From: Stephane Grosjean s.grosjean@peak-system.com

This patch fixes an incorrect way of reading error counters in messages received for this purpose from the PCAN-USB interface. These messages inform about the increase or decrease of the error counters, whose values are placed in bytes 1 and 2 of the message data (not 0 and 1).

Fixes: ea8b33bde76c ("can: pcan_usb: add support of rxerr/txerr counters") Link: https://lore.kernel.org/r/20210625130931.27438-4-s.grosjean@peak-system.com Cc: linux-stable stable@vger.kernel.org Signed-off-by: Stephane Grosjean s.grosjean@peak-system.com Signed-off-by: Marc Kleine-Budde mkl@pengutronix.de --- drivers/net/can/usb/peak_usb/pcan_usb.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/net/can/usb/peak_usb/pcan_usb.c b/drivers/net/can/usb/peak_usb/pcan_usb.c index 1d6f77252f01..899a3d21b77f 100644 --- a/drivers/net/can/usb/peak_usb/pcan_usb.c +++ b/drivers/net/can/usb/peak_usb/pcan_usb.c @@ -117,7 +117,8 @@ #define PCAN_USB_BERR_MASK (PCAN_USB_ERR_RXERR | PCAN_USB_ERR_TXERR)

/* identify bus event packets with rx/tx error counters */ -#define PCAN_USB_ERR_CNT 0x80 +#define PCAN_USB_ERR_CNT_DEC 0x00 /* counters are decreasing */ +#define PCAN_USB_ERR_CNT_INC 0x80 /* counters are increasing */

/* private to PCAN-USB adapter */ struct pcan_usb { @@ -608,11 +609,12 @@ static int pcan_usb_handle_bus_evt(struct pcan_usb_msg_context *mc, u8 ir)

/* acccording to the content of the packet */ switch (ir) { - case PCAN_USB_ERR_CNT: + case PCAN_USB_ERR_CNT_DEC: + case PCAN_USB_ERR_CNT_INC:

/* save rx/tx error counters from in the device context */ - pdev->bec.rxerr = mc->ptr[0]; - pdev->bec.txerr = mc->ptr[1]; + pdev->bec.rxerr = mc->ptr[1]; + pdev->bec.txerr = mc->ptr[2]; break;

default: