From 4f71d0cb76339a10fd445b0b281acc45c71b6271 Mon Sep 17 00:00:00 2001 From: Dave Airlie Date: Wed, 4 Jun 2014 16:02:28 +1000 Subject: drm/dp: add a hw mutex around the transfer functions. (v2) This should avoid races between connector probing and HPD irqs in the future, currently mode_config.mutex blocks this possibility. Reviewed-by: Daniel Vetter Signed-off-by: Dave Airlie --- drivers/gpu/drm/drm_dp_helper.c | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-) (limited to 'drivers/gpu/drm/drm_dp_helper.c') diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index 494219c..08e33b8 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -216,7 +216,7 @@ i2c_dp_aux_prepare_bus(struct i2c_adapter *adapter) * * IMPORTANT: * This interface is deprecated, please switch to the new dp aux helpers and - * drm_dp_aux_register_i2c_bus(). + * drm_dp_aux_register(). */ int i2c_dp_aux_add_bus(struct i2c_adapter *adapter) @@ -382,7 +382,10 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, * transactions. */ for (retry = 0; retry < 7; retry++) { + + mutex_lock(&aux->hw_mutex); err = aux->transfer(aux, &msg); + mutex_unlock(&aux->hw_mutex); if (err < 0) { if (err == -EBUSY) continue; @@ -596,7 +599,9 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) * before giving up the AUX transaction. */ for (retry = 0; retry < 7; retry++) { + mutex_lock(&aux->hw_mutex); err = aux->transfer(aux, msg); + mutex_unlock(&aux->hw_mutex); if (err < 0) { if (err == -EBUSY) continue; @@ -729,13 +734,15 @@ static const struct i2c_algorithm drm_dp_i2c_algo = { }; /** - * drm_dp_aux_register_i2c_bus() - register an I2C adapter for I2C-over-AUX + * drm_dp_aux_register() - initialise and register aux channel * @aux: DisplayPort AUX channel * * Returns 0 on success or a negative error code on failure. */ -int drm_dp_aux_register_i2c_bus(struct drm_dp_aux *aux) +int drm_dp_aux_register(struct drm_dp_aux *aux) { + mutex_init(&aux->hw_mutex); + aux->ddc.algo = &drm_dp_i2c_algo; aux->ddc.algo_data = aux; aux->ddc.retries = 3; @@ -750,14 +757,14 @@ int drm_dp_aux_register_i2c_bus(struct drm_dp_aux *aux) return i2c_add_adapter(&aux->ddc); } -EXPORT_SYMBOL(drm_dp_aux_register_i2c_bus); +EXPORT_SYMBOL(drm_dp_aux_register); /** - * drm_dp_aux_unregister_i2c_bus() - unregister an I2C-over-AUX adapter + * drm_dp_aux_unregister() - unregister an AUX adapter * @aux: DisplayPort AUX channel */ -void drm_dp_aux_unregister_i2c_bus(struct drm_dp_aux *aux) +void drm_dp_aux_unregister(struct drm_dp_aux *aux) { i2c_del_adapter(&aux->ddc); } -EXPORT_SYMBOL(drm_dp_aux_unregister_i2c_bus); +EXPORT_SYMBOL(drm_dp_aux_unregister); -- cgit v1.1