Re: [PATCH net-next] net: stmmac: dwmac4: Report DCB feature capability
From: Maxime Chevallier
Date: Thu Jun 04 2026 - 03:31:15 EST
Hi,
On 6/3/26 19:36, Ovidiu Panait wrote:
> Bit 16 of the MAC HW Feature1 register reports the DCB (Data Centre
> Bridging) feature. Read it so that dma_cap.dcben and the debugfs
> report it accurately. Right now it is always reported as being disabled.
>
> Signed-off-by: Ovidiu Panait <ovidiu.panait.rb@xxxxxxxxxxx>
This matches with what I have in the iMX8MP ref manual :)
Reviewed-by: Maxime Chevallier <maxime.chevallier@xxxxxxxxxxx>
Thank you,
Maxime
> ---
> drivers/net/ethernet/stmicro/stmmac/dwmac4.h | 1 +
> drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c | 1 +
> 2 files changed, 2 insertions(+)
>
> diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4.h b/drivers/net/ethernet/stmicro/stmmac/dwmac4.h
> index ffcd036d4c02..6382836828ba 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/dwmac4.h
> +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4.h
> @@ -198,6 +198,7 @@ enum power_event {
> #define GMAC_HW_FEAT_AVSEL BIT(20)
> #define GMAC_HW_TSOEN BIT(18)
> #define GMAC_HW_FEAT_SPHEN BIT(17)
> +#define GMAC_HW_FEAT_DCBEN BIT(16)
> #define GMAC_HW_ADDR64 GENMASK(15, 14)
> #define GMAC_HW_TXFIFOSIZE GENMASK(10, 6)
> #define GMAC_HW_RXFIFOSIZE GENMASK(4, 0)
> diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c b/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c
> index 28728271fbc9..829a23bdad01 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c
> @@ -391,6 +391,7 @@ static int dwmac4_get_hw_feature(void __iomem *ioaddr,
> dma_cap->av = (hw_cap & GMAC_HW_FEAT_AVSEL) >> 20;
> dma_cap->tsoen = (hw_cap & GMAC_HW_TSOEN) >> 18;
> dma_cap->sphen = (hw_cap & GMAC_HW_FEAT_SPHEN) >> 17;
> + dma_cap->dcben = (hw_cap & GMAC_HW_FEAT_DCBEN) >> 16;
>
> dma_cap->addr64 = (hw_cap & GMAC_HW_ADDR64) >> 14;
> switch (dma_cap->addr64) {