On 4.10.2019 23.30, Marc Kleine-Budde wrote: > From: Anssi Hannula <anssi.hannula@xxxxxxxxxx> > > 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@xxxxxxxxxx> > Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> > --- > Hello, > > taking up Anssi Hannula's work. > > changes since v1: > - xcan_err_interrupt(): use C99 initializers instead of memset() to > initialize struct can_frame cf. > - xcan_err_interrupt(): convert initialization of berr_reporting to use > "if". > > Please test. Thanks, I tried it on my HW and it seems to work like v1. > regards, > Marc > > drivers/net/can/xilinx_can.c | 89 +++++++++++++++++++----------------- > 1 file changed, 48 insertions(+), 41 deletions(-) [...] -- Anssi Hannula / Bitwise Oy +358 503803997
