drm/fb-helper: Allow var->x/yres(_virtual) < fb->width/height again

commit 12ffed96d4369f086261ba2ee734fa8c932d7f55 upstream.

Otherwise this can also prevent modesets e.g. for switching VTs, when
multiple monitors with different native resolutions are connected.

The depths must match though, so keep the != test for that.

Also update the DRM_DEBUG output to be slightly more accurate, this
doesn't only affect requests from userspace.

Bugzilla: https://bugs.freedesktop.org/99841
Fixes: 865afb11949e ("drm/fb-helper: reject any changes to the fbdev")
Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
Reviewed-by: Daniel Stone <daniels@collabora.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170323085326.20185-1-michel@daenzer.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index ad531126667c309a067ec2019be92a40f2b272b0..e3da97b409bcf34e69be7aff465d14bdd12416a1 100644 (file)
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -1256,9 +1256,9 @@ int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
         * 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 "
+           var->xres > fb->width || var->yres > fb->height ||
+           var->xres_virtual > fb->width || var->yres_virtual > fb->height) {
+               DRM_DEBUG("fb requested width/height/bpp can't fit in 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,