[Intel-gfx] [PATCH] drm/i915: Cancel the modeset retry work during modeset cleanup

Thu Oct 26 01:20:04 UTC 2017

During modeset cleanup on driver unload we may have a pending
hotplug work. This needs to be cancel early during the teardown
so that it does not fire after we have freed the connector.
We do this after drm_kms_helper_poll_fini(dev) since this might
cause link retrain and before intel_fbdev_fini() since this tries to
free the connector.

If this is not done we may see something like:
DEBUG_LOCKS_WARN_ON(mutex_is_locked(lock))
 ------------[ cut here ]------------
 WARNING: CPU: 4 PID: 5010 at kernel/locking/mutex-debug.c:103 mutex_destroy+0x4e/0x60
 Modules linked in: i915(-) snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic snd_hda_codec snd_hwdep snd_hda_core snd_pcm vgem ax88179_178
+a usbnet mii x86_pkg_temp_thermal intel_powerclamp coretemp crct10dif_pclmul crc32_pclmul ghash_clmulni_intel e1000e ptp pps_core prime_numbers i2c_hid
+[last unloaded: snd_hda_intel]
 CPU: 4 PID: 5010 Comm: drv_module_relo Tainted: G     U          4.14.0-rc3-CI-CI_DRM_3186+ #1
 Hardware name: Intel Corporation CoffeeLake Client Platform/CoffeeLake S UDIMM RVP, BIOS CNLSFWX1.R00.X104.A03.1709140524 09/14/2017
 task: ffff8803c827aa40 task.stack: ffffc90000520000
 RIP: 0010:mutex_destroy+0x4e/0x60
 RSP: 0018:ffffc90000523d58 EFLAGS: 00010292
 RAX: 000000000000002a RBX: ffff88044fbef648 RCX: 0000000000000000
 RDX: 0000000080000001 RSI: 0000000000000001 RDI: ffffffff810f0cf0
 RBP: ffffc90000523d60 R08: 0000000000000001 R09: 0000000000000001
 R10: 000000000f21cb81 R11: 0000000000000000 R12: ffff88044f71efc8
 R13: ffffffffa02b3d20 R14: ffffffffa02b3d90 R15: ffff880459b29308
 FS:  00007f5df4d6e8c0(0000) GS:ffff88045d300000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 000055ec51f00a18 CR3: 0000000451782006 CR4: 00000000003606e0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 Call Trace:
  drm_fb_helper_fini+0xd9/0x130
  intel_fbdev_destroy+0x12/0x60 [i915]
  intel_fbdev_fini+0x28/0x30 [i915]
  intel_modeset_cleanup+0x45/0xa0 [i915]
  i915_driver_unload+0x92/0x180 [i915]
  i915_pci_remove+0x19/0x30 [i915]
  i915_driver_unload+0x92/0x180 [i915]
  i915_pci_remove+0x19/0x30 [i915]
  pci_device_remove+0x39/0xb0
  device_release_driver_internal+0x15d/0x220
  driver_detach+0x40/0x80
  bus_remove_driver+0x58/0xd0
  driver_unregister+0x2c/0x40
  pci_unregister_driver+0x36/0xb0
  i915_exit+0x1a/0x8b [i915]
  SyS_delete_module+0x18c/0x1e0
  entry_SYSCALL_64_fastpath+0x1c/0xb1
 RIP: 0033:0x7f5df3286287
 RSP: 002b:00007fff8e107cc8 EFLAGS: 00000246 ORIG_RAX: 00000000000000b0
 RAX: ffffffffffffffda RBX: ffffffff81493a03 RCX: 00007f5df3286287
 RDX: 0000000000000001 RSI: 0000000000000800 RDI: 0000564c7be02e48
 RBP: ffffc90000523f88 R08: 0000000000000000 R09: 0000000000000080
 R10: 00007f5df4d6e8c0 R11: 0000000000000246 R12: 0000000000000000
 R13: 00007fff8e107eb0 R14: 0000000000000000 R15: 0000000000000000

Suggested-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
Suggested-by: Chris Wilson <chris at chris-wilson.co.uk>
Fixes: 9301397a63b3 ("drm/i915: Implement Link Rate fallback on Link training failure")
Cc: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Tony Cheng <tony.cheng at amd.com>
Cc: Harry Wentland <Harry.wentland at amd.com>
Cc: Jani Nikula <jani.nikula at linux.intel.com>
Cc: Daniel Vetter <daniel.vetter at intel.com>
Cc: Ville Syrjala <ville.syrjala at linux.intel.com>
Cc: Manasi Navare <manasi.d.navare at intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
Signed-off-by: Manasi Navare <manasi.d.navare at intel.com>
---
 drivers/gpu/drm/i915/i915_drv.h      |  1 +
 drivers/gpu/drm/i915/intel_display.c | 16 ++++++++++++++++
 2 files changed, 17 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 366ba74..f81b073 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -4114,6 +4114,7 @@ extern void intel_modeset_gem_init(struct drm_device *dev);
 extern void intel_modeset_cleanup(struct drm_device *dev);
 extern int intel_connector_register(struct drm_connector *);
 extern void intel_connector_unregister(struct drm_connector *);
+extern void intel_connector_work_fn_cleanup(struct drm_device *dev);
 extern int intel_modeset_vga_set_state(struct drm_i915_private *dev_priv,
 				       bool state);
 extern void intel_display_resume(struct drm_device *dev);
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 0e493a1..44158ff 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -15200,6 +15200,19 @@ void intel_connector_unregister(struct drm_connector *connector)
 	intel_panel_destroy_backlight(connector);
 }
 
+void intel_connector_work_fn_cleanup(struct drm_device *dev)
+{
+	struct intel_connector *connector;
+	struct drm_connector_list_iter conn_iter;
+
+	drm_connector_list_iter_begin(dev, &conn_iter);
+	for_each_intel_connector_iter(connector, &conn_iter) {
+		if (connector->modeset_retry_work.func)
+			cancel_work_sync(&connector->modeset_retry_work);
+	}
+	drm_connector_list_iter_end(&conn_iter);
+}
+
 void intel_modeset_cleanup(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = to_i915(dev);
@@ -15222,6 +15235,9 @@ void intel_modeset_cleanup(struct drm_device *dev)
 	 */
 	drm_kms_helper_poll_fini(dev);
 
+	/* Cancel pending modeset retry work in intel_connector */
+	intel_connector_work_fn_cleanup(dev);
+
 	/* poll work can call into fbdev, hence clean that up afterwards */
 	intel_fbdev_fini(dev_priv);
 
-- 
2.1.4

