Re: [PATCH net-next 01/13] ravb: Remove the macros NUM_TX_DESC_GEN[23]
From: Sergey Shtylyov <hidden>
Date: 2021-08-25 14:30:24
Also in:
linux-renesas-soc
Hello! On 8/25/21 10:01 AM, Biju Das wrote:
For addressing 4 bytes alignment restriction on transmission buffer for R-Car Gen2 we use 2 descriptors whereas it is a single descriptor for other cases. Replace the macros NUM_TX_DESC_GEN[23] with magic number and add a comment to explain it. Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com> Suggested-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
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quoted hunk ↗ jump to hunk
diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c index 02842b980a7f..073e690ab830 100644 --- a/drivers/net/ethernet/renesas/ravb_main.c +++ b/drivers/net/ethernet/renesas/ravb_main.c@@ -2160,8 +2160,12 @@ static int ravb_probe(struct platform_device *pdev) ndev->max_mtu = 2048 - (ETH_HLEN + VLAN_HLEN + ETH_FCS_LEN); ndev->min_mtu = ETH_MIN_MTU; - priv->num_tx_desc = info->aligned_tx ? - NUM_TX_DESC_GEN2 : NUM_TX_DESC_GEN3; + /* FIXME: R-Car Gen2 has 4byte alignment restriction for tx buffer
Mhm, what are you going to fix here?
+ * Use two descriptor to handle such situation. First descriptor to + * handle aligned data buffer and second descriptor to handle the + * overflow data because of alignment. + */ + priv->num_tx_desc = info->aligned_tx ? 2 : 1; /* Set function */ ndev->netdev_ops = &ravb_netdev_ops;
Other than that: Reviewed-by: Sergey Shtylyov <redacted> [...] MBR, Sergey