From: Stephane Grosjean <s.grosjean@xxxxxxxxxxxxxxx>
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@xxxxxxxxxxxxxxx
Cc: linux-stable <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Stephane Grosjean <s.grosjean@xxxxxxxxxxxxxxx>
Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
---
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:
--
2.30.2
