Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
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>,
        Pan Xinhui <Xinhui.Pan@amd.com>,
        David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        Sumit Semwal <sumit.semwal@linaro.org>,
        Andrey Grodzovsky <andrey.grodzovsky@amd.com>,
        Evan Quan <evan.quan@amd.com>,
        Guchun Chen <guchun.chen@amd.com>,
        Jack Zhang <Jack.Zhang1@amd.com>,
        Lijo Lazar <lijo.lazar@amd.com>,
        Kevin Wang <kevin1.wang@amd.com>,
        amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org,
        linux-kernel@vger.kernel.org, linux-media@vger.kernel.org,
        linaro-mm-sig@lists.linaro.org, Zhenneng Li <lizhenneng@kylinos.cn>
Subject: [PATCH next,v2] kernel: Add 1 ms delay to init handler to fix s3 resume hang
Date:   Tue, 29 Mar 2022 11:05:47 +0800
Message-Id: <20220329030547.286265-1-lizhenneng@kylinos.cn>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

This is a workaround for s3 resume hang for r7 340(amdgpu).
When we test s3 with r7 340 on arm64 platform, graphics card will hang up,
the error message are as follows:
Mar  4 01:14:11 greatwall-GW-XXXXXX-XXX kernel: [    1.599374][ 7] [  T291] amdgpu 0000:02:00.0: fb0: amdgpudrmfb frame buffer device
Mar  4 01:14:11 greatwall-GW-XXXXXX-XXX kernel: [    1.612869][ 7] [  T291] [drm:amdgpu_device_ip_late_init [amdgpu]] *ERROR* late_init of IP block <si_dpm> failed -22
Mar  4 01:14:11 greatwall-GW-XXXXXX-XXX kernel: [    1.623392][ 7] [  T291] amdgpu 0000:02:00.0: amdgpu_device_ip_late_init failed
Mar  4 01:14:11 greatwall-GW-XXXXXX-XXX kernel: [    1.630696][ 7] [  T291] amdgpu 0000:02:00.0: Fatal error during GPU init
Mar  4 01:14:11 greatwall-GW-XXXXXX-XXX kernel: [    1.637477][ 7] [  T291] [drm] amdgpu: finishing device.

On the following hardware:
lspci -nn -s 05:00.0
05:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Oland [Radeon HD 8570 / R7 240/340 / Radeon 520 OEM] [1002:6611] (rev 87)

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

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index 3987ecb24ef4..1eced991b5b2 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -2903,6 +2903,8 @@ static void amdgpu_device_delayed_init_work_handler(struct work_struct *work)
 		container_of(work, struct amdgpu_device, delayed_init_work.work);
 	int r;
 
+	mdelay(1);
+
 	r = amdgpu_ib_ring_tests(adev);
 	if (r)
 		DRM_ERROR("ib ring test failed (%d).\n", r);
-- 
2.25.1