On Wed, Feb 10, 2016 at 03:18:38PM -0800, Haixia Shi wrote:
> When USB cable is disconnected, we mark udl device as unplugged so that
> udl_detect reports connector status as disconnected, but still keep
> the drm device alive until user-space closes it.
>
> Signed-off-by: Haixia Shi <hshi at chromium.org>
> Reviewed-by: Stéphane Marchesin <marcheu at chromium.org>
Please add more details capturing the discussion, i.e. why exactly this
was done. Also, has Stephane really re-reviewed this new version already?
And please Cc: everyone involved in the previous patch discussion, too.
Thanks, Daniel
> ---
> 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 | 1 +
> drivers/gpu/drm/udl/udl_drv.h | 3 +++
> drivers/gpu/drm/udl/udl_fb.c | 2 +-
> drivers/gpu/drm/udl/udl_main.c | 15 +++++++++++++++
> include/drm/drmP.h | 14 --------------
> 11 files changed, 21 insertions(+), 33 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..3cbafe7 100644
> --- a/drivers/gpu/drm/udl/udl_drv.c
> +++ b/drivers/gpu/drm/udl/udl_drv.c
> @@ -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..61e117a 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 including overhead */
> atomic_t cpu_kcycles_used; /* transpired during pixel processing */
> + atomic_t unplugged; /* device has been unplugged or gone away */
> };
>
> struct udl_gem_object {
> @@ -140,6 +141,8 @@ 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_main.c b/drivers/gpu/drm/udl/udl_main.c
> index 33dbfb2..f6028a4 100644
> --- a/drivers/gpu/drm/udl/udl_main.c
> +++ b/drivers/gpu/drm/udl/udl_main.c
> @@ -350,3 +350,18 @@ int udl_driver_unload(struct drm_device *dev)
> kfree(udl);
> return 0;
> }
> +
> +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 dev is dead */
> struct inode *anon_inode; /**< inode for private
> address-space */
> char *unique; /**< unique name of the device
> */
> /*@} */
> @@ -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
>
> _______________________________________________
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> dri-devel at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
