linux/drivers/gpu/drm/omapdrm/omap_debugfs.c
Daniel Vetter dfe96ddcfa omapdrm: simplify locking in the fb debugfs file
We don't need to hold onto mode_config.mutex any more to keep the fb
objects around. And locking dev->struct_mutex is also not required,
since omap_gem_describe only reads data anyway. And for a debug
interface it's better to grab fewer locks in case the driver is
deadlocked already ...

The only thing we need is to hold onto mode_config.fb_lock to ensure
the user-created fbs don't disappear. The fbcon fb doesn't need any
protection, since it lives as long as the driver (and so the debugfs
files) itself. And if the teardown/setup isn't following the right
sequence grabbing locks won't prevent a NULL deref on priv->fbdev if
the fb is not yet (or no longer) there.

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Rob Clark <robdclark@gmail.com>
2013-02-16 18:13:26 -05:00

126 lines
3.2 KiB
C

/*
* drivers/gpu/drm/omapdrm/omap_debugfs.c
*
* Copyright (C) 2011 Texas Instruments
* Author: Rob Clark <rob.clark@linaro.org>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "omap_drv.h"
#include "omap_dmm_tiler.h"
#include "drm_fb_helper.h"
#ifdef CONFIG_DEBUG_FS
static int gem_show(struct seq_file *m, void *arg)
{
struct drm_info_node *node = (struct drm_info_node *) m->private;
struct drm_device *dev = node->minor->dev;
struct omap_drm_private *priv = dev->dev_private;
int ret;
ret = mutex_lock_interruptible(&dev->struct_mutex);
if (ret)
return ret;
seq_printf(m, "All Objects:\n");
omap_gem_describe_objects(&priv->obj_list, m);
mutex_unlock(&dev->struct_mutex);
return 0;
}
static int mm_show(struct seq_file *m, void *arg)
{
struct drm_info_node *node = (struct drm_info_node *) m->private;
struct drm_device *dev = node->minor->dev;
return drm_mm_dump_table(m, dev->mm_private);
}
static int fb_show(struct seq_file *m, void *arg)
{
struct drm_info_node *node = (struct drm_info_node *) m->private;
struct drm_device *dev = node->minor->dev;
struct omap_drm_private *priv = dev->dev_private;
struct drm_framebuffer *fb;
seq_printf(m, "fbcon ");
omap_framebuffer_describe(priv->fbdev->fb, m);
mutex_lock(&dev->mode_config.fb_lock);
list_for_each_entry(fb, &dev->mode_config.fb_list, head) {
if (fb == priv->fbdev->fb)
continue;
seq_printf(m, "user ");
omap_framebuffer_describe(fb, m);
}
mutex_unlock(&dev->mode_config.fb_lock);
return 0;
}
/* list of debufs files that are applicable to all devices */
static struct drm_info_list omap_debugfs_list[] = {
{"gem", gem_show, 0},
{"mm", mm_show, 0},
{"fb", fb_show, 0},
};
/* list of debugfs files that are specific to devices with dmm/tiler */
static struct drm_info_list omap_dmm_debugfs_list[] = {
{"tiler_map", tiler_map_show, 0},
};
int omap_debugfs_init(struct drm_minor *minor)
{
struct drm_device *dev = minor->dev;
int ret;
ret = drm_debugfs_create_files(omap_debugfs_list,
ARRAY_SIZE(omap_debugfs_list),
minor->debugfs_root, minor);
if (ret) {
dev_err(dev->dev, "could not install omap_debugfs_list\n");
return ret;
}
if (dmm_is_available())
ret = drm_debugfs_create_files(omap_dmm_debugfs_list,
ARRAY_SIZE(omap_dmm_debugfs_list),
minor->debugfs_root, minor);
if (ret) {
dev_err(dev->dev, "could not install omap_dmm_debugfs_list\n");
return ret;
}
return ret;
}
void omap_debugfs_cleanup(struct drm_minor *minor)
{
drm_debugfs_remove_files(omap_debugfs_list,
ARRAY_SIZE(omap_debugfs_list), minor);
if (dmm_is_available())
drm_debugfs_remove_files(omap_dmm_debugfs_list,
ARRAY_SIZE(omap_dmm_debugfs_list), minor);
}
#endif