Clarify the relation between drm_fb_helper_fbdev_setup/teardown. Clarify
requirements for the new generic fbdev emulation API and log some more
details in case the driver does something wrong. Fix related typos.
Cc: Noralf Trønnes <noralf@xxxxxxxxxxx>
Signed-off-by: Peter Wu <peter@xxxxxxxxxxxxx>
---
drivers/gpu/drm/drm_fb_helper.c | 25 +++++++++++++++++++------
1 file changed, 19 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 4b0dd20bccb8..7f92ff173986 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -2821,7 +2821,9 @@ EXPORT_SYMBOL(drm_fb_helper_hotplug_event);
* The caller must to provide a &drm_fb_helper_funcs->fb_probe callback
* function.
*
- * See also: drm_fb_helper_initial_config()
+ * Use drm_fb_helper_fbdev_teardown() to destroy the fbdev.
+ *
+ * See also: drm_fb_helper_initial_config(), drm_fbdev_generic_setup().
*
* Returns:
* Zero on success or negative error code on failure.
@@ -3037,7 +3039,7 @@ static struct fb_deferred_io drm_fbdev_defio = {
* @fb_helper: fbdev helper structure
* @sizes: describes fbdev size and scanout surface size
*
- * This function uses the client API to crate a framebuffer backed by a dumb buffer.
+ * This function uses the client API to create a framebuffer backed by a dumb buffer.
*
* The _sys_ versions are used for &fb_ops.fb_read, fb_write, fb_fillrect,
* fb_copyarea, fb_imageblit.
@@ -3165,8 +3167,10 @@ static int drm_fbdev_client_hotplug(struct drm_client_dev *client)
if (dev->fb_helper)
return drm_fb_helper_hotplug_event(dev->fb_helper);
- if (!dev->mode_config.num_connector)
+ if (!dev->mode_config.num_connector) {
+ DRM_DEV_DEBUG(dev->dev, "No connectors found, will not create framebuffer!\n");
return 0;
+ }
ret = drm_fb_helper_fbdev_setup(dev, fb_helper, &drm_fb_helper_generic_funcs,
fb_helper->preferred_bpp, 0);
@@ -3187,13 +3191,15 @@ static const struct drm_client_funcs drm_fbdev_client_funcs = {
};
/**
- * drm_fb_helper_generic_fbdev_setup() - Setup generic fbdev emulation
+ * drm_fbdev_generic_setup() - Setup generic fbdev emulation
* @dev: DRM device
* @preferred_bpp: Preferred bits per pixel for the device.
* @dev->mode_config.preferred_depth is used if this is zero.
*
* This function sets up generic fbdev emulation for drivers that supports
- * dumb buffers with a virtual address and that can be mmap'ed.
+ * dumb buffers with a virtual address and that can be mmap'ed. If the driver
+ * does not support these functions, it could use drm_fb_helper_fbdev_setup().
+ * This function can only be used with devices created using drm_dev_register().
*
* Restore, hotplug events and teardown are all taken care of. Drivers that do
* suspend/resume need to call drm_fb_helper_set_suspend_unlocked() themselves.
@@ -3206,6 +3212,8 @@ static const struct drm_client_funcs drm_fbdev_client_funcs = {
* This function is safe to call even when there are no connectors present.
* Setup will be retried on the next hotplug event.
*
+ * The fbdev is destroyed by drm_dev_unregister().
+ *
* Returns:
* Zero on success or negative error code on failure.
*/
@@ -3214,6 +3222,8 @@ int drm_fbdev_generic_setup(struct drm_device *dev, unsigned int preferred_bpp)
struct drm_fb_helper *fb_helper;
int ret;
+ WARN(dev->fb_helper, "fb_helper is already set!\n");
+
if (!drm_fbdev_emulation)
return 0;
@@ -3224,12 +3234,15 @@ int drm_fbdev_generic_setup(struct drm_device *dev, unsigned int preferred_bpp)
ret = drm_client_new(dev, &fb_helper->client, "fbdev", &drm_fbdev_client_funcs);
if (ret) {
kfree(fb_helper);
+ DRM_DEV_ERROR(dev->dev, "Failed to register client: %d\n", ret);
return ret;
}
fb_helper->preferred_bpp = preferred_bpp;
- drm_fbdev_client_hotplug(&fb_helper->client);
+ ret = drm_fbdev_client_hotplug(&fb_helper->client);
+ if (ret)
+ DRM_DEV_DEBUG(dev->dev, "client hotplug ret=%d\n", ret);
return 0;
}
--
2.18.0
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