drm/nouveau/fbcon: add module parameter to select bits-per-pixel

Useful for debugging.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

diff --git a/drivers/gpu/drm/nouveau/nouveau_fbcon.c b/drivers/gpu/drm/nouveau/nouveau_fbcon.c
index ee5d1dc2eaf5ac06433e91f5c5b3ffec3c3a05ff..85c1f10bc2b67651222731f1b9703278328c90e8 100644 (file)
--- a/drivers/gpu/drm/nouveau/nouveau_fbcon.c
+++ b/drivers/gpu/drm/nouveau/nouveau_fbcon.c
@@ -56,6 +56,10 @@ MODULE_PARM_DESC(nofbaccel, "Disable fbcon acceleration");
 int nouveau_nofbaccel = 0;
 module_param_named(nofbaccel, nouveau_nofbaccel, int, 0400);
 
+MODULE_PARM_DESC(fbcon_bpp, "fbcon bits-per-pixel (default: auto)");
+static int nouveau_fbcon_bpp;
+module_param_named(fbcon_bpp, nouveau_fbcon_bpp, int, 0400);
+
 static void
 nouveau_fbcon_fillrect(struct fb_info *info, const struct fb_fillrect *rect)
 {
@@ -488,7 +492,7 @@ nouveau_fbcon_init(struct drm_device *dev)
 {
        struct nouveau_drm *drm = nouveau_drm(dev);
        struct nouveau_fbdev *fbcon;
-       int preferred_bpp;
+       int preferred_bpp = nouveau_fbcon_bpp;
        int ret;
 
        if (!dev->mode_config.num_crtc ||
@@ -512,13 +516,15 @@ nouveau_fbcon_init(struct drm_device *dev)
        if (ret)
                goto fini;
 
-       if (drm->client.device.info.ram_size <= 32 * 1024 * 1024)
-               preferred_bpp = 8;
-       else
-       if (drm->client.device.info.ram_size <= 64 * 1024 * 1024)
-               preferred_bpp = 16;
-       else
-               preferred_bpp = 32;
+       if (preferred_bpp != 8 && preferred_bpp != 16 && preferred_bpp != 32) {
+               if (drm->client.device.info.ram_size <= 32 * 1024 * 1024)
+                       preferred_bpp = 8;
+               else
+               if (drm->client.device.info.ram_size <= 64 * 1024 * 1024)
+                       preferred_bpp = 16;
+               else
+                       preferred_bpp = 32;
+       }
 
        /* disable all the possible outputs/crtcs before entering KMS mode */
        if (!drm_drv_uses_atomic_modeset(dev))