Re: [PATCH 10/11] net: macb: Add support for RP1's MACB variant

Florian Fainelli
2024-08-21T17:02:32Z

On 8/20/24 07:36, Andrea della Porta wrote:
> RaspberryPi RP1 contains Cadence's MACB core. Implement the
> changes to be able to operate the customization in the RP1.
>
> Signed-off-by: Andrea della Porta <andrea.porta@suse.com>

You are doing a lot of things, all at once, and you should consider
extracting your change into a smaller subset with bug fixes first:

- one commit which writes to the RBQPH the upper 32-bits of the RX ring
DMA address, that looks like a bug fix

- one commit which retriggers a buffer read, even though that appears to
be RP1 specific maybe, if not, then this is also a bug fix

- one commit that adds support for macb_shutdown() to kill DMA operations

- one commit which adds support for a configurable PHY reset line +
delay specified in milli seconds

- one commit which adds support for controling the interrupt coalescing
settings

And then you can add all of the RP1 specific bits like the AXI bridge
configuration.

[snip]

> @@ -1228,6 +1246,7 @@ struct macb_queue {
> dma_addr_t tx_ring_dma;
> struct work_struct tx_error_task;
> bool txubr_pending;
> + bool tx_pending;
> struct napi_struct napi_tx;
>
> dma_addr_t rx_ring_dma;
> @@ -1293,9 +1312,15 @@ struct macb {
>
> u32 caps;
> unsigned int dma_burst_length;
> + u8 aw2w_max_pipe;
> + u8 ar2r_max_pipe;
> + bool use_aw2b_fill;
>
> phy_interface_t phy_interface;
>
> + struct gpio_desc *phy_reset_gpio;
> + int phy_reset_ms;

The delay cannot be negative, so this needs to be unsigned int.

> +
> /* AT91RM9200 transmit queue (1 on wire + 1 queued) */
> struct macb_tx_skb rm9200_txq[2];
> unsigned int max_tx_length;
> diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
> index 11665be3a22c..5eb5be6c96fc 100644
> --- a/drivers/net/ethernet/cadence/macb_main.c
> +++ b/drivers/net/ethernet/cadence/macb_main.c
> @@ -41,6 +41,9 @@
> #include <linux/inetdevice.h>
> #include "macb.h"
>
> +static unsigned int txdelay = 35;
> +module_param(txdelay, uint, 0644);
> +
> /* This structure is only used for MACB on SiFive FU540 devices */
> struct sifive_fu540_macb_mgmt {
> void __iomem *reg;
> @@ -334,7 +337,7 @@ static int macb_mdio_wait_for_idle(struct macb *bp)
> u32 val;
>
> return readx_poll_timeout(MACB_READ_NSR, bp, val, val & MACB_BIT(IDLE),
> - 1, MACB_MDIO_TIMEOUT);
> + 100, MACB_MDIO_TIMEOUT);

Why do we need to increase how frequently we poll?
--
Florian