drm/amdgpu: Add HAINAN clock adjustment

[ Upstream commit 49fe2c5 ]

This patch limits the clock speeds of the AMD Radeon R5 M420 GPU from
850/1000MHz (core/memory) to 800/950 MHz, making it work stably. This
patch is for amdgpu.

Signed-off-by: decce6 <decce6@proton.me>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

Author: decce6

drivers/gpu/drm/amd/pm/legacy-dpm/si_dpm.c

@@ -3449,6 +3449,11 @@ static void si_apply_state_adjust_rules(struct amdgpu_device *adev,
 			max_sclk = 60000;
 			max_mclk = 80000;
 		}
+		if ((adev->pdev->device == 0x666f) &&
+		    (adev->pdev->revision == 0x00)) {
+			max_sclk = 80000;
+			max_mclk = 95000;
+		}
 	} else if (adev->asic_type == CHIP_OLAND) {
 		if ((adev->pdev->revision == 0xC7) ||
 		    (adev->pdev->revision == 0x80) ||