drm/nouveau: by default use low bpp framebuffer on low memory cards

Framebuffer's BPP is not that important but can waste significant part
of memory on low-VRAM cards. Lower it to 8bpp on < 32MB cards and to
16bpp on 64MB cards. It can still be overridden by video= option.

Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
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 14a8627efe4d0499515d596cbaf665fbfbade690..3a4cc32b9e44c44f92fab174792778def49197f4 100644 (file)
--- a/drivers/gpu/drm/nouveau/nouveau_fbcon.c
+++ b/drivers/gpu/drm/nouveau/nouveau_fbcon.c
@@ -487,6 +487,7 @@ int nouveau_fbcon_init(struct drm_device *dev)
 {
        struct drm_nouveau_private *dev_priv = dev->dev_private;
        struct nouveau_fbdev *nfbdev;
+       int preferred_bpp;
        int ret;
 
        nfbdev = kzalloc(sizeof(struct nouveau_fbdev), GFP_KERNEL);
@@ -505,7 +506,15 @@ int nouveau_fbcon_init(struct drm_device *dev)
        }
 
        drm_fb_helper_single_add_all_connectors(&nfbdev->helper);
-       drm_fb_helper_initial_config(&nfbdev->helper, 32);
+
+       if (dev_priv->vram_size <= 32 * 1024 * 1024)
+               preferred_bpp = 8;
+       else if (dev_priv->vram_size <= 64 * 1024 * 1024)
+               preferred_bpp = 16;
+       else
+               preferred_bpp = 32;
+
+       drm_fb_helper_initial_config(&nfbdev->helper, preferred_bpp);
        return 0;
 }