Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 5.12 368/700] drm/amd/display: fix potential gpu reset deadlock | Date | Mon, 12 Jul 2021 08:07:31 +0200 |
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From: Roman Li <Roman.Li@amd.com>
[ Upstream commit cf8b92a75646735136053ce51107bfa8cfc23191 ]
[Why] In gpu reset dc_lock acquired in dm_suspend(). Asynchronously handle_hpd_rx_irq can also be called through amdgpu_dm_irq_suspend->flush_work, which also tries to acquire dc_lock. That causes a deadlock.
[How] Check if amdgpu executing reset before acquiring dc_lock.
Signed-off-by: Lang Yu <Lang.Yu@amd.com> Signed-off-by: Roman Li <Roman.Li@amd.com> Reviewed-by: Qingqing Zhuo <Qingqing.Zhuo@amd.com> Acked-by: Wayne Lin <Wayne.Lin@amd.com> Tested-by: Daniel Wheeler <daniel.wheeler@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Sasha Levin <sashal@kernel.org> --- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c index eed494630583..d95569e0e53a 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -2624,13 +2624,15 @@ static void handle_hpd_rx_irq(void *param) } } - mutex_lock(&adev->dm.dc_lock); + if (!amdgpu_in_reset(adev)) + mutex_lock(&adev->dm.dc_lock); #ifdef CONFIG_DRM_AMD_DC_HDCP result = dc_link_handle_hpd_rx_irq(dc_link, &hpd_irq_data, NULL); #else result = dc_link_handle_hpd_rx_irq(dc_link, NULL, NULL); #endif - mutex_unlock(&adev->dm.dc_lock); + if (!amdgpu_in_reset(adev)) + mutex_unlock(&adev->dm.dc_lock); out: if (result && !is_mst_root_connector) { -- 2.30.2
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