drm/fb-helper: Add drm_fb_helper_set_suspend_unlocked()
This adds a function that also takes the console lock before calling
fb_set_suspend() in contrast to drm_fb_helper_set_suspend() which is
a plain wrapper around fb_set_suspend().
Resume is run asynchronously using a worker if the console lock is
already taken. This is modelled after the i915 driver.
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1471953246-29602-1-git-send-email-noralf@tronnes.org
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index c0d1066..43491a6 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -29,6 +29,7 @@
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/console.h>
#include <linux/kernel.h>
#include <linux/sysrq.h>
#include <linux/slab.h>
@@ -617,6 +618,16 @@
kfree(helper->crtc_info);
}
+static void drm_fb_helper_resume_worker(struct work_struct *work)
+{
+ struct drm_fb_helper *helper = container_of(work, struct drm_fb_helper,
+ resume_work);
+
+ console_lock();
+ fb_set_suspend(helper->fbdev, 0);
+ console_unlock();
+}
+
static void drm_fb_helper_dirty_work(struct work_struct *work)
{
struct drm_fb_helper *helper = container_of(work, struct drm_fb_helper,
@@ -648,6 +659,7 @@
{
INIT_LIST_HEAD(&helper->kernel_fb_list);
spin_lock_init(&helper->dirty_lock);
+ INIT_WORK(&helper->resume_work, drm_fb_helper_resume_worker);
INIT_WORK(&helper->dirty_work, drm_fb_helper_dirty_work);
helper->dirty_clip.x1 = helper->dirty_clip.y1 = ~0;
helper->funcs = funcs;
@@ -1025,7 +1037,9 @@
* @fb_helper: driver-allocated fbdev helper
* @state: desired state, zero to resume, non-zero to suspend
*
- * A wrapper around fb_set_suspend implemented by fbdev core
+ * A wrapper around fb_set_suspend implemented by fbdev core.
+ * Use drm_fb_helper_set_suspend_unlocked() if you don't need to take
+ * the lock yourself
*/
void drm_fb_helper_set_suspend(struct drm_fb_helper *fb_helper, int state)
{
@@ -1034,6 +1048,52 @@
}
EXPORT_SYMBOL(drm_fb_helper_set_suspend);
+/**
+ * drm_fb_helper_set_suspend_unlocked - wrapper around fb_set_suspend that also
+ * takes the console lock
+ * @fb_helper: driver-allocated fbdev helper
+ * @state: desired state, zero to resume, non-zero to suspend
+ *
+ * A wrapper around fb_set_suspend() that takes the console lock. If the lock
+ * isn't available on resume, a worker is tasked with waiting for the lock
+ * to become available. The console lock can be pretty contented on resume
+ * due to all the printk activity.
+ *
+ * This function can be called multiple times with the same state since
+ * &fb_info->state is checked to see if fbdev is running or not before locking.
+ *
+ * Use drm_fb_helper_set_suspend() if you need to take the lock yourself.
+ */
+void drm_fb_helper_set_suspend_unlocked(struct drm_fb_helper *fb_helper,
+ int suspend)
+{
+ if (!fb_helper || !fb_helper->fbdev)
+ return;
+
+ /* make sure there's no pending/ongoing resume */
+ flush_work(&fb_helper->resume_work);
+
+ if (suspend) {
+ if (fb_helper->fbdev->state != FBINFO_STATE_RUNNING)
+ return;
+
+ console_lock();
+
+ } else {
+ if (fb_helper->fbdev->state == FBINFO_STATE_RUNNING)
+ return;
+
+ if (!console_trylock()) {
+ schedule_work(&fb_helper->resume_work);
+ return;
+ }
+ }
+
+ fb_set_suspend(fb_helper->fbdev, suspend);
+ console_unlock();
+}
+EXPORT_SYMBOL(drm_fb_helper_set_suspend_unlocked);
+
static int setcolreg(struct drm_crtc *crtc, u16 red, u16 green,
u16 blue, u16 regno, struct fb_info *info)
{