Also note that it is not currently feasible for UDL code to access drm_global_mutex.
Please also refer to the similar comments ("FIXME: open_count is protected by drm_global_mutex but that would lead to locking inversion with the driver load path.") in nouveau, i915 and amdgpu.
On Wed, Feb 10, 2016 at 12:51 PM, Haixia Shi hshi@chromium.org wrote:
This should rather be:
drm_release(inode, filp); mutex_lock(&drm_global_mutex); if (!dev->open_count && udl_device_is_unplugged(dev)) drm_put_dev(dev); mutex_unlock(&drm_global_mutex); return 0;There is no reason to look at the return code of drm_release(), ever.
But drm_release() does return a retcode. It would still make sense to return that as-is in case any existing code relies on it.
On Wed, Feb 10, 2016 at 4:24 AM, David Herrmann dh.herrmann@gmail.com wrote:
Hi
On Tue, Feb 9, 2016 at 10:05 PM, Haixia Shi hshi@chromium.org wrote:
Remove the general drm_device_is_unplugged() checks, and move the
unplugged
flag handling logic into drm/udl. In general we want to keep
driver-specific
logic out of common drm code.
Signed-off-by: Haixia Shi hshi@chromium.org Reviewed-by: Stéphane Marchesin marcheu@chromium.org
drivers/gpu/drm/drm_drv.c | 6 ---- drivers/gpu/drm/drm_fops.c | 2 -- drivers/gpu/drm/drm_gem.c | 3 -- drivers/gpu/drm/drm_ioctl.c | 3 -- drivers/gpu/drm/drm_vm.c | 3 -- drivers/gpu/drm/udl/udl_connector.c | 2 +- drivers/gpu/drm/udl/udl_drv.c | 7 +++-- drivers/gpu/drm/udl/udl_drv.h | 6 ++++ drivers/gpu/drm/udl/udl_fb.c | 2 +- drivers/gpu/drm/udl/udl_gem.c | 5 +++ drivers/gpu/drm/udl/udl_main.c | 61
+++++++++++++++++++++++++++++++++++++
include/drm/drmP.h | 14 --------- 12 files changed, 78 insertions(+), 36 deletions(-)
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c index 167c8d3..f93ee12 100644 --- a/drivers/gpu/drm/drm_drv.c +++ b/drivers/gpu/drm/drm_drv.c @@ -376,9 +376,6 @@ struct drm_minor *drm_minor_acquire(unsigned int
minor_id)
if (!minor) { return ERR_PTR(-ENODEV);
} else if (drm_device_is_unplugged(minor->dev)) {drm_dev_unref(minor->dev);return ERR_PTR(-ENODEV); } return minor;@@ -464,9 +461,6 @@ void drm_unplug_dev(struct drm_device *dev) drm_minor_unregister(dev, DRM_MINOR_CONTROL);
mutex_lock(&drm_global_mutex);
drm_device_set_unplugged(dev);if (dev->open_count == 0) { drm_put_dev(dev); }diff --git a/drivers/gpu/drm/drm_fops.c b/drivers/gpu/drm/drm_fops.c index 1ea8790..b4332d4 100644 --- a/drivers/gpu/drm/drm_fops.c +++ b/drivers/gpu/drm/drm_fops.c @@ -497,8 +497,6 @@ int drm_release(struct inode *inode, struct file
*filp)
if (!--dev->open_count) { retcode = drm_lastclose(dev);
if (drm_device_is_unplugged(dev))drm_put_dev(dev); } mutex_unlock(&drm_global_mutex);diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c index 2e8c77e..c622e32 100644 --- a/drivers/gpu/drm/drm_gem.c +++ b/drivers/gpu/drm/drm_gem.c @@ -900,9 +900,6 @@ int drm_gem_mmap(struct file *filp, struct
vm_area_struct *vma)
struct drm_vma_offset_node *node; int ret;
if (drm_device_is_unplugged(dev))return -ENODEV;drm_vma_offset_lock_lookup(dev->vma_offset_manager); node =drm_vma_offset_exact_lookup_locked(dev->vma_offset_manager,
vma->vm_pgoff,diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c index 8ce2a0c..f959074 100644 --- a/drivers/gpu/drm/drm_ioctl.c +++ b/drivers/gpu/drm/drm_ioctl.c @@ -695,9 +695,6 @@ long drm_ioctl(struct file *filp,
dev = file_priv->minor->dev;
if (drm_device_is_unplugged(dev))return -ENODEV;is_driver_ioctl = nr >= DRM_COMMAND_BASE && nr <DRM_COMMAND_END;
if (is_driver_ioctl) {diff --git a/drivers/gpu/drm/drm_vm.c b/drivers/gpu/drm/drm_vm.c index f90bd5f..3a68be4 100644 --- a/drivers/gpu/drm/drm_vm.c +++ b/drivers/gpu/drm/drm_vm.c @@ -657,9 +657,6 @@ int drm_legacy_mmap(struct file *filp, struct
vm_area_struct *vma)
struct drm_device *dev = priv->minor->dev; int ret;
if (drm_device_is_unplugged(dev))return -ENODEV;mutex_lock(&dev->struct_mutex); ret = drm_mmap_locked(filp, vma); mutex_unlock(&dev->struct_mutex);diff --git a/drivers/gpu/drm/udl/udl_connector.c
b/drivers/gpu/drm/udl/udl_connector.c
index 4709b54..b168f2c 100644 --- a/drivers/gpu/drm/udl/udl_connector.c +++ b/drivers/gpu/drm/udl/udl_connector.c @@ -96,7 +96,7 @@ static int udl_mode_valid(struct drm_connector
*connector,
static enum drm_connector_status udl_detect(struct drm_connector *connector, bool force) {
if (drm_device_is_unplugged(connector->dev))
if (udl_device_is_unplugged(connector->dev)) return connector_status_disconnected; return connector_status_connected;} diff --git a/drivers/gpu/drm/udl/udl_drv.c
b/drivers/gpu/drm/udl/udl_drv.c
index d5728ec..f5c2a97 100644 --- a/drivers/gpu/drm/udl/udl_drv.c +++ b/drivers/gpu/drm/udl/udl_drv.c @@ -24,12 +24,12 @@ static const struct vm_operations_struct
udl_gem_vm_ops = {
static const struct file_operations udl_driver_fops = { .owner = THIS_MODULE,
.open = drm_open,
.open = udl_drm_open, .mmap = udl_drm_gem_mmap, .poll = drm_poll, .read = drm_read,
.unlocked_ioctl = drm_ioctl,.release = drm_release,
.unlocked_ioctl = udl_drm_ioctl,.release = udl_drm_release,#ifdef CONFIG_COMPAT .compat_ioctl = drm_compat_ioctl, #endif @@ -97,6 +97,7 @@ static void udl_usb_disconnect(struct usb_interface
*interface)
drm_connector_unplug_all(dev); udl_fbdev_unplug(dev); udl_drop_usb(dev);
udl_device_set_unplugged(dev); drm_unplug_dev(dev);}
diff --git a/drivers/gpu/drm/udl/udl_drv.h
b/drivers/gpu/drm/udl/udl_drv.h
index 4a064ef..75aa91c 100644 --- a/drivers/gpu/drm/udl/udl_drv.h +++ b/drivers/gpu/drm/udl/udl_drv.h @@ -65,6 +65,7 @@ struct udl_device { atomic_t bytes_identical; /* saved effort with backbuffer
comparison */
atomic_t bytes_sent; /* to usb, after compression includingoverhead */
atomic_t cpu_kcycles_used; /* transpired during pixelprocessing */
atomic_t unplugged; /* device has been unplugged or gone away */};
struct udl_gem_object { @@ -133,6 +134,9 @@ int udl_gem_get_pages(struct udl_gem_object *obj); void udl_gem_put_pages(struct udl_gem_object *obj); int udl_gem_vmap(struct udl_gem_object *obj); void udl_gem_vunmap(struct udl_gem_object *obj); +int udl_drm_open(struct inode *inode, struct file *filp); +int udl_drm_release(struct inode *inode, struct file *filp); +int udl_drm_ioctl(struct file *filp, unsigned int cmd, unsigned long
arg);
int udl_drm_gem_mmap(struct file *filp, struct vm_area_struct *vma); int udl_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf);
@@ -140,6 +144,8 @@ int udl_handle_damage(struct udl_framebuffer *fb,
int x, int y,
int width, int height);int udl_drop_usb(struct drm_device *dev); +void udl_device_set_unplugged(struct drm_device *dev); +int udl_device_is_unplugged(struct drm_device *dev);
#define CMD_WRITE_RAW8 "\xAF\x60" /**< 8 bit raw write command. */ #define CMD_WRITE_RL8 "\xAF\x61" /**< 8 bit run length command. */ diff --git a/drivers/gpu/drm/udl/udl_fb.c b/drivers/gpu/drm/udl/udl_fb.c index 200419d..df1d53e 100644 --- a/drivers/gpu/drm/udl/udl_fb.c +++ b/drivers/gpu/drm/udl/udl_fb.c @@ -325,7 +325,7 @@ static int udl_fb_open(struct fb_info *info, int
user)
struct udl_device *udl = dev->dev_private; /* If the USB device is gone, we don't accept new opens */
if (drm_device_is_unplugged(udl->ddev))
if (udl_device_is_unplugged(udl->ddev)) return -ENODEV; ufbdev->fb_count++;diff --git a/drivers/gpu/drm/udl/udl_gem.c
b/drivers/gpu/drm/udl/udl_gem.c
index 2a0a784..33c302f 100644 --- a/drivers/gpu/drm/udl/udl_gem.c +++ b/drivers/gpu/drm/udl/udl_gem.c @@ -86,8 +86,13 @@ int udl_dumb_create(struct drm_file *file,
int udl_drm_gem_mmap(struct file *filp, struct vm_area_struct *vma) {
struct drm_file *priv = filp->private_data;struct drm_device *dev = priv->minor->dev; int ret;if (udl_device_is_unplugged(dev))return -ENODEV;ret = drm_gem_mmap(filp, vma); if (ret) return ret;diff --git a/drivers/gpu/drm/udl/udl_main.c
b/drivers/gpu/drm/udl/udl_main.c
index 33dbfb2..2ba3ee3 100644 --- a/drivers/gpu/drm/udl/udl_main.c +++ b/drivers/gpu/drm/udl/udl_main.c @@ -350,3 +350,64 @@ int udl_driver_unload(struct drm_device *dev) kfree(udl); return 0; }
+int udl_drm_open(struct inode *inode, struct file *filp) +{
struct drm_file *file_priv;struct drm_minor *minor;int ret = drm_open(inode, filp);if (ret)return ret;file_priv = filp->private_data;minor = file_priv->minor;if (udl_device_is_unplugged(minor->dev)) {drm_dev_unref(minor->dev);return -ENODEV;}This doesn't make sense to me. You're called here with global-mutex held, so you can just check udl_device_is_unplugged() before calling into drm_open().
return 0;+}
+int udl_drm_release(struct inode *inode, struct file *filp) +{
struct drm_file *file_priv = filp->private_data;struct drm_device *dev = file_priv->minor->dev;int ret = drm_release(inode, filp);if (!dev->open_count && udl_device_is_unplugged(dev))drm_put_dev(dev);This should rather be:
drm_release(inode, filp); mutex_lock(&drm_global_mutex); if (!dev->open_count && udl_device_is_unplugged(dev)) drm_put_dev(dev); mutex_unlock(&drm_global_mutex); return 0;There is no reason to look at the return code of drm_release(), ever.
return ret;+}
+int udl_drm_ioctl(struct file *filp, unsigned int cmd, unsigned long
arg)
+{
struct drm_file *file_priv = filp->private_data;struct drm_device *dev = file_priv->minor->dev;unsigned int nr = DRM_IOCTL_NR(cmd);if (udl_device_is_unplugged(dev) &&nr != DRM_IOCTL_NR(DRM_IOCTL_MODE_SETCRTC) &&nr != DRM_IOCTL_NR(DRM_IOCTL_MODE_RMFB) &&nr != DRM_IOCTL_NR(DRM_IOCTL_MODE_DESTROY_DUMB))return -ENODEV;Why?
Just do:
if (udl_device_is_unplugged(dev)) return -ENODEV;Why this complex logic here?
Thanks David
return drm_ioctl(filp, cmd, arg);+}
+void udl_device_set_unplugged(struct drm_device *dev) +{
struct udl_device *udl = dev->dev_private;smp_wmb();atomic_set(&udl->unplugged, 1);+}
+int udl_device_is_unplugged(struct drm_device *dev) +{
struct udl_device *udl = dev->dev_private;int ret = atomic_read(&udl->unplugged);smp_rmb();return ret;+} diff --git a/include/drm/drmP.h b/include/drm/drmP.h index d7162cf..40c6099 100644 --- a/include/drm/drmP.h +++ b/include/drm/drmP.h @@ -748,7 +748,6 @@ struct drm_device { struct drm_minor *control; /**< Control node */ struct drm_minor *primary; /**< Primary node */ struct drm_minor *render; /**< Render node */
atomic_t unplugged; /**< Flag whether devis dead */
struct inode *anon_inode; /**< inode for privateaddress-space */
char *unique; /**< unique name of thedevice */
/*@} */@@ -879,19 +878,6 @@ static __inline__ int
drm_core_check_feature(struct drm_device *dev,
return ((dev->driver->driver_features & feature) ? 1 : 0);}
-static inline void drm_device_set_unplugged(struct drm_device *dev) -{
smp_wmb();atomic_set(&dev->unplugged, 1);-}
-static inline int drm_device_is_unplugged(struct drm_device *dev) -{
int ret = atomic_read(&dev->unplugged);smp_rmb();return ret;-}
static inline bool drm_is_render_client(const struct drm_file
*file_priv)
{ return file_priv->minor->type == DRM_MINOR_RENDER; -- 2.7.0.rc3.207.g0ac5344