drm/nvd0/disp: ignore clock set if no pclk

This happens somehow during init on a machine I have, and leads to a
divide-by-zero.

Lets avoid that...

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

1 files changed, 3 insertions, 1 deletions

diff --git a/drivers/gpu/drm/nouveau/nvd0_display.c b/drivers/gpu/drm/nouveau/nvd0_display.c
index 5e2b79bdcae0..421d301b3797 100644
--- a/drivers/gpu/drm/nouveau/nvd0_display.c
+++ b/drivers/gpu/drm/nouveau/nvd0_display.c
@@ -1661,7 +1661,9 @@ nvd0_display_unk2_handler(struct drm_device *dev, u32 crtc, u32 mask)
         }
 
         pclk = nv_rd32(dev, 0x660450 + (crtc * 0x300)) / 1000;
-        if (mask & 0x00010000) {
+        NV_DEBUG_KMS(dev, "PDISP: crtc %d pclk %d mask 0x%08x\n",
+                          crtc, pclk, mask);
+        if (pclk && (mask & 0x00010000)) {
                 nv50_crtc_set_clock(dev, crtc, pclk);
         }