drm/amdgpu: Fix PCIe lane width calculation
commit 41212e2fe72b26ded7ed78224d9eab720c2891e2 upstream.
The calculation of the lane widths via ATOM_PPLIB_PCIE_LINK_WIDTH_MASK and
ATOM_PPLIB_PCIE_LINK_WIDTH_SHIFT macros did not increment the resulting
value, per the comment in pptable.h ("lanes - 1"), and per usage elsewhere.
Port of the radeon fix to amdgpu.
Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Chunming Zhou <david1.zhou@amd.com>
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=102553
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/si_dpm.c b/drivers/gpu/drm/amd/amdgpu/si_dpm.c
index 002862b..3fa8320 100644
--- a/drivers/gpu/drm/amd/amdgpu/si_dpm.c
+++ b/drivers/gpu/drm/amd/amdgpu/si_dpm.c
@@ -6449,9 +6449,9 @@
{
u32 lane_width;
u32 new_lane_width =
- (amdgpu_new_state->caps & ATOM_PPLIB_PCIE_LINK_WIDTH_MASK) >> ATOM_PPLIB_PCIE_LINK_WIDTH_SHIFT;
+ ((amdgpu_new_state->caps & ATOM_PPLIB_PCIE_LINK_WIDTH_MASK) >> ATOM_PPLIB_PCIE_LINK_WIDTH_SHIFT) + 1;
u32 current_lane_width =
- (amdgpu_current_state->caps & ATOM_PPLIB_PCIE_LINK_WIDTH_MASK) >> ATOM_PPLIB_PCIE_LINK_WIDTH_SHIFT;
+ ((amdgpu_current_state->caps & ATOM_PPLIB_PCIE_LINK_WIDTH_MASK) >> ATOM_PPLIB_PCIE_LINK_WIDTH_SHIFT) + 1;
if (new_lane_width != current_lane_width) {
amdgpu_set_pcie_lanes(adev, new_lane_width);