper solution is to delay the sysfs manipulation until later in loading
however this causes knock on issues with sysfs connector nodes, so we can use
the global mutex to serialise loading and userspace opens.

Reported-by: Toni Spets (hifi on #radeon)
Signed-off-by: Dave Airlie <airlied@redhat.com>
2010-09-14 20:39:04 +10:00

127 lines
3.5 KiB
C

/*
* Derived from drm_pci.c
*
* Copyright 2003 José Fonseca.
* Copyright 2003 Leif Delgass.
* Copyright (c) 2009, Code Aurora Forum.
* All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#include "drmP.h"
/**
* Register.
*
* \param platdev - Platform device struture
* \return zero on success or a negative number on failure.
*
* Attempt to gets inter module "drm" information. If we are first
* then register the character device and inter module information.
* Try and register, if we fail to register, backout previous work.
*/
int drm_get_platform_dev(struct platform_device *platdev,
struct drm_driver *driver)
{
struct drm_device *dev;
int ret;
DRM_DEBUG("\n");
dev = kzalloc(sizeof(*dev), GFP_KERNEL);
if (!dev)
return -ENOMEM;
dev->platformdev = platdev;
dev->dev = &platdev->dev;
mutex_lock(&drm_global_mutex);
ret = drm_fill_in_dev(dev, NULL, driver);
if (ret) {
printk(KERN_ERR "DRM: Fill_in_dev failed.\n");
goto err_g1;
}
if (drm_core_check_feature(dev, DRIVER_MODESET)) {
dev_set_drvdata(&platdev->dev, dev);
ret = drm_get_minor(dev, &dev->control, DRM_MINOR_CONTROL);
if (ret)
goto err_g1;
}
ret = drm_get_minor(dev, &dev->primary, DRM_MINOR_LEGACY);
if (ret)
goto err_g2;
if (dev->driver->load) {
ret = dev->driver->load(dev, 0);
if (ret)
goto err_g3;
}
/* setup the grouping for the legacy output */
if (drm_core_check_feature(dev, DRIVER_MODESET)) {
ret = drm_mode_group_init_legacy_group(dev,
&dev->primary->mode_group);
if (ret)
goto err_g3;
}
list_add_tail(&dev->driver_item, &driver->device_list);
mutex_unlock(&drm_global_mutex);
DRM_INFO("Initialized %s %d.%d.%d %s on minor %d\n",
driver->name, driver->major, driver->minor, driver->patchlevel,
driver->date, dev->primary->index);
return 0;
err_g3:
drm_put_minor(&dev->primary);
err_g2:
if (drm_core_check_feature(dev, DRIVER_MODESET))
drm_put_minor(&dev->control);
err_g1:
kfree(dev);
mutex_unlock(&drm_global_mutex);
return ret;
}
EXPORT_SYMBOL(drm_get_platform_dev);
/**
* Platform device initialization. Called via drm_init at module load time,
*
* \return zero on success or a negative number on failure.
*
* Initializes a drm_device structures,registering the
* stubs
*
* Expands the \c DRIVER_PREINIT and \c DRIVER_POST_INIT macros before and
* after the initialization for driver customization.
*/
int drm_platform_init(struct drm_driver *driver)
{
return drm_get_platform_dev(driver->platform_device, driver);
}