patches.baytrail/0960-drm-i915-destroy-connector-sysfs-files-earlier.patch

From 53a179a27894eaff518f8de54be07dcb47b0c9ff Mon Sep 17 00:00:00 2001
From: Paulo Zanoni <paulo.r.zanoni@intel.com>
Date: Thu, 26 Sep 2013 20:05:59 -0300
Subject: 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>
(cherry picked from commit d9255d57147e1dbcebdf6670409c2fa0ac3609e6)
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
---
 drivers/gpu/drm/i915/intel_crt.c     |    1 -
 drivers/gpu/drm/i915/intel_display.c |    5 +++++
 drivers/gpu/drm/i915/intel_dp.c      |    1 -
 drivers/gpu/drm/i915/intel_dsi.c     |    1 -
 drivers/gpu/drm/i915/intel_dvo.c     |    1 -
 drivers/gpu/drm/i915/intel_hdmi.c    |    1 -
 drivers/gpu/drm/i915/intel_lvds.c    |    1 -
 drivers/gpu/drm/i915/intel_sdvo.c    |    7 +++++--
 drivers/gpu/drm/i915/intel_tv.c      |    1 -
 9 files changed, 10 insertions(+), 9 deletions(-)

--- a/drivers/gpu/drm/i915/intel_crt.c
+++ b/drivers/gpu/drm/i915/intel_crt.c
@@ -678,7 +678,6 @@ intel_crt_detect(struct drm_connector *c
 
 static void intel_crt_destroy(struct drm_connector *connector)
 {
-	drm_sysfs_connector_remove(connector);
 	drm_connector_cleanup(connector);
 	kfree(connector);
 }
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -10731,6 +10731,7 @@ void intel_modeset_cleanup(struct drm_de
 {
 	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.
@@ -10773,6 +10774,10 @@ void intel_modeset_cleanup(struct drm_de
 	/* 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);
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -3213,7 +3213,6 @@ intel_dp_connector_destroy(struct drm_co
 	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);
 }
--- 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
 
 	DRM_DEBUG_KMS("\n");
 	intel_panel_fini(&intel_connector->panel);
-	drm_sysfs_connector_remove(connector);
 	drm_connector_cleanup(connector);
 	kfree(connector);
 }
--- 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 dr
 
 static void intel_dvo_destroy(struct drm_connector *connector)
 {
-	drm_sysfs_connector_remove(connector);
 	drm_connector_cleanup(connector);
 	kfree(connector);
 }
--- 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(stru
 
 static void intel_hdmi_destroy(struct drm_connector *connector)
 {
-	drm_sysfs_connector_remove(connector);
 	drm_connector_cleanup(connector);
 	kfree(connector);
 }
--- 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 dr
 
 	intel_panel_fini(&lvds_connector->base.panel);
 
-	drm_sysfs_connector_remove(connector);
 	drm_connector_cleanup(connector);
 	kfree(connector);
 }
--- 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 dr
 				     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 *in
 	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 *
 	return true;
 
 err:
+	drm_sysfs_connector_remove(connector);
 	intel_sdvo_destroy(connector);
 	return false;
 }
@@ -2624,8 +2625,10 @@ static void intel_sdvo_output_cleanup(st
 
 	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);
+		}
 	}
 }
 
--- a/drivers/gpu/drm/i915/intel_tv.c
+++ b/drivers/gpu/drm/i915/intel_tv.c
@@ -1437,7 +1437,6 @@ intel_tv_get_modes(struct drm_connector
 static void
 intel_tv_destroy(struct drm_connector *connector)
 {
-	drm_sysfs_connector_remove(connector);
 	drm_connector_cleanup(connector);
 	kfree(connector);
 }