91e9f2c0e7
Userspace can signal with CAN_CTRLMODE_BERR_REPORTING whether they need reporting of bus errors (CAN_ERR_BUSERROR) or not. However, xilinx_can driver currently always sends CAN_ERR_BUSERROR frames to userspace on bus errors. To improve performance on error conditions when bus error reporting is not needed, avoid sending CAN_ERR_BUSERROR frames unless requested via CAN_CTRLMODE_BERR_REPORTING. The error interrupt is still kept enabled as there is no dedicated state transition interrupt, but just disabling error frame submission still yields a significant performance improvement. In a simple test with continuous bus errors and no userspace programs reading/writing CAN I saw system CPU load reduced by 1/3. Tested on a ZynqMP board with CAN-FD v1.0. Signed-off-by: Anssi Hannula <anssi.hannula@bitwise.fi> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>