drm/nouveau: prefer XBGR2101010 for addfb ioctl

commit c20bb155c2c5acb775f68be5d84fe679687c3c1e upstream.

Nouveau only exposes support for XBGR2101010. Prior to the atomic
conversion, drm would pass in the wrong format in the framebuffer, but
it was always ignored -- both userspace (xf86-video-nouveau) and the
kernel driver agreed on the layout, so the fact that the format was
wrong didn't matter.

With the atomic conversion, nouveau all of a sudden started caring about
the exact format, and so the previously-working code in
xf86-video-nouveau no longer functioned since the (internally-assigned)
format from the addfb ioctl was wrong.

This change adds infrastructure to allow a drm driver to specify that it
prefers the XBGR format variant for the addfb ioctl, and makes nouveau's
nv50 display driver set it. (Prior gens had no support for 30bpp at all.)

Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
Cc: stable@vger.kernel.org # v4.10+
Acked-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20180203191123.31507-1-imirkin@alum.mit.edu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpu/drm/drm_framebuffer.c b/drivers/gpu/drm/drm_framebuffer.c
index 279c1035c12dadf30794a89209084e8617058dec..5e1f1e2deb5223ea79bc800d273e9c423ff0dd2e 100644 (file)
--- a/drivers/gpu/drm/drm_framebuffer.c
+++ b/drivers/gpu/drm/drm_framebuffer.c
@@ -118,6 +118,10 @@ int drm_mode_addfb(struct drm_device *dev,
        r.pixel_format = drm_mode_legacy_fb_format(or->bpp, or->depth);
        r.handles[0] = or->handle;
 
+       if (r.pixel_format == DRM_FORMAT_XRGB2101010 &&
+           dev->driver->driver_features & DRIVER_PREFER_XBGR_30BPP)
+               r.pixel_format = DRM_FORMAT_XBGR2101010;
+
        ret = drm_mode_addfb2(dev, &r, file_priv);
        if (ret)
                return ret;

diff --git a/drivers/gpu/drm/nouveau/nv50_display.c b/drivers/gpu/drm/nouveau/nv50_display.c
index 584466ef688f5f965acf14de06f06a217bc1afab..325bff420f5ac3830af7f6a0c7bbcc337aba1362 100644 (file)
--- a/drivers/gpu/drm/nouveau/nv50_display.c
+++ b/drivers/gpu/drm/nouveau/nv50_display.c
@@ -4426,6 +4426,7 @@ nv50_display_create(struct drm_device *dev)
        nouveau_display(dev)->fini = nv50_display_fini;
        disp->disp = &nouveau_display(dev)->disp;
        dev->mode_config.funcs = &nv50_disp_func;
+       dev->driver->driver_features |= DRIVER_PREFER_XBGR_30BPP;
        if (nouveau_atomic)
                dev->driver->driver_features |= DRIVER_ATOMIC;
 

diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h
index 412e83a4d3dba895355b6813f0e9410a7eeecef4..29c839ed656b7a00c98c997200bd712bbe0d4c64 100644 (file)
--- a/include/drm/drm_drv.h
+++ b/include/drm/drm_drv.h
@@ -55,6 +55,7 @@ struct drm_mode_create_dumb;
 #define DRIVER_ATOMIC                  0x10000
 #define DRIVER_KMS_LEGACY_CONTEXT      0x20000
 #define DRIVER_SYNCOBJ                  0x40000
+#define DRIVER_PREFER_XBGR_30BPP        0x80000
 
 /**
  * struct drm_driver - DRM driver structure