Subject: [PATCH 06/14] can: m_can: Add rx coalescing ethtool support

Add the possibility to set coalescing parameters with ethtool.

rx-frames-irq and rx-usecs-irq can only be set and unset together as the
implemented mechanism would not work otherwise. rx-frames-irq can't be
greater than the RX FIFO size.

Also all values can only be changed if the chip is not active.

Polling is excluded from irq coalescing support.

Signed-off-by: Markus Schneider-Pargmann <[email protected]>
---
drivers/net/can/m_can/m_can.c | 55 ++++++++++++++++++++++++++++++++++-
1 file changed, 54 insertions(+), 1 deletion(-)

diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
index 9b3e8e09f3aa..6dad1f569f82 100644
--- a/drivers/net/can/m_can/m_can.c
+++ b/drivers/net/can/m_can/m_can.c
@@ -1977,7 +1977,57 @@ static const struct net_device_ops m_can_netdev_ops = {
.ndo_change_mtu = can_change_mtu,
};

+static int m_can_get_coalesce(struct net_device *dev,
+ struct ethtool_coalesce *ec,
+ struct kernel_ethtool_coalesce *kec,
+ struct netlink_ext_ack *ext_ack)
+{
+ struct m_can_classdev *cdev = netdev_priv(dev);
+
+ ec->rx_max_coalesced_frames_irq = cdev->rx_max_coalesced_frames_irq;
+ ec->rx_coalesce_usecs_irq = cdev->rx_coalesce_usecs_irq;
+
+ return 0;
+}
+
+static int m_can_set_coalesce(struct net_device *dev,
+ struct ethtool_coalesce *ec,
+ struct kernel_ethtool_coalesce *kec,
+ struct netlink_ext_ack *ext_ack)
+{
+ struct m_can_classdev *cdev = netdev_priv(dev);
+
+ if (cdev->can.state != CAN_STATE_STOPPED) {
+ netdev_err(dev, "Device is in use, please shut it down first\n");
+ return -EBUSY;
+ }
+
+ if (ec->rx_max_coalesced_frames_irq > cdev->mcfg[MRAM_RXF0].num) {
+ netdev_err(dev, "rx-frames-irq %u greater than the RX FIFO %u\n",
+ ec->rx_max_coalesced_frames_irq,
+ cdev->mcfg[MRAM_RXF0].num);
+ return -EINVAL;
+ }
+ if ((ec->rx_max_coalesced_frames_irq == 0) != (ec->rx_coalesce_usecs_irq == 0)) {
+ netdev_err(dev, "rx-frames-irq and rx-usecs-irq can only be set together\n");
+ return -EINVAL;
+ }
+
+ cdev->rx_max_coalesced_frames_irq = ec->rx_max_coalesced_frames_irq;
+ cdev->rx_coalesce_usecs_irq = ec->rx_coalesce_usecs_irq;
+
+ return 0;
+}
+
static const struct ethtool_ops m_can_ethtool_ops = {
+ .supported_coalesce_params = ETHTOOL_COALESCE_RX_USECS_IRQ |
+ ETHTOOL_COALESCE_RX_MAX_FRAMES_IRQ,
+ .get_ts_info = ethtool_op_get_ts_info,
+ .get_coalesce = m_can_get_coalesce,
+ .set_coalesce = m_can_set_coalesce,
+};
+
+static const struct ethtool_ops m_can_ethtool_ops_polling = {
.get_ts_info = ethtool_op_get_ts_info,
};

@@ -1985,7 +2035,10 @@ static int register_m_can_dev(struct net_device *dev)
{
dev->flags |= IFF_ECHO; /* we support local echo */
dev->netdev_ops = &m_can_netdev_ops;
- dev->ethtool_ops = &m_can_ethtool_ops;
+ if (dev->irq)
+ dev->ethtool_ops = &m_can_ethtool_ops;
+ else
+ dev->ethtool_ops = &m_can_ethtool_ops_polling;

return register_candev(dev);
}
--
2.43.0