Den 14.12.2017 21.19, skrev Daniel Vetter:
On Thu, Dec 14, 2017 at 08:10:03PM +0100, Noralf Trønnes wrote:
Add helpers to setup and teardown fbdev emulation.
Signed-off-by: Noralf Trønnes <nor...@tronnes.org>
---
drivers/gpu/drm/drm_fb_helper.c | 106 ++++++++++++++++++++++++++++++++++++++++
include/drm/drm_fb_helper.h | 25 ++++++++++
2 files changed, 131 insertions(+)
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 04a3a5ce370a..823fc8f50d85 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -2729,6 +2729,112 @@ int drm_fb_helper_hotplug_event(struct drm_fb_helper
*fb_helper)
}
EXPORT_SYMBOL(drm_fb_helper_hotplug_event);
+/**
+ * drm_fb_helper_fbdev_setup() - Setup fbdev emulation
+ * @dev: DRM device
+ * @fb_helper: fbdev helper structure to set up
+ * @funcs: fbdev helper functions
+ * @preferred_bpp: Preferred bits per pixel for the device.
+ * @dev->mode_config.preferred_depth is used if this is zero.
+ * @max_conn_count: Maximum number of connectors.
+ * @dev->mode_config.num_connector is used if this is zero.
+ *
+ * This function sets up fbdev emulation and registers fbdev for access by
+ * userspace. If all connectors are disconnected, setup is deferred to the next
+ * time drm_fb_helper_hotplug_event() is called.
+ * The caller must to provide a &drm_fb_helper_funcs->fb_probe callback
+ * function.
I think we should be a bit clearer when it's not advisable to use this
helper because there are issues:
- when connectors can be hotplugged (e.g. dp mst). For that case you need
to init the fbdev before you enabling hotplugging, but call
initial_config after you've enabled hotplugging. Otherwise there's a
posssible race window.
I have made a propose DOC change in patch 4.
- when there's anything else that mus be done before we do the fbdev
registration, e.g. defio_init.
This happens in .fb_probe callback. See my reply to patch 5.
So still not 100% sure this will help you all that much, but it's also not
an unreasonable idea.
Assuming we can agree on the ceveats and how do document them:
Reviewed-by: Daniel Vetter <daniel.vet...@ffwll.ch>
+ *
+ * See also: drm_fb_helper_initial_config()
+ *
+ * Returns:
+ * Zero on success or negative error code on failure.
+ */
+int drm_fb_helper_fbdev_setup(struct drm_device *dev,
+ struct drm_fb_helper *fb_helper,
+ const struct drm_fb_helper_funcs *funcs,
+ unsigned int preferred_bpp,
+ unsigned int max_conn_count)
+{
+ int ret;
+
+ if (!preferred_bpp)
+ preferred_bpp = dev->mode_config.preferred_depth;
+ if (!preferred_bpp)
+ preferred_bpp = 32;
+
+ if (!max_conn_count)
+ max_conn_count = dev->mode_config.num_connector;
+ if (!max_conn_count) {
+ DRM_DEV_ERROR(dev->dev, "No connectors\n");
+ return -EINVAL;
+ }
+
+ drm_fb_helper_prepare(dev, fb_helper, funcs);
+
+ ret = drm_fb_helper_init(dev, fb_helper, max_conn_count);
+ if (ret < 0) {
+ DRM_DEV_ERROR(dev->dev, "Failed to initialize fbdev helper\n");
+ return ret;
+ }
+
+ ret = drm_fb_helper_single_add_all_connectors(fb_helper);
+ if (ret < 0) {
+ DRM_DEV_ERROR(dev->dev, "Failed to add connectors\n");
+ goto err_drm_fb_helper_fini;
+ }
+
+ if (!drm_drv_uses_atomic_modeset(dev))
+ drm_helper_disable_unused_functions(dev);
+
+ ret = drm_fb_helper_initial_config(fb_helper, preferred_bpp);
+ if (ret < 0) {
+ DRM_DEV_ERROR(dev->dev, "Failed to set fbdev configuration\n");
+ goto err_drm_fb_helper_fini;
+ }
+
+ return 0;
+
+err_drm_fb_helper_fini:
+ drm_fb_helper_fini(fb_helper);
+
+ return ret;
+}
+EXPORT_SYMBOL(drm_fb_helper_fbdev_setup);
+
+/**
+ * drm_fb_helper_fbdev_teardown - Tear down fbdev emulation
+ * @dev: DRM device
+ *
+ * This function unregisters fbdev if not already done and cleans up the
+ * associated resources including the &drm_framebuffer.
+ * The driver is responsible for freeing the &drm_fb_helper structure which is
+ * stored in &drm_device->fb_helper. Do note that this pointer has been cleared
+ * when this function returns.
+ *
+ * In order to support device removal/unplug while file handles are still open,
+ * drm_fb_helper_unregister_fbi() should be called on device removal and
+ * drm_fb_helper_fbdev_teardown() in the &drm_driver->release callback when
+ * file handles are closed.
+ */
+void drm_fb_helper_fbdev_teardown(struct drm_device *dev)
+{
+ struct drm_fb_helper *fb_helper = dev->fb_helper;
+
+ if (!fb_helper)
+ return;
+
+ /* Unregister if it hasn't been done already */
+ if (fb_helper->fbdev && fb_helper->fbdev->dev)
+ drm_fb_helper_unregister_fbi(fb_helper);
+
+ drm_fb_helper_fini(fb_helper);
+
+ if (fb_helper->fb)
+ drm_framebuffer_remove(fb_helper->fb);
+}
+EXPORT_SYMBOL(drm_fb_helper_fbdev_teardown);
+
/**
* drm_fb_helper_lastclose - DRM driver lastclose helper for fbdev emulation
* @dev: DRM device
diff --git a/include/drm/drm_fb_helper.h b/include/drm/drm_fb_helper.h
index 1bd624579db7..aa78ac3b8ad0 100644
--- a/include/drm/drm_fb_helper.h
+++ b/include/drm/drm_fb_helper.h
@@ -320,6 +320,13 @@ int drm_fb_helper_add_one_connector(struct drm_fb_helper
*fb_helper, struct drm_
int drm_fb_helper_remove_one_connector(struct drm_fb_helper *fb_helper,
struct drm_connector *connector);
+int drm_fb_helper_fbdev_setup(struct drm_device *dev,
+ struct drm_fb_helper *fb_helper,
+ const struct drm_fb_helper_funcs *funcs,
+ unsigned int preferred_bpp,
+ unsigned int max_conn_count);
+void drm_fb_helper_fbdev_teardown(struct drm_device *dev);
+
void drm_fb_helper_lastclose(struct drm_device *dev);
void drm_fb_helper_output_poll_changed(struct drm_device *dev);
#else
@@ -525,6 +532,24 @@ drm_fb_helper_remove_one_connector(struct drm_fb_helper
*fb_helper,
return 0;
}
+static inline int
+drm_fb_helper_fbdev_setup(struct drm_device *dev,
+ struct drm_fb_helper *fb_helper,
+ const struct drm_fb_helper_funcs *funcs,
+ unsigned int preferred_bpp,
+ unsigned int max_conn_count)
+{
+ /* So drivers can use it to free the struct */
+ dev->fb_helper = fb_helper;
+
+ return 0;
+}
+
+static inline void drm_fb_helper_fbdev_teardown(struct drm_device *dev)
+{
+ dev->fb_helper = NULL;
+}
+
static inline void drm_fb_helper_lastclose(struct drm_device *dev)
{
}
--
2.14.2
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