On 03/08/2012 08:34 PM, Laurent Pinchart wrote: > The fb_videomode structure stores the front porch and back porch in the > right_margin and left_margin fields respectively. right_margin should > thus be computed with hsync_start - hdisplay, and left_margin with > htotal - hsync_end. The same holds for the vertical direction. > > Active Front Sync Back > Region Porch Porch > <-------------------><----------------><-------------><----------------> > > //////////////////| > ////////////////// | > ////////////////// |.................. .................. > _______________ > > <------ xres -------><- right_margin -><- hsync_len -><- left_margin --> > > <---- hdisplay -----> > <------------ hsync_start ------------> > <--------------------- hsync_end --------------------> > <--------------------------------- htotal -----------------------------> > > Fix the fb_videomode<-> drm_mode_modeinfo conversion functions > accordingly. > > Signed-off-by: Laurent Pinchart<laurent.pinchart at ideasonboard.com> > --- > drivers/gpu/drm/exynos/exynos_drm_connector.c | 16 ++++++++-------- > 1 files changed, 8 insertions(+), 8 deletions(-) > > While trying to understand how the fb_videomode and drm_mode_modeinfo fields > map to each other, I found what might be a bug in the Exynos DRM driver. Could > you please check and confirm that my understanding is correct ?
Good catch. You can refer Documentation/fb/framebuffer.txt to know in detail. Acked-by: Joonyoung Shim <jy0922.shim at samsung.com> Thanks. > diff --git a/drivers/gpu/drm/exynos/exynos_drm_connector.c > b/drivers/gpu/drm/exynos/exynos_drm_connector.c > index d620b07..7bb1dca 100644 > --- a/drivers/gpu/drm/exynos/exynos_drm_connector.c > +++ b/drivers/gpu/drm/exynos/exynos_drm_connector.c > @@ -52,14 +52,14 @@ convert_to_display_mode(struct drm_display_mode *mode, > mode->vrefresh = timing->refresh; > > mode->hdisplay = timing->xres; > - mode->hsync_start = mode->hdisplay + timing->left_margin; > + mode->hsync_start = mode->hdisplay + timing->right_margin; > mode->hsync_end = mode->hsync_start + timing->hsync_len; > - mode->htotal = mode->hsync_end + timing->right_margin; > + mode->htotal = mode->hsync_end + timing->left_margin; > > mode->vdisplay = timing->yres; > - mode->vsync_start = mode->vdisplay + timing->upper_margin; > + mode->vsync_start = mode->vdisplay + timing->lower_margin; > mode->vsync_end = mode->vsync_start + timing->vsync_len; > - mode->vtotal = mode->vsync_end + timing->lower_margin; > + mode->vtotal = mode->vsync_end + timing->upper_margin; > > if (timing->vmode& FB_VMODE_INTERLACED) > mode->flags |= DRM_MODE_FLAG_INTERLACE; > @@ -81,14 +81,14 @@ convert_to_video_timing(struct fb_videomode *timing, > timing->refresh = drm_mode_vrefresh(mode); > > timing->xres = mode->hdisplay; > - timing->left_margin = mode->hsync_start - mode->hdisplay; > + timing->right_margin = mode->hsync_start - mode->hdisplay; > timing->hsync_len = mode->hsync_end - mode->hsync_start; > - timing->right_margin = mode->htotal - mode->hsync_end; > + timing->left_margin = mode->htotal - mode->hsync_end; > > timing->yres = mode->vdisplay; > - timing->upper_margin = mode->vsync_start - mode->vdisplay; > + timing->lower_margin = mode->vsync_start - mode->vdisplay; > timing->vsync_len = mode->vsync_end - mode->vsync_start; > - timing->lower_margin = mode->vtotal - mode->vsync_end; > + timing->upper_margin = mode->vtotal - mode->vsync_end; > > if (mode->flags& DRM_MODE_FLAG_INTERLACE) > timing->vmode = FB_VMODE_INTERLACED;
