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authorKeith Packard <keithp@keithp.com>2011-07-25 10:04:56 -0700
committerKeith Packard <keithp@keithp.com>2011-07-25 14:54:22 -0700
commita65e34c79c88895766ab1f8a5afa451eed26622b (patch)
tree02ebb8818c40f44c248b5c322ee9c301af984dc6 /drivers/gpu
parenta2cab1b24a4ea75a68fa21bfb7d5b1a45121583c (diff)
downloadop-kernel-dev-a65e34c79c88895766ab1f8a5afa451eed26622b.zip
op-kernel-dev-a65e34c79c88895766ab1f8a5afa451eed26622b.tar.gz
drm/i915: Hold mode_config->mutex during hotplug processing
Hotplug detection is a mode setting operation and must hold the struct_mutex or risk colliding with other mode setting operations. In particular, the display port hotplug function attempts to re-train the link if the monitor is supposed to be running when plugged back in. If that happens while mode setting is underway, the link will get scrambled, leaving it in an inconsistent state. This is a special case -- usually the driver mode setting entry points are covered by the upper level DRM code, but in this case the function is invoked as a work function not under the control of DRM. Signed-off-by: Keith Packard <keithp@keithp.com> Cc: stable@kernel.org Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Diffstat (limited to 'drivers/gpu')
-rw-r--r--drivers/gpu/drm/i915/i915_irq.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 3b03f85..9da2a2c 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -306,6 +306,7 @@ static void i915_hotplug_work_func(struct work_struct *work)
struct drm_mode_config *mode_config = &dev->mode_config;
struct intel_encoder *encoder;
+ mutex_lock(&mode_config->mutex);
DRM_DEBUG_KMS("running encoder hotplug functions\n");
list_for_each_entry(encoder, &mode_config->encoder_list, base.head)
@@ -314,6 +315,8 @@ static void i915_hotplug_work_func(struct work_struct *work)
/* Just fire off a uevent and let userspace tell us what to do */
drm_helper_hpd_irq_event(dev);
+
+ mutex_unlock(&mode_config->mutex);
}
static void i915_handle_rps_change(struct drm_device *dev)
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