If the command queue in the interface is flooded with messages which cannot
successfully be sent to the bus an initialization command would have to
wait to be executed.
Signed-off-by: Gerhard Uttenthaler <uttenthaler@xxxxxxxxxxxxxxxx>
---
drivers/net/can/usb/ems_usb.c | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)
diff --git a/drivers/net/can/usb/ems_usb.c b/drivers/net/can/usb/ems_usb.c
index e943cd07c5f7..a70bda631e4e 100644
--- a/drivers/net/can/usb/ems_usb.c
+++ b/drivers/net/can/usb/ems_usb.c
@@ -565,6 +565,21 @@ static int ems_usb_control_cmd(struct ems_usb *dev, u8 val)
return ems_usb_command_msg(dev, &cmd);
}
+/* Send a CPC_ClearCmdQueue command
+ */
+static int ems_usb_clear_cmd_queue(struct ems_usb *dev)
+{
+ struct ems_cpc_msg cmd = {
+ .type = CPC_CMD_TYPE_CLEAR_CMD_QUEUE,
+ .length = CPC_MSG_HEADER_LEN,
+ .msgid = 0,
+ .ts_sec = 0,
+ .ts_nsec = 0
+ };
+
+ return ems_usb_command_msg(dev, &cmd);
+}
+
/* Start interface
*/
static int ems_usb_start(struct ems_usb *dev)
@@ -897,6 +912,7 @@ static int ems_usb_set_bittiming(struct net_device *netdev)
struct ems_usb *dev = netdev_priv(netdev);
struct can_bittiming *bt = &dev->can.bittiming;
u8 btr0, btr1;
+ int err;
btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
@@ -904,6 +920,13 @@ static int ems_usb_set_bittiming(struct net_device *netdev)
if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
btr1 |= 0x80;
+ /* If the command queue in the device is full with incoming commands
+ * a reinitialization would not be possible before the queue is cleared.
+ */
+ err = ems_usb_clear_cmd_queue(dev);
+ if (err)
+ return err;
+
netdev_info(netdev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);
dev->active_params.msg.can_params.cc_params.sja1000.btr0 = btr0;
--
2.26.2
--
EMS Dr. Thomas Wuensche e.K.
Sonnenhang 3
85304 Ilmmuenster
HR Ingolstadt, HRA 170106
Phone: +49-8441-490260
Fax : +49-8441-81860
http://www.ems-wuensche.com
