On Wed, Jul 13, 2016 at 10:11:47AM +0200, Stefan Christ wrote: > 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. > > Code is based on > https://github.com/Xilinx/linux-xlnx/blob/master/drivers/gpu/drm/xilinx/xilinx_drm_fb.c#L196 > > Signed-off-by: Stefan Christ <s.christ@xxxxxxxxx> > --- > drivers/gpu/drm/drm_fb_cma_helper.c | 1 + > drivers/gpu/drm/drm_fb_helper.c | 43 +++++++++++++++++++++++++++++++++++++ > include/drm/drm_fb_helper.h | 2 ++ > 3 files changed, 46 insertions(+) > > diff --git a/drivers/gpu/drm/drm_fb_cma_helper.c b/drivers/gpu/drm/drm_fb_cma_helper.c > index be66042..95657da 100644 > --- a/drivers/gpu/drm/drm_fb_cma_helper.c > +++ b/drivers/gpu/drm/drm_fb_cma_helper.c > @@ -313,6 +313,7 @@ static struct fb_ops drm_fbdev_cma_ops = { > .fb_blank = drm_fb_helper_blank, > .fb_pan_display = drm_fb_helper_pan_display, > .fb_setcmap = drm_fb_helper_setcmap, > + .fb_ioctl = drm_fb_helper_ioctl, > }; > > static int drm_fbdev_cma_deferred_io_mmap(struct fb_info *info, > diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c > index 7c2eb75..4d1f9b9 100644 > --- a/drivers/gpu/drm/drm_fb_helper.c > +++ b/drivers/gpu/drm/drm_fb_helper.c > @@ -1167,6 +1167,49 @@ 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: > + * @cmd: ioctl like FBIO_WAITFORVSYNC > + * @arg: ioctl argument A bit more verbose kerneldoc would be great. Also, if you add this I think we should roll it out for all drivers, for consistency of the supported fbdev features when using emulation. -Daniel > + */ > +int drm_fb_helper_ioctl(struct fb_info *info, unsigned int cmd, unsigned long arg) > +{ > + struct drm_fb_helper *fb_helper = info->par; > + unsigned int i; > + int ret = 0; You must first check whether fbdev owns the kms driver by calling drm_fb_helper_is_bound(). Not sure whether the ioctl should fail, or whether you instead should msleep(16) to throttle userspace a bit. Up to you really. > + > + switch (cmd) { > + case FBIO_WAITFORVSYNC: > + for (i = 0; i < fb_helper->crtc_count; i++) { > + struct drm_mode_set *mode_set; > + struct drm_crtc *crtc; > + > + mode_set = &fb_helper->crtc_info[i].mode_set; > + crtc = mode_set->crtc; > + > + /* > + * Only call drm_crtc_wait_one_vblank for crtcs that > + * are currently active. > + */ > + if (!crtc->enabled) > + continue; crtc->enabled != crtc->active, and drm_crtc_vblank_get only works when the crtc is active. This means this ioctl will fail if the display is suspended using dpms off/FB_BLANK. Is that what you want? > + > + ret = drm_crtc_vblank_get(crtc); > + if (!ret) { > + drm_crtc_wait_one_vblank(crtc); > + drm_crtc_vblank_put(crtc); > + } else break; Probably you also need some locking here, drm_modeset_lock(&crtc->mutex); should be enough. Without that you might race with a dpms off. Might need more locks, not entirely sure, perhaps also dev->mode_config.mutex for fbdev emulation state. -Daniel > + } > + return ret; > + default: > + return -ENOTTY; > + } > + > + return 0; > +} > +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 5b4aa35..121af93 100644 > --- a/include/drm/drm_fb_helper.h > +++ b/include/drm/drm_fb_helper.h > @@ -278,6 +278,8 @@ void drm_fb_helper_set_suspend(struct drm_fb_helper *fb_helper, int state); > > 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); > -- > 1.9.1 > > _______________________________________________ > dri-devel mailing list > dri-devel@xxxxxxxxxxxxxxxxxxxxx > https://lists.freedesktop.org/mailman/listinfo/dri-devel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
