SDMA ULV can benefit low-power modes, but can sometimes cause
latency increases in small SDMA transfers. Server SKUs have a
different trade-off space in this domain, so this configures
the server SKUs' ULV hysteresis times differently than consumer
SKUs'.
Signed-off-by: Joseph Greathouse <joseph.greatho...@amd.com>
Change-Id: Ifc33aa857714c4c209b19a5d44e0a05c478db195
---
drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c | 32 ++++++++++++++++++++++++++
1 file changed, 32 insertions(+)
diff --git a/drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c
b/drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c
index 2f1f47de9634..58382646d962 100644
--- a/drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c
@@ -505,6 +505,36 @@ static void sdma_v4_0_init_golden_registers(struct
amdgpu_device *adev)
}
}
+static void sdma_v4_0_setup_ulv(struct amdgpu_device *adev)
+{
+ int i;
+
+ /*
+ * The only chips with SDMAv4 and ULV are VG10 and VG20.
+ * Server SKUs take a different hysteresis setting from other SKUs.
+ */
+ switch (adev->asic_type) {
+ case CHIP_VEGA10:
+ if (adev->pdev->device == 0x6860)
+ break;
+ return;
+ case CHIP_VEGA20:
+ if (adev->pdev->device == 0x66a1)
+ break;
+ return;
+ default:
+ return;
+ }
+
+ for (i = 0; i < adev->sdma.num_instances; i++) {
+ uint32_t temp;
+
+ temp = RREG32_SDMA(i, mmSDMA0_ULV_CNTL);
+ temp = REG_SET_FIELD(temp, SDMA0_ULV_CNTL, HYSTERESIS, 0x0);
+ WREG32_SDMA(i, mmSDMA0_ULV_CNTL, temp);
+ }
+}
+
static int sdma_v4_0_init_inst_ctx(struct amdgpu_sdma_instance *sdma_inst)
{
int err = 0;
@@ -1813,6 +1843,8 @@ static int sdma_v4_0_late_init(void *handle)
.cb = sdma_v4_0_process_ras_data_cb,
};
+ sdma_v4_0_setup_ulv(adev);
+
if (adev->sdma.funcs && adev->sdma.funcs->reset_ras_error_count)
adev->sdma.funcs->reset_ras_error_count(adev);
--
2.20.1
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