drm/amdgpu: fix xclk freq on CHIP_STONEY

commit b447b079cf3a9971ea4d31301e673f49612ccc18 upstream.

According to Alex, most APUs from that time seem to have the same issue
(vbios says 48Mhz, actual is 100Mhz).  I only have a CHIP_STONEY so I
limit the fixup to CHIP_STONEY

Signed-off-by: Chia-I Wu <olvaffe@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpu/drm/amd/amdgpu/vi.c b/drivers/gpu/drm/amd/amdgpu/vi.c
index d6c37c9..53a3bb7 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/vi.c
+++ b/drivers/gpu/drm/amd/amdgpu/vi.c
@@ -542,8 +542,15 @@ static u32 vi_get_xclk(struct amdgpu_device *adev)
        u32 reference_clock = adev->clock.spll.reference_freq;
        u32 tmp;
 
-       if (adev->flags & AMD_IS_APU)
-               return reference_clock;
+       if (adev->flags & AMD_IS_APU) {
+               switch (adev->asic_type) {
+               case CHIP_STONEY:
+                       /* vbios says 48Mhz, but the actual freq is 100Mhz */
+                       return 10000;
+               default:
+                       return reference_clock;
+               }
+       }
 
        tmp = RREG32_SMC(ixCG_CLKPIN_CNTL_2);
        if (REG_GET_FIELD(tmp, CG_CLKPIN_CNTL_2, MUX_TCLK_TO_XCLK))