can: rockchip_canfd: prepare to use full TX-FIFO depth

So far the TX-FIFO is only used with a depth of 1, although the
hardware offers a depth of 2.

The workaround for the chips that are affected by erratum 6, i.e. EFF
frames may be send as standard frames, is to re-send the EFF frame.
This means the driver cannot queue the next frame for sending, as long
ad the EFF frame has not been successfully send out.

Introduce rkcanfd_get_effective_tx_free() that returns "0" space in
the TX-FIFO if an EFF frame is pending and the actual free space in
the TX-FIFO otherwise. Then replace rkcanfd_get_tx_free() with
rkcanfd_get_effective_tx_free() everywhere.

Tested-by: Alibek Omarov <a1ba.omarov@gmail.com>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patch.msgid.link/20240904-rockchip-canfd-v5-16-8ae22bcb27cc@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

diff --git a/drivers/net/can/rockchip/rockchip_canfd-rx.c b/drivers/net/can/rockchip/rockchip_canfd-rx.c
index 9f72483dab18806a4b7da03e019025b780ce4af0..bacef5e5dc395b4ead9ff5c7fe5921b6d60b634d 100644 (file)
--- a/drivers/net/can/rockchip/rockchip_canfd-rx.c
+++ b/drivers/net/can/rockchip/rockchip_canfd-rx.c
@@ -124,7 +124,7 @@ static int rkcanfd_rxstx_filter(struct rkcanfd_priv *priv,
 
                WRITE_ONCE(priv->tx_tail, priv->tx_tail + 1);
                netif_subqueue_completed_wake(priv->ndev, 0, 1, frame_len,
-                                             rkcanfd_get_tx_free(priv),
+                                             rkcanfd_get_effective_tx_free(priv),
                                              RKCANFD_TX_START_THRESHOLD);
 
                *tx_done = true;

diff --git a/drivers/net/can/rockchip/rockchip_canfd-tx.c b/drivers/net/can/rockchip/rockchip_canfd-tx.c
index f8e74e814b3b630c9865a7269dd6d1a844ef259c..d10da548ba714e2d3e222202ded31dedaafb7d97 100644 (file)
--- a/drivers/net/can/rockchip/rockchip_canfd-tx.c
+++ b/drivers/net/can/rockchip/rockchip_canfd-tx.c
@@ -8,6 +8,40 @@
 
 #include "rockchip_canfd.h"
 
+static bool rkcanfd_tx_tail_is_eff(const struct rkcanfd_priv *priv)
+{
+       const struct canfd_frame *cfd;
+       const struct sk_buff *skb;
+       unsigned int tx_tail;
+
+       if (!rkcanfd_get_tx_pending(priv))
+               return false;
+
+       tx_tail = rkcanfd_get_tx_tail(priv);
+       skb = priv->can.echo_skb[tx_tail];
+       if (!skb) {
+               netdev_err(priv->ndev,
+                          "%s: echo_skb[%u]=NULL tx_head=0x%08x tx_tail=0x%08x\n",
+                          __func__, tx_tail,
+                          priv->tx_head, priv->tx_tail);
+
+               return false;
+       }
+
+       cfd = (struct canfd_frame *)skb->data;
+
+       return cfd->can_id & CAN_EFF_FLAG;
+}
+
+unsigned int rkcanfd_get_effective_tx_free(const struct rkcanfd_priv *priv)
+{
+       if (priv->devtype_data.quirks & RKCANFD_QUIRK_RK3568_ERRATUM_6 &&
+           rkcanfd_tx_tail_is_eff(priv))
+               return 0;
+
+       return rkcanfd_get_tx_free(priv);
+}
+
 static void rkcanfd_start_xmit_write_cmd(const struct rkcanfd_priv *priv,
                                         const u32 reg_cmd)
 {
@@ -42,7 +76,7 @@ int rkcanfd_start_xmit(struct sk_buff *skb, struct net_device *ndev)
                return NETDEV_TX_OK;
 
        if (!netif_subqueue_maybe_stop(priv->ndev, 0,
-                                      rkcanfd_get_tx_free(priv),
+                                      rkcanfd_get_effective_tx_free(priv),
                                       RKCANFD_TX_STOP_THRESHOLD,
                                       RKCANFD_TX_START_THRESHOLD)) {
                if (net_ratelimit())
@@ -99,7 +133,7 @@ int rkcanfd_start_xmit(struct sk_buff *skb, struct net_device *ndev)
        rkcanfd_start_xmit_write_cmd(priv, reg_cmd);
 
        netif_subqueue_maybe_stop(priv->ndev, 0,
-                                 rkcanfd_get_tx_free(priv),
+                                 rkcanfd_get_effective_tx_free(priv),
                                  RKCANFD_TX_STOP_THRESHOLD,
                                  RKCANFD_TX_START_THRESHOLD);
 

diff --git a/drivers/net/can/rockchip/rockchip_canfd.h b/drivers/net/can/rockchip/rockchip_canfd.h
index f24a1d18be66f24bae798a680fae4c3f2fc66c52..37d90400429fec8df854f29d29bfe85c17fc305d 100644 (file)
--- a/drivers/net/can/rockchip/rockchip_canfd.h
+++ b/drivers/net/can/rockchip/rockchip_canfd.h
@@ -533,6 +533,7 @@ int rkcanfd_handle_rx_int(struct rkcanfd_priv *priv);
 
 void rkcanfd_timestamp_init(struct rkcanfd_priv *priv);
 
+unsigned int rkcanfd_get_effective_tx_free(const struct rkcanfd_priv *priv);
 void rkcanfd_xmit_retry(struct rkcanfd_priv *priv);
 int rkcanfd_start_xmit(struct sk_buff *skb, struct net_device *ndev);
 void rkcanfd_handle_tx_done_one(struct rkcanfd_priv *priv, const u32 ts,