net: thunderbolt: Enable end-to-end flow control also in transmit

According to USB4 specification, if E2E flow control is disabled for
the Transmit Descriptor Ring, the Host Interface Adapter Layer shall
not require any credits to be available before transmitting a Tunneled
Packet from this Transmit Descriptor Ring, so e2e flow control should
be enabled in both directions.

Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Link: https://lore.kernel.org/20250624153805.GC2824380@black.fi.intel.com
Signed-off-by: zhangjianrong <zhangjianrong5@huawei.com>
Link: https://patch.msgid.link/20250628093813.647005-1-zhangjianrong5@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/thunderbolt/main.c b/drivers/net/thunderbolt/main.c
index f4c78275956622c2e46d927557655e5a3a8662fa..dcaa62377808c290fa3103347f6089c942f04057 100644 (file)
--- a/drivers/net/thunderbolt/main.c
+++ b/drivers/net/thunderbolt/main.c
@@ -924,8 +924,12 @@ static int tbnet_open(struct net_device *dev)
 
        netif_carrier_off(dev);
 
-       ring = tb_ring_alloc_tx(xd->tb->nhi, -1, TBNET_RING_SIZE,
-                               RING_FLAG_FRAME);
+       flags = RING_FLAG_FRAME;
+       /* Only enable full E2E if the other end supports it too */
+       if (tbnet_e2e && net->svc->prtcstns & TBNET_E2E)
+               flags |= RING_FLAG_E2E;
+
+       ring = tb_ring_alloc_tx(xd->tb->nhi, -1, TBNET_RING_SIZE, flags);
        if (!ring) {
                netdev_err(dev, "failed to allocate Tx ring\n");
                return -ENOMEM;
@@ -944,11 +948,6 @@ static int tbnet_open(struct net_device *dev)
        sof_mask = BIT(TBIP_PDF_FRAME_START);
        eof_mask = BIT(TBIP_PDF_FRAME_END);
 
-       flags = RING_FLAG_FRAME;
-       /* Only enable full E2E if the other end supports it too */
-       if (tbnet_e2e && net->svc->prtcstns & TBNET_E2E)
-               flags |= RING_FLAG_E2E;
-
        ring = tb_ring_alloc_rx(xd->tb->nhi, -1, TBNET_RING_SIZE, flags,
                                net->tx_ring.ring->hop, sof_mask,
                                eof_mask, tbnet_start_poll, net);