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authorMaxime Ripard <maxime.ripard@free-electrons.com>2017-02-28 18:36:51 +0300
committerDaniel Vetter <daniel.vetter@ffwll.ch>2017-03-02 10:12:15 +0300
commit0f3bbe074dd179dfbdaabcc601086bc4f6ab885b (patch)
tree16e8bfb3bac288170abacfebf2827e1d45c3d0de /drivers/gpu/drm
parent35f5022fbe9b05ea7ab479f299dc1b63b0ceb8c6 (diff)
downloadlinux-0f3bbe074dd179dfbdaabcc601086bc4f6ab885b.tar.xz
drm/fb-helper: implement ioctl FBIO_WAITFORVSYNC
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@free-electrons.com> Tested-by: Neil Armstrong <narmstrong@baylibre.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Diffstat (limited to 'drivers/gpu/drm')
-rw-r--r--drivers/gpu/drm/drm_fb_helper.c68
1 files changed, 68 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 2c92ccf5266a..45fde2ffef2a 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -1245,6 +1245,74 @@ 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_ops.fb_check_var
* @var: screeninfo to check
* @info: fbdev registered by the helper