On Thu, Dec 01, 2016 at 01:44:16PM +0530, swati.dhingra@xxxxxxxxx wrote:
> From: Swati Dhingra <swati.dhingra@xxxxxxxxx>
>
> During drm module initialization, drm_core_init initializes the drmfs
> filesystem and register this with kernel. A driver specific directory is created
> inside drmfs root, and dentry of this directory is saved for subsequent use
> by the driver (e.g. i915). The driver can then create files/directories inside
> this root directory directly.
> In case of i915 driver, the top directory is created at '/sys/kernel/drm/i915'.
>
> Signed-off-by: Sourab Gupta <sourab.gupta@xxxxxxxxx>
> Signed-off-by: Swati Dhingra <swati.dhingra@xxxxxxxxx>
> ---
> drivers/gpu/drm/drm_drv.c | 22 ++++++++++++++++++++++
> include/drm/drm_drv.h | 3 +++
> 2 files changed, 25 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
> index 84fcfcb..ead360bd 100644
> --- a/drivers/gpu/drm/drm_drv.c
> +++ b/drivers/gpu/drm/drm_drv.c
> @@ -688,6 +688,14 @@ int drm_dev_register(struct drm_device *dev, unsigned long flags)
> {
> int ret;
>
> +#ifdef CONFIG_DRMFS
> + dev->driver->drmfs_root = drmfs_create_dir(dev->driver->name, NULL);
> + if (IS_ERR(dev->driver->drmfs_root)) {
> + DRM_ERROR("Failed to get drmfs root dentry\n");
> + return PTR_ERR(dev->driver->drmfs_root);
> + }
> +#endif
Don't do #ifdef in the code, instead provide dummy static inline functions
that do nothing in headers when a feature is disabled. For an example see
CONFIG_DRM_FBDEV_EMULATION in drm_fb_helper.[hc].
Also, drmfs here is seriously lacking documentation. E.g. where are we
supposed to put different things related to rendering, modesetting, and
all these issues? You need to add a section in drm-uabi.rst, write
kernel-doc + overview sections for all of this and pull it in.
-Daniel
> +
> mutex_lock(&drm_global_mutex);
>
> ret = drm_minor_register(dev, DRM_MINOR_CONTROL);
> @@ -758,6 +766,9 @@ void drm_dev_unregister(struct drm_device *dev)
> drm_minor_unregister(dev, DRM_MINOR_PRIMARY);
> drm_minor_unregister(dev, DRM_MINOR_RENDER);
> drm_minor_unregister(dev, DRM_MINOR_CONTROL);
> +#ifdef CONFIG_DRMFS
> + drmfs_remove(dev->driver->drmfs_root);
> +#endif
> }
> EXPORT_SYMBOL(drm_dev_unregister);
>
> @@ -825,6 +836,9 @@ static void drm_core_exit(void)
> {
> unregister_chrdev(DRM_MAJOR, "drm");
> debugfs_remove(drm_debugfs_root);
> +#ifdef CONFIG_DRMFS
> + drmfs_fini();
> +#endif
> drm_sysfs_destroy();
> idr_destroy(&drm_minors_idr);
> drm_connector_ida_destroy();
> @@ -845,6 +859,14 @@ static int __init drm_core_init(void)
> goto error;
> }
>
> +#ifdef CONFIG_DRMFS
> + ret = drmfs_init();
> + if (ret < 0) {
> + DRM_ERROR("Cannot create DRM FS: %d\n", ret);
> + goto error;
> + }
> +#endif
> +
> drm_debugfs_root = debugfs_create_dir("dri", NULL);
> if (!drm_debugfs_root) {
> ret = -ENOMEM;
> diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h
> index aad8bba..34804de 100644
> --- a/include/drm/drm_drv.h
> +++ b/include/drm/drm_drv.h
> @@ -403,6 +403,9 @@ struct drm_driver {
>
> /* List of devices hanging off this driver with stealth attach. */
> struct list_head legacy_dev_list;
> +
> + /* drmfs parent directory dentry for this driver */
> + struct dentry *drmfs_root;
> };
>
> extern __printf(6, 7)
> --
> 2.7.4
>
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> Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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