From 8d4f4b82155cc6774d0fd8aaafb882566f7fd5fb Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Fri, 15 Jun 2018 20:39:39 +0300 Subject: [PATCH] drm: Document mode_config.max_width/height as the max fb dimensions MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The meaning of the mode_config max_width/height fields has not been entirely clear. They are used both as the max framebuffer dimensions, and they are also used by drm_mode_getconnector() to filter out any mode whose hdisplay/vdisplay exceed those limits. Let's put it in writing that max_width/height only refrer to the max framebuffer dimensions, and should those be higher than the hardware limits for display timings the driver must validate the latter using some other means. We'll keep the max_width/height usage in drm_mode_getconnector() because setcrtc treats hdisplay/vdisplay also as the primary plane width, and having a plane bigger than the max fb size doesn't make much sense (if we ignore scaling that is). It all works out fine as long as the max fb dimensions are at least equal to the max timing limits. If the opposite were true we may want to rethink what drm_mode_getconnector() does. Maybe do the mode filtering only for non-atomic userspace? Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20180615173939.11353-1-ville.syrjala@linux.intel.com Reviewed-by: Manasi Navare --- include/drm/drm_mode_config.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h index f4a173c..a0b202e 100644 --- a/include/drm/drm_mode_config.h +++ b/include/drm/drm_mode_config.h @@ -329,10 +329,10 @@ struct drm_mode_config_funcs { /** * struct drm_mode_config - Mode configuration control structure - * @min_width: minimum pixel width on this device - * @min_height: minimum pixel height on this device - * @max_width: maximum pixel width on this device - * @max_height: maximum pixel height on this device + * @min_width: minimum fb pixel width on this device + * @min_height: minimum fb pixel height on this device + * @max_width: maximum fb pixel width on this device + * @max_height: maximum fb pixel height on this device * @funcs: core driver provided mode setting functions * @fb_base: base address of the framebuffer * @poll_enabled: track polling support for this device -- 2.7.4