drm/nouveau: don't use the default pll limits in table v2.1 on nv50+ cards

This fixes issues bug 30370 and prevents another possible divide by zero on
the original nv50 cards, by returning -ENOENT

Signed-off-by: Emil Velikov <eeydev@nottingham.ac.uk>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/gpu/drm/nouveau/nouveau_bios.c b/drivers/gpu/drm/nouveau/nouveau_bios.c
index c66d4567a2e..53f4eba65cb 100644
--- a/drivers/gpu/drm/nouveau/nouveau_bios.c
+++ b/drivers/gpu/drm/nouveau/nouveau_bios.c
@@ -4890,6 +4890,12 @@ int get_pll_limits(struct drm_device *dev, uint32_t limit_match, struct pll_lims
                                 break;
                         }
 
+                if ((dev_priv->card_type >= NV_50) && (pllindex == 0)) {
+                        NV_ERROR(dev, "Register 0x%08x not found in PLL "
+                                 "limits table", pll_lim->reg);
+                        return -ENOENT;
+                }
+
                 pll_rec = &bios->data[plloffs + recordlen * pllindex];
 
                 BIOSLOG(bios, "Loading PLL limits for reg 0x%08x\n",