diff mbox series

[RFC/PATCH,11/18] ravb: Add rx_2k_buffers to struct ravb_hw_info

Message ID 20210923140813.13541-12-biju.das.jz@bp.renesas.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series Add Gigabit Ethernet driver support | expand

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Commit Message

Biju Das Sept. 23, 2021, 2:08 p.m. UTC
R-Car AVB-DMAC has Maximum 2K size on RZ buffer.
We need to Allow for changing the MTU within the
limit of the maximum size of a descriptor (2048 bytes).

Add a rx_2k_buffers hw feature bit to struct ravb_hw_info
to add this constraint only for R-Car.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
---
 drivers/net/ethernet/renesas/ravb.h      | 1 +
 drivers/net/ethernet/renesas/ravb_main.c | 8 ++++++--
 2 files changed, 7 insertions(+), 2 deletions(-)

Comments

Sergey Shtylyov Sept. 24, 2021, 7:35 p.m. UTC | #1
On 9/23/21 5:08 PM, Biju Das wrote:

> R-Car AVB-DMAC has Maximum 2K size on RZ buffer.
> We need to Allow for changing the MTU within the
> limit of the maximum size of a descriptor (2048 bytes).
> 
> Add a rx_2k_buffers hw feature bit to struct ravb_hw_info
> to add this constraint only for R-Car.
> 
> Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
> ---
>  drivers/net/ethernet/renesas/ravb.h      | 1 +
>  drivers/net/ethernet/renesas/ravb_main.c | 8 ++++++--
>  2 files changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ethernet/renesas/ravb.h b/drivers/net/ethernet/renesas/ravb.h
> index 7532cb51d7b8..ab4909244276 100644
> --- a/drivers/net/ethernet/renesas/ravb.h
> +++ b/drivers/net/ethernet/renesas/ravb.h
> @@ -1033,6 +1033,7 @@ struct ravb_hw_info {
>  	unsigned magic_pkt:1;		/* E-MAC supports magic packet detection */
>  	unsigned mii_rgmii_selection:1;	/* E-MAC supports mii/rgmii selection */
>  	unsigned half_duplex:1;		/* E-MAC supports half duplex mode */
> +	unsigned rx_2k_buffers:1;	/* AVB-DMAC has Max 2K buf size on RX */

   It seems more flexible to specify the buffer size, not just a bit like this...

[...]

MBR, Sergey
Biju Das Sept. 26, 2021, 3:48 p.m. UTC | #2
Hi Sergei,

> Subject: Re: [RFC/PATCH 11/18] ravb: Add rx_2k_buffers to struct
> ravb_hw_info
> 
> On 9/23/21 5:08 PM, Biju Das wrote:
> 
> > R-Car AVB-DMAC has Maximum 2K size on RZ buffer.
> > We need to Allow for changing the MTU within the limit of the maximum
> > size of a descriptor (2048 bytes).
> >
> > Add a rx_2k_buffers hw feature bit to struct ravb_hw_info to add this
> > constraint only for R-Car.
> >
> > Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
> > ---
> >  drivers/net/ethernet/renesas/ravb.h      | 1 +
> >  drivers/net/ethernet/renesas/ravb_main.c | 8 ++++++--
> >  2 files changed, 7 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/net/ethernet/renesas/ravb.h
> > b/drivers/net/ethernet/renesas/ravb.h
> > index 7532cb51d7b8..ab4909244276 100644
> > --- a/drivers/net/ethernet/renesas/ravb.h
> > +++ b/drivers/net/ethernet/renesas/ravb.h
> > @@ -1033,6 +1033,7 @@ struct ravb_hw_info {
> >  	unsigned magic_pkt:1;		/* E-MAC supports magic packet
> detection */
> >  	unsigned mii_rgmii_selection:1;	/* E-MAC supports mii/rgmii
> selection */
> >  	unsigned half_duplex:1;		/* E-MAC supports half duplex mode */
> > +	unsigned rx_2k_buffers:1;	/* AVB-DMAC has Max 2K buf size on RX
> */
> 
>    It seems more flexible to specify the buffer size, not just a bit like
> this...

Agreed, will use rx_max_buf_size variable on the next version.

Regards,
Biju
diff mbox series

Patch

diff --git a/drivers/net/ethernet/renesas/ravb.h b/drivers/net/ethernet/renesas/ravb.h
index 7532cb51d7b8..ab4909244276 100644
--- a/drivers/net/ethernet/renesas/ravb.h
+++ b/drivers/net/ethernet/renesas/ravb.h
@@ -1033,6 +1033,7 @@  struct ravb_hw_info {
 	unsigned magic_pkt:1;		/* E-MAC supports magic packet detection */
 	unsigned mii_rgmii_selection:1;	/* E-MAC supports mii/rgmii selection */
 	unsigned half_duplex:1;		/* E-MAC supports half duplex mode */
+	unsigned rx_2k_buffers:1;	/* AVB-DMAC has Max 2K buf size on RX */
 };
 
 struct ravb_private {
diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index 7f06adbd00e1..9c0d35f4b221 100644
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -2164,6 +2164,7 @@  static const struct ravb_hw_info ravb_gen3_hw_info = {
 	.ccc_gac = 1,
 	.multi_tsrq = 1,
 	.magic_pkt = 1,
+	.rx_2k_buffers = 1,
 };
 
 static const struct ravb_hw_info ravb_gen2_hw_info = {
@@ -2184,6 +2185,7 @@  static const struct ravb_hw_info ravb_gen2_hw_info = {
 	.aligned_tx = 1,
 	.multi_tsrq = 1,
 	.magic_pkt = 1,
+	.rx_2k_buffers = 1,
 };
 
 static const struct ravb_hw_info rgeth_hw_info = {
@@ -2417,8 +2419,10 @@  static int ravb_probe(struct platform_device *pdev)
 	}
 	clk_prepare_enable(priv->refclk);
 
-	ndev->max_mtu = 2048 - (ETH_HLEN + VLAN_HLEN + ETH_FCS_LEN);
-	ndev->min_mtu = ETH_MIN_MTU;
+	if (info->rx_2k_buffers) {
+		ndev->max_mtu = 2048 - (ETH_HLEN + VLAN_HLEN + ETH_FCS_LEN);
+		ndev->min_mtu = ETH_MIN_MTU;
+	}
 
 	/* FIXME: R-Car Gen2 has 4byte alignment restriction for tx buffer
 	 * Use two descriptor to handle such situation. First descriptor to