drm/amdgpu: fix NAK-G generation during PCI-e link width switch

A lot of NAK-G being generated when link widht switching is happening.
WA for this issue is to program the SPC to 4 symbols per clock during
bootup when the native PCIE width is x4.

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
This commit is contained in:
Evan Quan 2021-05-25 12:08:53 +08:00 committed by Alex Deucher
parent 9c26ddb1c5
commit 5a5da8ae95
3 changed files with 32 additions and 0 deletions

View File

@ -93,6 +93,7 @@ struct amdgpu_nbio_funcs {
void (*enable_aspm)(struct amdgpu_device *adev,
bool enable);
void (*program_aspm)(struct amdgpu_device *adev);
void (*apply_lc_spc_mode_wa)(struct amdgpu_device *adev);
};
struct amdgpu_nbio {

View File

@ -51,6 +51,8 @@
#define mmBIF_MMSCH1_DOORBELL_RANGE 0x01d8
#define mmBIF_MMSCH1_DOORBELL_RANGE_BASE_IDX 2
#define smnPCIE_LC_LINK_WIDTH_CNTL 0x11140288
static void nbio_v2_3_remap_hdp_registers(struct amdgpu_device *adev)
{
WREG32_SOC15(NBIO, 0, mmREMAP_HDP_MEM_FLUSH_CNTL,
@ -463,6 +465,31 @@ static void nbio_v2_3_program_aspm(struct amdgpu_device *adev)
WREG32_PCIE(smnPCIE_LC_CNTL3, data);
}
static void nbio_v2_3_apply_lc_spc_mode_wa(struct amdgpu_device *adev)
{
uint32_t reg_data = 0;
uint32_t link_width = 0;
if (!((adev->asic_type >= CHIP_NAVI10) &&
(adev->asic_type <= CHIP_NAVI12)))
return;
reg_data = RREG32_PCIE(smnPCIE_LC_LINK_WIDTH_CNTL);
link_width = (reg_data & PCIE_LC_LINK_WIDTH_CNTL__LC_LINK_WIDTH_RD_MASK)
>> PCIE_LC_LINK_WIDTH_CNTL__LC_LINK_WIDTH_RD__SHIFT;
/*
* Program PCIE_LC_CNTL6.LC_SPC_MODE_8GT to 0x2 (4 symbols per clock data)
* if link_width is 0x3 (x4)
*/
if (0x3 == link_width) {
reg_data = RREG32_PCIE(smnPCIE_LC_CNTL6);
reg_data &= ~PCIE_LC_CNTL6__LC_SPC_MODE_8GT_MASK;
reg_data |= (0x2 << PCIE_LC_CNTL6__LC_SPC_MODE_8GT__SHIFT);
WREG32_PCIE(smnPCIE_LC_CNTL6, 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,
@ -484,4 +511,5 @@ const struct amdgpu_nbio_funcs nbio_v2_3_funcs = {
.remap_hdp_registers = nbio_v2_3_remap_hdp_registers,
.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,
};

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@ -1411,6 +1411,9 @@ static int nv_common_hw_init(void *handle)
{
struct amdgpu_device *adev = (struct amdgpu_device *)handle;
if (adev->nbio.funcs->apply_lc_spc_mode_wa)
adev->nbio.funcs->apply_lc_spc_mode_wa(adev);
/* enable pcie gen2/3 link */
nv_pcie_gen3_enable(adev);
/* enable aspm */