From 6f81b2d047c59eb77cd04795a44245d6a52cdaec Mon Sep 17 00:00:00 2001 From: limingyu Date: Wed, 22 Apr 2020 17:01:19 +0800 Subject: [PATCH] drm/amdgpu: Init data to avoid oops while reading pp_num_states. For chip like CHIP_OLAND with si enabled(amdgpu.si_support=1), the amdgpu will expose pp_num_states to the /sys directory. In this moment, read the pp_num_states file will excute the amdgpu_get_pp_num_states func. In our case, the data hasn't been initialized, so the kernel will access some ilegal address, trigger the segmentfault and system will reboot soon: uos@uos-PC:~$ cat /sys/devices/pci0000\:00/0000\:00\:00.0/0000\:01\:00 .0/pp_num_states Message from syslogd@uos-PC at Apr 22 09:26:20 ... kernel:[ 82.154129] Internal error: Oops: 96000004 [#1] SMP This patch aims to fix this problem, avoid that reading file triggers the kernel sementfault. Signed-off-by: limingyu Signed-off-by: zhoubinbin Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c index abe94a5..49e2e43 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c @@ -444,8 +444,11 @@ static ssize_t amdgpu_get_pp_num_states(struct device *dev, ret = smu_get_power_num_states(&adev->smu, &data); if (ret) return ret; - } else if (adev->powerplay.pp_funcs->get_pp_num_states) + } else if (adev->powerplay.pp_funcs->get_pp_num_states) { amdgpu_dpm_get_pp_num_states(adev, &data); + } else { + memset(&data, 0, sizeof(data)); + } pm_runtime_mark_last_busy(ddev->dev); pm_runtime_put_autosuspend(ddev->dev); -- 2.7.4