From 865afb11949e5bf4bb32d9a2aa9867c1ac4d8da0 Mon Sep 17 00:00:00 2001 From: Stefan Agner Date: Tue, 11 Oct 2016 16:15:04 -0700 Subject: [PATCH] drm/fb-helper: reject any changes to the fbdev The current fbdev emulation does not allow to push back changes in width, height or depth to KMS, hence reject any changes with an error. This makes sure that fbdev ioctl's fail properly and user space does not assume that changes succeeded. Signed-off-by: Stefan Agner Reviewed-by: Tomi Valkeinen Signed-off-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/20161011231504.17688-1-stefan@agner.ch --- drivers/gpu/drm/drm_fb_helper.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index 22d4f0e22101..8fffac8c5c75 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -1209,11 +1209,14 @@ int drm_fb_helper_check_var(struct fb_var_screeninfo *var, if (var->pixclock != 0 || in_dbg_master()) return -EINVAL; - /* Need to resize the fb object !!! */ - if (var->bits_per_pixel > fb->bits_per_pixel || - var->xres > fb->width || var->yres > fb->height || - var->xres_virtual > fb->width || var->yres_virtual > fb->height) { - DRM_DEBUG("fb userspace requested width/height/bpp is greater than current fb " + /* + * Changes struct fb_var_screeninfo are currently not pushed back + * to KMS, hence fail if different settings are requested. + */ + if (var->bits_per_pixel != fb->bits_per_pixel || + var->xres != fb->width || var->yres != fb->height || + var->xres_virtual != fb->width || var->yres_virtual != fb->height) { + DRM_DEBUG("fb userspace requested width/height/bpp different than current fb " "request %dx%d-%d (virtual %dx%d) > %dx%d-%d\n", var->xres, var->yres, var->bits_per_pixel, var->xres_virtual, var->yres_virtual,