Re: [PATCH net-next v3 3/9] ravb: Add aligned_tx to struct ravb_hw_info
From: Geert Uytterhoeven <geert@linux-m68k.org>
Date: 2021-08-23 09:14:37
Also in:
linux-renesas-soc
Hi Biju, On Wed, Aug 18, 2021 at 9:08 PM Biju Das [off-list ref] wrote:
R-Car Gen2 needs a 4byte aligned address for the transmission buffer, whereas R-Car Gen3 doesn't have any such restriction. Add aligned_tx to struct ravb_hw_info to select the driver to choose between aligned and unaligned tx buffers. Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com> Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Thanks for your patch, which is now commit 68ca3c923213b908 ("ravb:
Add aligned_tx to struct ravb_hw_info") in net-next.
quoted hunk ↗ jump to hunk
--- a/drivers/net/ethernet/renesas/ravb.h +++ b/drivers/net/ethernet/renesas/ravb.h@@ -990,6 +990,7 @@ enum ravb_chip_id { struct ravb_hw_info { enum ravb_chip_id chip_id; + unsigned aligned_tx: 1; }; struct ravb_private {diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c index b6554e5e13af..dbccf2cd89b2 100644 --- a/drivers/net/ethernet/renesas/ravb_main.c +++ b/drivers/net/ethernet/renesas/ravb_main.c@@ -1930,6 +1930,7 @@ static const struct ravb_hw_info ravb_gen3_hw_info = { static const struct ravb_hw_info ravb_gen2_hw_info = { .chip_id = RCAR_GEN2, + .aligned_tx = 1, }; static const struct of_device_id ravb_match_table[] = {@@ -2140,7 +2141,7 @@ 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->chip_id == RCAR_GEN2 ? + priv->num_tx_desc = info->aligned_tx ? NUM_TX_DESC_GEN2 : NUM_TX_DESC_GEN3;
At first look, this change does not seem to match the patch description.
Upon a deeper look, it is correct, as num_tx_desc is also used to
control alignment.
But now NUM_TX_DESC_GEN[23] no longer match their use.
Perhaps they should be renamed, or replaced by hardcoded values,
with a comment?
/*
* FIXME: Explain the relationship between alignment and number of buffers
*/
priv->num_tx_desc = info->aligned_tx ? 2 : 1;
/* Set function */
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds