drm/radeon/kms: fix divide by 0 in clocks code

[safe/jmp/linux-2.6] / drivers / gpu / drm / radeon / radeon_clocks.c

diff --git a/drivers/gpu/drm/radeon/radeon_clocks.c b/drivers/gpu/drm/radeon/radeon_clocks.c
index a813541..2c541e0 100644 (file)
--- a/drivers/gpu/drm/radeon/radeon_clocks.c
+++ b/drivers/gpu/drm/radeon/radeon_clocks.c
@@ -44,6 +44,10 @@ uint32_t radeon_legacy_get_engine_clock(struct radeon_device *rdev)
 
        ref_div =
            RREG32_PLL(RADEON_M_SPLL_REF_FB_DIV) & RADEON_M_SPLL_REF_DIV_MASK;
+
+       if (ref_div == 0)
+               return 0;
+
        sclk = fb_div / ref_div;
 
        post_div = RREG32_PLL(RADEON_SCLK_CNTL) & RADEON_SCLK_SRC_SEL_MASK;
@@ -70,6 +74,10 @@ static uint32_t radeon_legacy_get_memory_clock(struct radeon_device *rdev)
 
        ref_div =
            RREG32_PLL(RADEON_M_SPLL_REF_FB_DIV) & RADEON_M_SPLL_REF_DIV_MASK;
+
+       if (ref_div == 0)
+               return 0;
+
        mclk = fb_div / ref_div;
 
        post_div = RREG32_PLL(RADEON_MCLK_CNTL) & 0x7;