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From:   Zhenneng Li <lizhenneng@kylinos.cn>
To:     Alex Deucher <alexander.deucher@amd.com>
Cc:     =?UTF-8?q?Christian=20K=C3=B6nig?= <christian.koenig@amd.com>,
        Xinhui.Pan@amd.com, David Airlie <airlied@gmail.com>,
        Daniel Vetter <daniel@ffwll.ch>, amd-gfx@lists.freedesktop.org,
        dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org,
        Zhenneng Li <lizhenneng@kylinos.cn>
Subject: [PATCH] drm/amdgpu: add mb for si
Date:   Fri, 18 Nov 2022 15:48:10 +0800
Message-Id: <20221118074810.380368-1-lizhenneng@kylinos.cn>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

During reboot test on arm64 platform, it may failure on boot,
so add this mb in smc.

The error message are as follows:
[    6.996395][ 7] [  T295] [drm:amdgpu_device_ip_late_init [amdgpu]] *ERROR*
			    late_init of IP block <si_dpm> failed -22
[    7.006919][ 7] [  T295] amdgpu 0000:04:00.0: amdgpu_device_ip_late_init failed
[    7.014224][ 7] [  T295] amdgpu 0000:04:00.0: Fatal error during GPU init

Signed-off-by: Zhenneng Li <lizhenneng@kylinos.cn>
---
 drivers/gpu/drm/amd/pm/legacy-dpm/si_smc.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/amd/pm/legacy-dpm/si_smc.c b/drivers/gpu/drm/amd/pm/legacy-dpm/si_smc.c
index 8f994ffa9cd1..c7656f22278d 100644
--- a/drivers/gpu/drm/amd/pm/legacy-dpm/si_smc.c
+++ b/drivers/gpu/drm/amd/pm/legacy-dpm/si_smc.c
@@ -155,6 +155,8 @@ bool amdgpu_si_is_smc_running(struct amdgpu_device *adev)
 	u32 rst = RREG32_SMC(SMC_SYSCON_RESET_CNTL);
 	u32 clk = RREG32_SMC(SMC_SYSCON_CLOCK_CNTL_0);
 
+	mb();
+
 	if (!(rst & RST_REG) && !(clk & CK_DISABLE))
 		return true;
 
-- 
2.25.1