drm/i915: destroy connector sysfs files earlier

For some reason, every single time I try to run module_reload
something tries to read the connector sysfs files. This happens
after we destroy the encoders and before we destroy the connectors, so
when the sysfs read triggers the connector detect() function,
intel_conector->encoder points to memory that was already freed.

The bad backtrace is just:
    [<ffffffff8163ca9a>] dump_stack+0x54/0x74
    [<ffffffffa00c2c8e>] intel_dp_detect+0x1e/0x4b0 [i915]
    [<ffffffffa001913d>] status_show+0x3d/0x80 [drm]
    [<ffffffff813d5340>] dev_attr_show+0x20/0x60
    [<ffffffff81221f50>] ? sysfs_read_file+0x80/0x1b0
    [<ffffffff81221f79>] sysfs_read_file+0xa9/0x1b0
    [<ffffffff811aaf1e>] vfs_read+0x9e/0x170
    [<ffffffff811aba4c>] SyS_read+0x4c/0xa0
    [<ffffffff8164e392>] system_call_fastpath+0x16/0x1b

But if you add tons of memory checking debug options to your Kernel
you'll also see:
 - general protection fault: 0000
 - BUG kmalloc-4096 (Tainted: G      D W   ): Poison overwritten
 - INFO: Allocated in intel_ddi_init+0x65/0x270 [i915]
 - INFO: Freed in intel_dp_encoder_destroy+0x69/0xb0 [i915]
Among a bunch of other error messages.

So this commit just destroys the sysfs files before both the encoder
and connectors are freed.

Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

9 files changed, 10 insertions, 9 deletions

diff --git a/drivers/gpu/drm/i915/intel_crt.c b/drivers/gpu/drm/i915/intel_crt.c
index 0263629332d0..942b9acb0d8e 100644
--- a/drivers/gpu/drm/i915/intel_crt.c
+++ b/drivers/gpu/drm/i915/intel_crt.c
@@ -677,7 +677,6 @@ intel_crt_detect(struct drm_connector *connector, bool force)
 
 static void intel_crt_destroy(struct drm_connector *connector)
 {
-	drm_sysfs_connector_remove(connector);
 	drm_connector_cleanup(connector);
 	kfree(connector);
 }
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 76870f0ffa7a..29b938779812 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -10727,6 +10727,7 @@ void intel_modeset_cleanup(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct drm_crtc *crtc;
+	struct drm_connector *connector;
 
 	/*
 	 * Interrupts and polling as the first thing to avoid creating havoc.
@@ -10769,6 +10770,10 @@ void intel_modeset_cleanup(struct drm_device *dev)
 	/* destroy backlight, if any, before the connectors */
 	intel_panel_destroy_backlight(dev);
 
+	/* destroy the sysfs files before encoders/connectors */
+	list_for_each_entry(connector, &dev->mode_config.connector_list, head)
+		drm_sysfs_connector_remove(connector);
+
 	drm_mode_config_cleanup(dev);
 
 	intel_cleanup_overlay(dev);
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 2d790d019725..5614365465c9 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -3189,7 +3189,6 @@ intel_dp_connector_destroy(struct drm_connector *connector)
 	if (connector->connector_type == DRM_MODE_CONNECTOR_eDP)
 		intel_panel_fini(&intel_connector->panel);
 
-	drm_sysfs_connector_remove(connector);
 	drm_connector_cleanup(connector);
 	kfree(connector);
 }
diff --git a/drivers/gpu/drm/i915/intel_dsi.c b/drivers/gpu/drm/i915/intel_dsi.c
index 674fd4989b45..9a2fdd2a7e34 100644
--- a/drivers/gpu/drm/i915/intel_dsi.c
+++ b/drivers/gpu/drm/i915/intel_dsi.c
@@ -504,7 +504,6 @@ static void intel_dsi_destroy(struct drm_connector *connector)
 
 	DRM_DEBUG_KMS("\n");
 	intel_panel_fini(&intel_connector->panel);
-	drm_sysfs_connector_remove(connector);
 	drm_connector_cleanup(connector);
 	kfree(connector);
 }
diff --git a/drivers/gpu/drm/i915/intel_dvo.c b/drivers/gpu/drm/i915/intel_dvo.c
index 91287d1d3059..1b64145c669a 100644
--- a/drivers/gpu/drm/i915/intel_dvo.c
+++ b/drivers/gpu/drm/i915/intel_dvo.c
@@ -367,7 +367,6 @@ static int intel_dvo_get_modes(struct drm_connector *connector)
 
 static void intel_dvo_destroy(struct drm_connector *connector)
 {
-	drm_sysfs_connector_remove(connector);
 	drm_connector_cleanup(connector);
 	kfree(connector);
 }
diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
index 6004f9c549aa..4f4d346db8f0 100644
--- a/drivers/gpu/drm/i915/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/intel_hdmi.c
@@ -1181,7 +1181,6 @@ static void intel_hdmi_post_disable(struct intel_encoder *encoder)
 
 static void intel_hdmi_destroy(struct drm_connector *connector)
 {
-	drm_sysfs_connector_remove(connector);
 	drm_connector_cleanup(connector);
 	kfree(connector);
 }
diff --git a/drivers/gpu/drm/i915/intel_lvds.c b/drivers/gpu/drm/i915/intel_lvds.c
index fb3f8efcc6e2..ae0c843dd263 100644
--- a/drivers/gpu/drm/i915/intel_lvds.c
+++ b/drivers/gpu/drm/i915/intel_lvds.c
@@ -474,7 +474,6 @@ static void intel_lvds_destroy(struct drm_connector *connector)
 
 	intel_panel_fini(&lvds_connector->base.panel);
 
-	drm_sysfs_connector_remove(connector);
 	drm_connector_cleanup(connector);
 	kfree(connector);
 }
diff --git a/drivers/gpu/drm/i915/intel_sdvo.c b/drivers/gpu/drm/i915/intel_sdvo.c
index 5e59d64cfd95..a583e8f718a7 100644
--- a/drivers/gpu/drm/i915/intel_sdvo.c
+++ b/drivers/gpu/drm/i915/intel_sdvo.c
@@ -2009,7 +2009,6 @@ static void intel_sdvo_destroy(struct drm_connector *connector)
 				     intel_sdvo_connector->tv_format);
 
 	intel_sdvo_destroy_enhance_property(connector);
-	drm_sysfs_connector_remove(connector);
 	drm_connector_cleanup(connector);
 	kfree(intel_sdvo_connector);
 }
@@ -2482,6 +2481,7 @@ intel_sdvo_tv_init(struct intel_sdvo *intel_sdvo, int type)
 	return true;
 
 err:
+	drm_sysfs_connector_remove(connector);
 	intel_sdvo_destroy(connector);
 	return false;
 }
@@ -2553,6 +2553,7 @@ intel_sdvo_lvds_init(struct intel_sdvo *intel_sdvo, int device)
 	return true;
 
 err:
+	drm_sysfs_connector_remove(connector);
 	intel_sdvo_destroy(connector);
 	return false;
 }
@@ -2624,8 +2625,10 @@ static void intel_sdvo_output_cleanup(struct intel_sdvo *intel_sdvo)
 
 	list_for_each_entry_safe(connector, tmp,
 				 &dev->mode_config.connector_list, head) {
-		if (intel_attached_encoder(connector) == &intel_sdvo->base)
+		if (intel_attached_encoder(connector) == &intel_sdvo->base) {
+			drm_sysfs_connector_remove(connector);
 			intel_sdvo_destroy(connector);
+		}
 	}
 }
 
diff --git a/drivers/gpu/drm/i915/intel_tv.c b/drivers/gpu/drm/i915/intel_tv.c
index 75925a1ab351..92895f92a738 100644
--- a/drivers/gpu/drm/i915/intel_tv.c
+++ b/drivers/gpu/drm/i915/intel_tv.c
@@ -1433,7 +1433,6 @@ intel_tv_get_modes(struct drm_connector *connector)
 static void
 intel_tv_destroy(struct drm_connector *connector)
 {
-	drm_sysfs_connector_remove(connector);
 	drm_connector_cleanup(connector);
 	kfree(connector);
 }