From: Evan Quan evan.quan@amd.com
commit adcf949e664a8b04df2fb8aa916892e58561653c upstream.
SMU had set all the necessary fields for a link width switch but the width switch wasn't occurring because the link was idle in the L1 state. Setting LC_L1_RECONFIG_EN=0x1 will allow width switches to also be initiated while in L1 instead of waiting until the link is back in L0.
Signed-off-by: Evan Quan evan.quan@amd.com Reviewed-by: Lijo Lazar lijo.lazar@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/gpu/drm/amd/amdgpu/amdgpu_nbio.h | 1 + drivers/gpu/drm/amd/amdgpu/nbio_v2_3.c | 13 +++++++++++++ drivers/gpu/drm/amd/amdgpu/nv.c | 3 +++ 3 files changed, 17 insertions(+)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_nbio.h +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_nbio.h @@ -90,6 +90,7 @@ struct amdgpu_nbio_funcs { bool enable); void (*program_aspm)(struct amdgpu_device *adev); void (*apply_lc_spc_mode_wa)(struct amdgpu_device *adev); + void (*apply_l1_link_width_reconfig_wa)(struct amdgpu_device *adev); };
struct amdgpu_nbio { --- a/drivers/gpu/drm/amd/amdgpu/nbio_v2_3.c +++ b/drivers/gpu/drm/amd/amdgpu/nbio_v2_3.c @@ -490,6 +490,18 @@ static void nbio_v2_3_apply_lc_spc_mode_ } }
+static void nbio_v2_3_apply_l1_link_width_reconfig_wa(struct amdgpu_device *adev) +{ + uint32_t reg_data = 0; + + if (adev->asic_type != CHIP_NAVI10) + return; + + reg_data = RREG32_PCIE(smnPCIE_LC_LINK_WIDTH_CNTL); + reg_data |= PCIE_LC_LINK_WIDTH_CNTL__LC_L1_RECONFIG_EN_MASK; + WREG32_PCIE(smnPCIE_LC_LINK_WIDTH_CNTL, reg_data); +} + const struct amdgpu_nbio_funcs nbio_v2_3_funcs = { .get_hdp_flush_req_offset = nbio_v2_3_get_hdp_flush_req_offset, .get_hdp_flush_done_offset = nbio_v2_3_get_hdp_flush_done_offset, @@ -512,4 +524,5 @@ const struct amdgpu_nbio_funcs nbio_v2_3 .enable_aspm = nbio_v2_3_enable_aspm, .program_aspm = nbio_v2_3_program_aspm, .apply_lc_spc_mode_wa = nbio_v2_3_apply_lc_spc_mode_wa, + .apply_l1_link_width_reconfig_wa = nbio_v2_3_apply_l1_link_width_reconfig_wa, }; --- a/drivers/gpu/drm/amd/amdgpu/nv.c +++ b/drivers/gpu/drm/amd/amdgpu/nv.c @@ -1076,6 +1076,9 @@ static int nv_common_hw_init(void *handl if (adev->nbio.funcs->apply_lc_spc_mode_wa) adev->nbio.funcs->apply_lc_spc_mode_wa(adev);
+ if (adev->nbio.funcs->apply_l1_link_width_reconfig_wa) + adev->nbio.funcs->apply_l1_link_width_reconfig_wa(adev); + /* enable pcie gen2/3 link */ nv_pcie_gen3_enable(adev); /* enable aspm */