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path: root/drivers/gpu/drm/drm_fb_helper.c
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Diffstat (limited to 'drivers/gpu/drm/drm_fb_helper.c')
-rw-r--r--drivers/gpu/drm/drm_fb_helper.c115
1 files changed, 95 insertions, 20 deletions
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index d5d8cea1a679..3144db9dc0f1 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -49,10 +49,11 @@ static LIST_HEAD(kernel_fb_helper_list);
* helper functions used by many drivers to implement the kernel mode setting
* interfaces.
*
- * Initialization is done as a three-step process with drm_fb_helper_init(),
- * drm_fb_helper_single_add_all_connectors() and drm_fb_helper_initial_config().
- * Drivers with fancier requirements than the default behaviour can override the
- * second step with their own code. Teardown is done with drm_fb_helper_fini().
+ * Initialization is done as a four-step process with drm_fb_helper_prepare(),
+ * drm_fb_helper_init(), drm_fb_helper_single_add_all_connectors() and
+ * drm_fb_helper_initial_config(). Drivers with fancier requirements than the
+ * default behaviour can override the third step with their own code.
+ * Teardown is done with drm_fb_helper_fini().
*
* At runtime drivers should restore the fbdev console by calling
* drm_fb_helper_restore_fbdev_mode() from their ->lastclose callback. They
@@ -63,6 +64,19 @@ static LIST_HEAD(kernel_fb_helper_list);
*
* All other functions exported by the fb helper library can be used to
* implement the fbdev driver interface by the driver.
+ *
+ * It is possible, though perhaps somewhat tricky, to implement race-free
+ * hotplug detection using the fbdev helpers. The drm_fb_helper_prepare()
+ * helper must be called first to initialize the minimum required to make
+ * hotplug detection work. Drivers also need to make sure to properly set up
+ * the dev->mode_config.funcs member. After calling drm_kms_helper_poll_init()
+ * it is safe to enable interrupts and start processing hotplug events. At the
+ * same time, drivers should initialize all modeset objects such as CRTCs,
+ * encoders and connectors. To finish up the fbdev helper initialization, the
+ * drm_fb_helper_init() function is called. To probe for all attached displays
+ * and set up an initial configuration using the detected hardware, drivers
+ * should call drm_fb_helper_single_add_all_connectors() followed by
+ * drm_fb_helper_initial_config().
*/
/**
@@ -105,6 +119,58 @@ fail:
}
EXPORT_SYMBOL(drm_fb_helper_single_add_all_connectors);
+int drm_fb_helper_add_one_connector(struct drm_fb_helper *fb_helper, struct drm_connector *connector)
+{
+ struct drm_fb_helper_connector **temp;
+ struct drm_fb_helper_connector *fb_helper_connector;
+
+ WARN_ON(!mutex_is_locked(&fb_helper->dev->mode_config.mutex));
+ if (fb_helper->connector_count + 1 > fb_helper->connector_info_alloc_count) {
+ temp = krealloc(fb_helper->connector_info, sizeof(struct drm_fb_helper_connector) * (fb_helper->connector_count + 1), GFP_KERNEL);
+ if (!temp)
+ return -ENOMEM;
+
+ fb_helper->connector_info_alloc_count = fb_helper->connector_count + 1;
+ fb_helper->connector_info = temp;
+ }
+
+
+ fb_helper_connector = kzalloc(sizeof(struct drm_fb_helper_connector), GFP_KERNEL);
+ if (!fb_helper_connector)
+ return -ENOMEM;
+
+ fb_helper_connector->connector = connector;
+ fb_helper->connector_info[fb_helper->connector_count++] = fb_helper_connector;
+ return 0;
+}
+EXPORT_SYMBOL(drm_fb_helper_add_one_connector);
+
+int drm_fb_helper_remove_one_connector(struct drm_fb_helper *fb_helper,
+ struct drm_connector *connector)
+{
+ struct drm_fb_helper_connector *fb_helper_connector;
+ int i, j;
+
+ WARN_ON(!mutex_is_locked(&fb_helper->dev->mode_config.mutex));
+
+ for (i = 0; i < fb_helper->connector_count; i++) {
+ if (fb_helper->connector_info[i]->connector == connector)
+ break;
+ }
+
+ if (i == fb_helper->connector_count)
+ return -EINVAL;
+ fb_helper_connector = fb_helper->connector_info[i];
+
+ for (j = i + 1; j < fb_helper->connector_count; j++) {
+ fb_helper->connector_info[j - 1] = fb_helper->connector_info[j];
+ }
+ fb_helper->connector_count--;
+ kfree(fb_helper_connector);
+ return 0;
+}
+EXPORT_SYMBOL(drm_fb_helper_remove_one_connector);
+
static int drm_fb_helper_parse_command_line(struct drm_fb_helper *fb_helper)
{
struct drm_fb_helper_connector *fb_helper_conn;
@@ -199,9 +265,6 @@ int drm_fb_helper_debug_enter(struct fb_info *info)
struct drm_crtc_helper_funcs *funcs;
int i;
- if (list_empty(&kernel_fb_helper_list))
- return false;
-
list_for_each_entry(helper, &kernel_fb_helper_list, kernel_fb_list) {
for (i = 0; i < helper->crtc_count; i++) {
struct drm_mode_set *mode_set =
@@ -531,6 +594,24 @@ static void drm_fb_helper_crtc_free(struct drm_fb_helper *helper)
}
/**
+ * drm_fb_helper_prepare - setup a drm_fb_helper structure
+ * @dev: DRM device
+ * @helper: driver-allocated fbdev helper structure to set up
+ * @funcs: pointer to structure of functions associate with this helper
+ *
+ * Sets up the bare minimum to make the framebuffer helper usable. This is
+ * useful to implement race-free initialization of the polling helpers.
+ */
+void drm_fb_helper_prepare(struct drm_device *dev, struct drm_fb_helper *helper,
+ const struct drm_fb_helper_funcs *funcs)
+{
+ INIT_LIST_HEAD(&helper->kernel_fb_list);
+ helper->funcs = funcs;
+ helper->dev = dev;
+}
+EXPORT_SYMBOL(drm_fb_helper_prepare);
+
+/**
* drm_fb_helper_init - initialize a drm_fb_helper structure
* @dev: drm device
* @fb_helper: driver-allocated fbdev helper structure to initialize
@@ -542,8 +623,7 @@ static void drm_fb_helper_crtc_free(struct drm_fb_helper *helper)
* nor register the fbdev. This is only done in drm_fb_helper_initial_config()
* to allow driver writes more control over the exact init sequence.
*
- * Drivers must set fb_helper->funcs before calling
- * drm_fb_helper_initial_config().
+ * Drivers must call drm_fb_helper_prepare() before calling this function.
*
* RETURNS:
* Zero if everything went ok, nonzero otherwise.
@@ -558,10 +638,6 @@ int drm_fb_helper_init(struct drm_device *dev,
if (!max_conn_count)
return -EINVAL;
- fb_helper->dev = dev;
-
- INIT_LIST_HEAD(&fb_helper->kernel_fb_list);
-
fb_helper->crtc_info = kcalloc(crtc_count, sizeof(struct drm_fb_helper_crtc), GFP_KERNEL);
if (!fb_helper->crtc_info)
return -ENOMEM;
@@ -572,6 +648,7 @@ int drm_fb_helper_init(struct drm_device *dev,
kfree(fb_helper->crtc_info);
return -ENOMEM;
}
+ fb_helper->connector_info_alloc_count = dev->mode_config.num_connector;
fb_helper->connector_count = 0;
for (i = 0; i < crtc_count; i++) {
@@ -1056,7 +1133,6 @@ void drm_fb_helper_fill_fix(struct fb_info *info, uint32_t pitch,
info->fix.ypanstep = 1; /* doing it in hw */
info->fix.ywrapstep = 0;
info->fix.accel = FB_ACCEL_NONE;
- info->fix.type_aux = 0;
info->fix.line_length = pitch;
return;
@@ -1613,8 +1689,10 @@ EXPORT_SYMBOL(drm_fb_helper_initial_config);
* either the output polling work or a work item launched from the driver's
* hotplug interrupt).
*
- * Note that the driver must ensure that this is only called _after_ the fb has
- * been fully set up, i.e. after the call to drm_fb_helper_initial_config.
+ * Note that drivers may call this even before calling
+ * drm_fb_helper_initial_config but only aftert drm_fb_helper_init. This allows
+ * for a race-free fbcon setup and will make sure that the fbdev emulation will
+ * not miss any hotplug events.
*
* RETURNS:
* 0 on success and a non-zero error code otherwise.
@@ -1624,11 +1702,8 @@ int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper)
struct drm_device *dev = fb_helper->dev;
u32 max_width, max_height;
- if (!fb_helper->fb)
- return 0;
-
mutex_lock(&fb_helper->dev->mode_config.mutex);
- if (!drm_fb_helper_is_bound(fb_helper)) {
+ if (!fb_helper->fb || !drm_fb_helper_is_bound(fb_helper)) {
fb_helper->delayed_hotplug = true;
mutex_unlock(&fb_helper->dev->mode_config.mutex);
return 0;