On 04/02/2025 16:13, Chen-Yu Tsai wrote:
> From: Chen-Yu Tsai <wens@xxxxxxxx>
>
> The DWMAC 1000 DMA capabilities register does not provide actual
> FIFO sizes, nor does the driver really care. If they are not
> provided via some other means, the driver will work fine, only
> disallowing changing the MTU setting.
>
> The recent commit 8865d22656b4 ("net: stmmac: Specify hardware
> capability value when FIFO size isn't specified") changed this by
> requiring the FIFO sizes to be provided, breaking devices that were
> working just fine.
>
> Provide the FIFO sizes through the driver's platform data, to not
> only fix the breakage, but also enable MTU changes. The FIFO sizes
> are confirmed to be the same across RK3288, RK3328, RK3399 and PX30,
> based on their respective manuals. It is likely that Rockchip
> synthesized their DWMAC 1000 with the same parameters on all their
> chips that have it.
>
> Fixes: eaf4fac47807 ("net: stmmac: Do not accept invalid MTU values")
> Fixes: 8865d22656b4 ("net: stmmac: Specify hardware capability value when FIFO size isn't specified")
> Cc: <stable@xxxxxxxxxxxxxxx>
> Signed-off-by: Chen-Yu Tsai <wens@xxxxxxxx>
I think it's better at this stage to apply the revert first. However
I've run this on my board (Firefly RK3288) and it works, so when rebased
onto the (reverted) revert:
Tested-by: Steven Price <steven.price@xxxxxxx>
Thanks,
Steve
> ---
> The reason for stable inclusion is not to fix the device breakage
> (which only broke in v6.14-rc1), but to provide the values so that MTU
> changes can work in older kernels.
>
> Since a fix for stmmac in general has already been sent [1] and a revert
> was also proposed [2], I'll refrain from sending mine.
>
> [1] https://lore.kernel.org/all/20250203093419.25804-1-steven.price@xxxxxxx/
> [2] https://lore.kernel.org/all/Z6Clkh44QgdNJu_O@xxxxxxxxxxxxxxxxxxxxx/
>
> drivers/net/ethernet/stmicro/stmmac/dwmac-rk.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-rk.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-rk.c
> index a4dc89e23a68..71a4c4967467 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/dwmac-rk.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-rk.c
> @@ -1966,8 +1966,11 @@ static int rk_gmac_probe(struct platform_device *pdev)
> /* If the stmmac is not already selected as gmac4,
> * then make sure we fallback to gmac.
> */
> - if (!plat_dat->has_gmac4)
> + if (!plat_dat->has_gmac4) {
> plat_dat->has_gmac = true;
> + plat_dat->rx_fifo_size = 4096;
> + plat_dat->tx_fifo_size = 2048;
> + }
> plat_dat->fix_mac_speed = rk_fix_speed;
>
> plat_dat->bsp_priv = rk_gmac_setup(pdev, plat_dat, data);
