[PATCH v3 3/3] drm: simpledrm: honour remove_conflicting_framebuffers()

Noralf Trønnes
2016-08-14T16:52:27Z

There is currently no non-fbdev mechanism in place to kick out
simpledrm when the real hw-driver is probed. As a stop gap until
that is in place, honour remove_conflicting_framebuffers() and
delete the simple-framebuffer platform device when it's called.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
---

Changes from version 2:
- Don't forget to free fb_info when kicked out.

drivers/gpu/drm/simpledrm/Kconfig | 5 +++
drivers/gpu/drm/simpledrm/Makefile | 2 +-
drivers/gpu/drm/simpledrm/simpledrm.h | 11 +++++-
drivers/gpu/drm/simpledrm/simpledrm_drv.c | 3 ++
drivers/gpu/drm/simpledrm/simpledrm_fbdev.c | 55 +++++++++++++++++++++++++++--
5 files changed, 72 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/simpledrm/Kconfig b/drivers/gpu/drm/simpledrm/Kconfig
index 9454536..6205b17 100644
--- a/drivers/gpu/drm/simpledrm/Kconfig
+++ b/drivers/gpu/drm/simpledrm/Kconfig
@@ -16,6 +16,11 @@ config DRM_SIMPLEDRM
If fbdev support is enabled, this driver will also provide an fbdev
compatibility layer.

+ WARNING
+ fbdev must be enabled for simpledrm to disable itself when a real
+ hw-driver is probed. It relies on remove_conflicting_framebuffers()
+ to be called by the hw-driver.
+
If unsure, say Y.

To compile this driver as a module, choose M here: the
diff --git a/drivers/gpu/drm/simpledrm/Makefile b/drivers/gpu/drm/simpledrm/Makefile
index 7087245..4b4bcdd 100644
--- a/drivers/gpu/drm/simpledrm/Makefile
+++ b/drivers/gpu/drm/simpledrm/Makefile
@@ -1,5 +1,5 @@
simpledrm-y := simpledrm_drv.o simpledrm_kms.o simpledrm_gem.o \
simpledrm_damage.o
-simpledrm-$(CONFIG_DRM_FBDEV_EMULATION) += simpledrm_fbdev.o
+simpledrm-$(CONFIG_FB) += simpledrm_fbdev.o

obj-$(CONFIG_DRM_SIMPLEDRM) := simpledrm.o
diff --git a/drivers/gpu/drm/simpledrm/simpledrm.h b/drivers/gpu/drm/simpledrm/simpledrm.h
index f01b75d..7bc1292 100644
--- a/drivers/gpu/drm/simpledrm/simpledrm.h
+++ b/drivers/gpu/drm/simpledrm/simpledrm.h
@@ -88,13 +88,15 @@ struct sdrm_framebuffer {

#define to_sdrm_fb(x) container_of(x, struct sdrm_framebuffer, base)

-#ifdef CONFIG_DRM_FBDEV_EMULATION
+#ifdef CONFIG_FB

void sdrm_fbdev_init(struct sdrm_device *sdrm);
void sdrm_fbdev_cleanup(struct sdrm_device *sdrm);
void sdrm_fbdev_display_pipe_update(struct sdrm_device *sdrm,
struct drm_framebuffer *fb);
void sdrm_fbdev_restore_mode(struct sdrm_device *sdrm);
+void sdrm_fbdev_kickout_init(void);
+void sdrm_fbdev_kickout_exit(void);

#else

@@ -115,6 +117,13 @@ static inline void sdrm_fbdev_restore_mode(struct sdrm_device *sdrm)
{
}

+static inline void sdrm_fbdev_kickout_init(void)
+{
+}
+
+static inline void sdrm_fbdev_kickout_exit(void)
+{
+}
#endif

#endif /* SDRM_DRV_H */
diff --git a/drivers/gpu/drm/simpledrm/simpledrm_drv.c b/drivers/gpu/drm/simpledrm/simpledrm_drv.c
index a4e6566..26956c3 100644
--- a/drivers/gpu/drm/simpledrm/simpledrm_drv.c
+++ b/drivers/gpu/drm/simpledrm/simpledrm_drv.c
@@ -527,12 +527,15 @@ static int __init sdrm_init(void)
}
}

+ sdrm_fbdev_kickout_init();
+
return 0;
}
module_init(sdrm_init);

static void __exit sdrm_exit(void)
{
+ sdrm_fbdev_kickout_exit();
platform_driver_unregister(&sdrm_simplefb_driver);
}
module_exit(sdrm_exit);
diff --git a/drivers/gpu/drm/simpledrm/simpledrm_fbdev.c b/drivers/gpu/drm/simpledrm/simpledrm_fbdev.c
index 4038dd9..daf5943 100644
--- a/drivers/gpu/drm/simpledrm/simpledrm_fbdev.c
+++ b/drivers/gpu/drm/simpledrm/simpledrm_fbdev.c
@@ -28,6 +28,16 @@ static inline struct sdrm_fbdev *to_sdrm_fbdev(struct drm_fb_helper *helper)
return container_of(helper, struct sdrm_fbdev, fb_helper);
}

+/*
+ * Releasing has to be done outside the notifier callchain when we're
+ * kicked out, since do_unregister_framebuffer() calls put_fb_info()
+ * after the notifier has run.
+ */
+static void sdrm_fbdev_fb_destroy(struct fb_info *info)
+{
+ drm_fb_helper_release_fbi(info->par);
+}
+
static struct fb_ops sdrm_fbdev_ops = {
.owner = THIS_MODULE,
.fb_fillrect = drm_fb_helper_cfb_fillrect,
@@ -36,6 +46,7 @@ static struct fb_ops sdrm_fbdev_ops = {
.fb_check_var = drm_fb_helper_check_var,
.fb_set_par = drm_fb_helper_set_par,
.fb_setcmap = drm_fb_helper_setcmap,
+ .fb_destroy = sdrm_fbdev_fb_destroy,
};

static struct drm_framebuffer_funcs sdrm_fb_funcs = {
@@ -85,6 +96,9 @@ static int sdrm_fbdev_create(struct drm_fb_helper *helper,
fbi->fix.smem_len = sdrm->fb_size;
fbi->screen_base = sdrm->fb_map;

+ fbi->apertures->ranges[0].base = sdrm->fb_base;
+ fbi->apertures->ranges[0].size = sdrm->fb_size;
+
return 0;

err_fb_info_destroy:
@@ -154,8 +168,11 @@ void sdrm_fbdev_cleanup(struct sdrm_device *sdrm)
sdrm->fbdev = NULL;
fb_helper = &fbdev->fb_helper;

- drm_fb_helper_unregister_fbi(fb_helper);
- drm_fb_helper_release_fbi(fb_helper);
+ /* it might have been kicked out */
+ if (registered_fb[fbdev->fb_helper.fbdev->node])
+ drm_fb_helper_unregister_fbi(fb_helper);
+
+ /* freeing fb_info is done in fb_ops.fb_destroy() */

drm_framebuffer_unregister_private(&fbdev->fb);
drm_framebuffer_cleanup(&fbdev->fb);
@@ -199,3 +216,37 @@ void sdrm_fbdev_restore_mode(struct sdrm_device *sdrm)
if (fbdev->fb_helper.fbdev->state != FBINFO_STATE_RUNNING)
sdrm_fbdev_set_suspend(fbdev->fb_helper.fbdev, 0);
}
+
+static int sdrm_fbdev_event_notify(struct notifier_block *self,
+ unsigned long action, void *data)
+{
+ struct sdrm_device *sdrm;
+ struct fb_event *event = data;
+ struct fb_info *info = event->info;
+ struct drm_fb_helper *fb_helper = info->par;
+
+ if (action != FB_EVENT_FB_UNREGISTERED || !fb_helper ||
+ !fb_helper->dev || fb_helper->fbdev != info)
+ return NOTIFY_DONE;
+
+ sdrm = fb_helper->dev->dev_private;
+
+ if (sdrm && sdrm->fbdev)
+ platform_device_del(sdrm->ddev->platformdev);
+
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block sdrm_fbdev_event_notifier = {
+ .notifier_call = sdrm_fbdev_event_notify,
+};
+
+void sdrm_fbdev_kickout_init(void)
+{
+ fb_register_client(&sdrm_fbdev_event_notifier);
+}
+
+void sdrm_fbdev_kickout_exit(void)
+{
+ fb_unregister_client(&sdrm_fbdev_event_notifier);
+}
--
2.8.2