DRM: add mode setting support
Add mode setting support to the DRM layer.
This is a fairly big chunk of work that allows DRM drivers to provide
full output control and configuration capabilities to userspace. It was
motivated by several factors:
- the fb layer's APIs aren't suited for anything but simple
configurations
- coordination between the fb layer, DRM layer, and various userspace
drivers is poor to non-existent (radeonfb excepted)
- user level mode setting drivers makes displaying panic & oops
messages more difficult
- suspend/resume of graphics state is possible in many more
configurations with kernel level support
This commit just adds the core DRM part of the mode setting APIs.
Driver specific commits using these new structure and APIs will follow.
Co-authors: Jesse Barnes <jbarnes@virtuousgeek.org>, Jakob Bornecrantz <jakob@tungstengraphics.com>
Contributors: Alan Hourihane <alanh@tungstengraphics.com>, Maarten Maathuis <madman2003@gmail.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
index 1e787f8..1608f8d 100644
--- a/drivers/gpu/drm/drm_irq.c
+++ b/drivers/gpu/drm/drm_irq.c
@@ -305,6 +305,8 @@
case DRM_INST_HANDLER:
if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
return 0;
+ if (drm_core_check_feature(dev, DRIVER_MODESET))
+ return 0;
if (dev->if_version < DRM_IF_VERSION(1, 2) &&
ctl->irq != dev->pdev->irq)
return -EINVAL;
@@ -312,6 +314,8 @@
case DRM_UNINST_HANDLER:
if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
return 0;
+ if (drm_core_check_feature(dev, DRIVER_MODESET))
+ return 0;
return drm_irq_uninstall(dev);
default:
return -EINVAL;
@@ -427,6 +431,45 @@
EXPORT_SYMBOL(drm_vblank_put);
/**
+ * drm_vblank_pre_modeset - account for vblanks across mode sets
+ * @dev: DRM device
+ * @crtc: CRTC in question
+ * @post: post or pre mode set?
+ *
+ * Account for vblank events across mode setting events, which will likely
+ * reset the hardware frame counter.
+ */
+void drm_vblank_pre_modeset(struct drm_device *dev, int crtc)
+{
+ /*
+ * To avoid all the problems that might happen if interrupts
+ * were enabled/disabled around or between these calls, we just
+ * have the kernel take a reference on the CRTC (just once though
+ * to avoid corrupting the count if multiple, mismatch calls occur),
+ * so that interrupts remain enabled in the interim.
+ */
+ if (!dev->vblank_inmodeset[crtc]) {
+ dev->vblank_inmodeset[crtc] = 1;
+ drm_vblank_get(dev, crtc);
+ }
+}
+EXPORT_SYMBOL(drm_vblank_pre_modeset);
+
+void drm_vblank_post_modeset(struct drm_device *dev, int crtc)
+{
+ unsigned long irqflags;
+
+ if (dev->vblank_inmodeset[crtc]) {
+ spin_lock_irqsave(&dev->vbl_lock, irqflags);
+ dev->vblank_disable_allowed = 1;
+ dev->vblank_inmodeset[crtc] = 0;
+ spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
+ drm_vblank_put(dev, crtc);
+ }
+}
+EXPORT_SYMBOL(drm_vblank_post_modeset);
+
+/**
* drm_modeset_ctl - handle vblank event counter changes across mode switch
* @DRM_IOCTL_ARGS: standard ioctl arguments
*
@@ -441,7 +484,6 @@
struct drm_file *file_priv)
{
struct drm_modeset_ctl *modeset = data;
- unsigned long irqflags;
int crtc, ret = 0;
/* If drm_vblank_init() hasn't been called yet, just no-op */
@@ -454,28 +496,12 @@
goto out;
}
- /*
- * To avoid all the problems that might happen if interrupts
- * were enabled/disabled around or between these calls, we just
- * have the kernel take a reference on the CRTC (just once though
- * to avoid corrupting the count if multiple, mismatch calls occur),
- * so that interrupts remain enabled in the interim.
- */
switch (modeset->cmd) {
case _DRM_PRE_MODESET:
- if (!dev->vblank_inmodeset[crtc]) {
- dev->vblank_inmodeset[crtc] = 1;
- drm_vblank_get(dev, crtc);
- }
+ drm_vblank_pre_modeset(dev, crtc);
break;
case _DRM_POST_MODESET:
- if (dev->vblank_inmodeset[crtc]) {
- spin_lock_irqsave(&dev->vbl_lock, irqflags);
- dev->vblank_disable_allowed = 1;
- dev->vblank_inmodeset[crtc] = 0;
- spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
- drm_vblank_put(dev, crtc);
- }
+ drm_vblank_post_modeset(dev, crtc);
break;
default:
ret = -EINVAL;
