From: Ville Syrjälä Date: Mon, 7 Mar 2016 15:56:58 +0000 (+0200) Subject: drm/i915: Protect force_bit with gmbus_mutex X-Git-Tag: v4.7-rc1~77^2~37^2~138 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=ade754ec1143caeada0bae01e4c3ea3188497bfd;p=karo-tx-linux.git drm/i915: Protect force_bit with gmbus_mutex Extend the protection of gmbus_mutex around the force_bit RMW in intel_gmbus_force_bit(), in case someone gets the idea of calling it from a separate thread while there's other stuff happening on the same bus. Signed-off-by: Ville Syrjälä Link: http://patchwork.freedesktop.org/patch/msgid/1457366220-29409-3-git-send-email-ville.syrjala@linux.intel.com Reviewed-by: Jani Nikula --- diff --git a/drivers/gpu/drm/i915/intel_i2c.c b/drivers/gpu/drm/i915/intel_i2c.c index 6dbe73ecb41a..c5d5010284e2 100644 --- a/drivers/gpu/drm/i915/intel_i2c.c +++ b/drivers/gpu/drm/i915/intel_i2c.c @@ -718,11 +718,16 @@ void intel_gmbus_set_speed(struct i2c_adapter *adapter, int speed) void intel_gmbus_force_bit(struct i2c_adapter *adapter, bool force_bit) { struct intel_gmbus *bus = to_intel_gmbus(adapter); + struct drm_i915_private *dev_priv = bus->dev_priv; + + mutex_lock(&dev_priv->gmbus_mutex); bus->force_bit += force_bit ? 1 : -1; DRM_DEBUG_KMS("%sabling bit-banging on %s. force bit now %d\n", force_bit ? "en" : "dis", adapter->name, bus->force_bit); + + mutex_unlock(&dev_priv->gmbus_mutex); } void intel_teardown_gmbus(struct drm_device *dev)