[PATCH 2/2 v2] drm/i915: Replace alloc*workqueue with DRM helpers

[Jiasheng Jiang]

Replace alloc*workqueue with DRM helpers in order to avoid memory leak
Because in `drivers/gpu/drm/i915/i915_driver.c`, if
intel_modeset_init_noirq fails, its workqueues will not be destroyed.
And drop the destroy_workqueue in intel_modeset_driver_remove_noirq to
avoid double free.
Moreover, check the return value since the workqueue may be NULL and
cause NULL pointer dereference.

Fixes: c26a058680dc ("drm/i915: Use a high priority wq for nonblocking plane 
updates")
Fixes: 757fffcfdffb ("drm/i915: Put all non-blocking modesets onto an ordered 
wq")
Signed-off-by: Jiasheng Jiang <jiash...@iscas.ac.cn>
---
Changelog:

v1 -> v2:

1. Drop the destroy_workqueue in intel_modeset_driver_remove_noirq.
---
 drivers/gpu/drm/i915/display/intel_display.c | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_display.c 
b/drivers/gpu/drm/i915/display/intel_display.c
index 6c2686ecb62a..5cbec0af1773 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -41,6 +41,7 @@
 #include <drm/drm_damage_helper.h>
 #include <drm/drm_edid.h>
 #include <drm/drm_fourcc.h>
+#include <drm/drm_managed.h>
 #include <drm/drm_privacy_screen_consumer.h>
 #include <drm/drm_probe_helper.h>
 #include <drm/drm_rect.h>
@@ -8654,9 +8655,16 @@ int intel_modeset_init_noirq(struct drm_i915_private 
*i915)
 
        intel_dmc_ucode_init(i915);
 
-       i915->display.wq.modeset = alloc_ordered_workqueue("i915_modeset", 0);
-       i915->display.wq.flip = alloc_workqueue("i915_flip", WQ_HIGHPRI |
-                                               WQ_UNBOUND, 
WQ_UNBOUND_MAX_ACTIVE);
+       ret = drmm_alloc_ordered_workqueue(&i915->drm,
+                                          i915->display.wq.modeset, 
"i915_modeset", 0);
+       if (ret)
+               goto cleanup_vga_client_pw_domain_dmc;
+
+       ret = drmm_alloc_workqueue(&i915->drm, i915->display.wq.flip,
+                                  "i915_flip", WQ_HIGHPRI | WQ_UNBOUND,
+                                  WQ_UNBOUND_MAX_ACTIVE);
+       if (ret)
+               goto cleanup_vga_client_pw_domain_dmc;
 
        intel_mode_config_init(i915);
 
@@ -9004,9 +9012,6 @@ void intel_modeset_driver_remove_noirq(struct 
drm_i915_private *i915)
 
        intel_gmbus_teardown(i915);
 
-       destroy_workqueue(i915->display.wq.flip);
-       destroy_workqueue(i915->display.wq.modeset);
-
        intel_fbc_cleanup(i915);
 }
 
-- 
2.25.1