Implement legacy framebuffer ioctl FBIO_WAITFORVSYNC in the generic
framebuffer emulation driver. Legacy framebuffer users like non kms/drm
based OpenGL(ES)/EGL implementations may require the ioctl to
synchronize drawing or buffer flip for double buffering. It is tested on
the i.MX6.
Signed-off-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>
Tested-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
---
drivers/gpu/drm/drm_fb_helper.c | 68 ++++++++++++++++++++++++++++++++++-
include/drm/drm_fb_helper.h | 12 +++++-
2 files changed, 79 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index c6de87abaca8..8ac8716c023a 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -1240,6 +1240,74 @@ int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info)
EXPORT_SYMBOL(drm_fb_helper_setcmap);
/**
+ * drm_fb_helper_ioctl - legacy ioctl implementation
+ * @info: fbdev registered by the helper
+ * @cmd: ioctl command
+ * @arg: ioctl argument
+ *
+ * A helper to implement the standard fbdev ioctl. Only
+ * FBIO_WAITFORVSYNC is implemented for now.
+ */
+int drm_fb_helper_ioctl(struct fb_info *info, unsigned int cmd,
+ unsigned long arg)
+{
+ struct drm_fb_helper *fb_helper = info->par;
+ struct drm_device *dev = fb_helper->dev;
+ struct drm_mode_set *mode_set;
+ struct drm_crtc *crtc;
+ int ret = 0;
+
+ mutex_lock(&dev->mode_config.mutex);
+ if (!drm_fb_helper_is_bound(fb_helper)) {
+ ret = -EBUSY;
+ goto unlock;
+ }
+
+ switch (cmd) {
+ case FBIO_WAITFORVSYNC:
+ /*
+ * Only consider the first CRTC.
+ *
+ * This ioctl is supposed to take the CRTC number as
+ * an argument, but in fbdev times, what that number
+ * was supposed to be was quite unclear, different
+ * drivers were passing that argument differently
+ * (some by reference, some by value), and most of the
+ * userspace applications were just hardcoding 0 as an
+ * argument.
+ *
+ * The first CRTC should be the integrated panel on
+ * most drivers, so this is the best choice we can
+ * make. If we're not smart enough here, one should
+ * just consider switch the userspace to KMS.
+ */
+ mode_set = &fb_helper->crtc_info[0].mode_set;
+ crtc = mode_set->crtc;
+
+ /*
+ * Only wait for a vblank event if the CRTC is
+ * enabled, otherwise just don't do anythintg,
+ * not even report an error.
+ */
+ ret = drm_crtc_vblank_get(crtc);
+ if (!ret) {
+ drm_crtc_wait_one_vblank(crtc);
+ drm_crtc_vblank_put(crtc);
+ }
+
+ ret = 0;
+ goto unlock;
+ default:
+ ret = -ENOTTY;
+ }
+
+unlock:
+ mutex_unlock(&dev->mode_config.mutex);
+ return ret;
+}
+EXPORT_SYMBOL(drm_fb_helper_ioctl);
+
+/**
* drm_fb_helper_check_var - implementation for ->fb_check_var
* @var: screeninfo to check
* @info: fbdev registered by the helper
diff --git a/include/drm/drm_fb_helper.h b/include/drm/drm_fb_helper.h
index 975deedd593e..2891888c6e41 100644
--- a/include/drm/drm_fb_helper.h
+++ b/include/drm/drm_fb_helper.h
@@ -230,7 +230,8 @@ struct drm_fb_helper {
.fb_blank = drm_fb_helper_blank, \
.fb_pan_display = drm_fb_helper_pan_display, \
.fb_debug_enter = drm_fb_helper_debug_enter, \
- .fb_debug_leave = drm_fb_helper_debug_leave
+ .fb_debug_leave = drm_fb_helper_debug_leave, \
+ .fb_ioctl = drm_fb_helper_ioctl
#ifdef CONFIG_DRM_FBDEV_EMULATION
void drm_fb_helper_prepare(struct drm_device *dev, struct drm_fb_helper *helper,
@@ -286,6 +287,9 @@ void drm_fb_helper_set_suspend_unlocked(struct drm_fb_helper *fb_helper,
int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info);
+int drm_fb_helper_ioctl(struct fb_info *info, unsigned int cmd,
+ unsigned long arg);
+
int drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper);
int drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper, int bpp_sel);
int drm_fb_helper_single_add_all_connectors(struct drm_fb_helper *fb_helper);
@@ -377,6 +381,12 @@ static inline int drm_fb_helper_setcmap(struct fb_cmap *cmap,
return 0;
}
+static inline int drm_fb_helper_ioctl(struct fb_info *info, unsigned int cmd,
+ unsigned long arg)
+{
+ return 0;
+}
+
static inline void drm_fb_helper_unlink_fbi(struct drm_fb_helper *fb_helper)
{
}
--
git-series 0.8.11
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