drm/amd/display: Fix deadlock when flushing irq

BugLink: http://bugs.launchpad.net/bugs/1778265
commit ad64dc0137968f09800e58174bbfd5eac9fe5418 upstream.

Lock irq table when reading a work in queue,
unlock to flush the work, lock again till all tasks
are cleared

Signed-off-by: Mikita Lipski <mikita.lipski@amd.com>
Reviewed-by: Harry Wentland <Harry.Wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_irq.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_irq.c
index ca5d0d1581dc7586c6d50de57aa61d3364a6bf56..7a4a347216ff37430f1ee649e698a476e3739262 100644 (file)
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_irq.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_irq.c
@@ -400,14 +400,15 @@ void amdgpu_dm_irq_fini(struct amdgpu_device *adev)
 {
        int src;
        struct irq_list_head *lh;
+       unsigned long irq_table_flags;
        DRM_DEBUG_KMS("DM_IRQ: releasing resources.\n");
-
        for (src = 0; src < DAL_IRQ_SOURCES_NUMBER; src++) {
-
+               DM_IRQ_TABLE_LOCK(adev, irq_table_flags);
                /* The handler was removed from the table,
                 * it means it is safe to flush all the 'work'
                 * (because no code can schedule a new one). */
                lh = &adev->dm.irq_handler_list_low_tab[src];
+               DM_IRQ_TABLE_UNLOCK(adev, irq_table_flags);
                flush_work(&lh->work);
        }