The modeset lock protects the DDC code from concurrent modeset operations, which use the same registers. Move that code from the connector helpers into the DDC helpers .pre_xfer() and .post_xfer(). Both, .pre_xfer() and .post_xfer(), enclose the transfer of data blocks over the I2C channel in the internal I2C function bit_xfer(). Both calls are executed unconditionally if present. Invoking DDC transfers from any where within the driver now takes the lock. Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx> --- drivers/gpu/drm/ast/ast_ddc.c | 24 ++++++++++++++++++++++++ drivers/gpu/drm/ast/ast_mode.c | 30 ++++-------------------------- 2 files changed, 28 insertions(+), 26 deletions(-) diff --git a/drivers/gpu/drm/ast/ast_ddc.c b/drivers/gpu/drm/ast/ast_ddc.c index b84e656124f18..b7718084422f3 100644 --- a/drivers/gpu/drm/ast/ast_ddc.c +++ b/drivers/gpu/drm/ast/ast_ddc.c @@ -59,6 +59,28 @@ static void ast_ddc_algo_bit_data_setscl(void *data, int state) } } +static int ast_ddc_algo_bit_data_pre_xfer(struct i2c_adapter *adapter) +{ + struct ast_ddc *ddc = i2c_get_adapdata(adapter); + struct ast_device *ast = ddc->ast; + + /* + * Protect access to I/O registers from concurrent modesetting + * by acquiring the I/O-register lock. + */ + mutex_lock(&ast->modeset_lock); + + return 0; +} + +static void ast_ddc_algo_bit_data_post_xfer(struct i2c_adapter *adapter) +{ + struct ast_ddc *ddc = i2c_get_adapdata(adapter); + struct ast_device *ast = ddc->ast; + + mutex_unlock(&ast->modeset_lock); +} + static int ast_ddc_algo_bit_data_getsda(void *data) { struct ast_ddc *ddc = data; @@ -137,6 +159,8 @@ struct ast_ddc *ast_ddc_create(struct ast_device *ast) bit->setscl = ast_ddc_algo_bit_data_setscl; bit->getsda = ast_ddc_algo_bit_data_getsda; bit->getscl = ast_ddc_algo_bit_data_getscl; + bit->pre_xfer = ast_ddc_algo_bit_data_pre_xfer; + bit->post_xfer = ast_ddc_algo_bit_data_post_xfer; adapter->algo_data = bit; ret = i2c_bit_add_bus(adapter); diff --git a/drivers/gpu/drm/ast/ast_mode.c b/drivers/gpu/drm/ast/ast_mode.c index fc73d3b65b2a1..8766a0f2eb3c7 100644 --- a/drivers/gpu/drm/ast/ast_mode.c +++ b/drivers/gpu/drm/ast/ast_mode.c @@ -1346,30 +1346,19 @@ static int ast_crtc_init(struct drm_device *dev) static int ast_vga_connector_helper_get_modes(struct drm_connector *connector) { - struct drm_device *dev = connector->dev; - struct ast_device *ast = to_ast_device(dev); struct edid *edid; int count; - /* - * Protect access to I/O registers from concurrent modesetting - * by acquiring the I/O-register lock. - */ - mutex_lock(&ast->modeset_lock); - edid = drm_get_edid(connector, connector->ddc); if (!edid) - goto err_mutex_unlock; - - mutex_unlock(&ast->modeset_lock); + goto err_drm_get_edid; count = drm_add_edid_modes(connector, edid); kfree(edid); return count; -err_mutex_unlock: - mutex_unlock(&ast->modeset_lock); +err_drm_get_edid: drm_connector_update_edid_property(connector, NULL); return 0; } @@ -1444,30 +1433,19 @@ static int ast_vga_output_init(struct ast_device *ast) static int ast_sil164_connector_helper_get_modes(struct drm_connector *connector) { - struct drm_device *dev = connector->dev; - struct ast_device *ast = to_ast_device(dev); struct edid *edid; int count; - /* - * Protect access to I/O registers from concurrent modesetting - * by acquiring the I/O-register lock. - */ - mutex_lock(&ast->modeset_lock); - edid = drm_get_edid(connector, connector->ddc); if (!edid) - goto err_mutex_unlock; - - mutex_unlock(&ast->modeset_lock); + goto err_drm_get_edid; count = drm_add_edid_modes(connector, edid); kfree(edid); return count; -err_mutex_unlock: - mutex_unlock(&ast->modeset_lock); +err_drm_get_edid: drm_connector_update_edid_property(connector, NULL); return 0; } -- 2.44.0