netdev - Re: [PATCH RFC net-next] net: stmmac: enable RPS and RBU interrupts

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <194679cb-f8e0-4195-b85b-8726b9f5b4f6@bootlin.com>
Date: Sat, 17 Jan 2026 14:52:39 +0100
From: Maxime Chevallier <maxime.chevallier@...tlin.com>
To: "Russell King (Oracle)" <rmk+kernel@...linux.org.uk>,
 Andrew Lunn <andrew@...n.ch>, Heiner Kallweit <hkallweit1@...il.com>
Cc: Alexandre Torgue <alexandre.torgue@...s.st.com>,
 Andrew Lunn <andrew+netdev@...n.ch>, "David S. Miller"
 <davem@...emloft.net>, Eric Dumazet <edumazet@...gle.com>,
 Jakub Kicinski <kuba@...nel.org>, linux-arm-kernel@...ts.infradead.org,
 linux-stm32@...md-mailman.stormreply.com,
 Maxime Coquelin <mcoquelin.stm32@...il.com>, netdev@...r.kernel.org,
 Paolo Abeni <pabeni@...hat.com>
Subject: Re: [PATCH RFC net-next] net: stmmac: enable RPS and RBU interrupts

Hi Russell,

On 17/01/2026 00:25, Russell King (Oracle) wrote:
> Enable receive process stopped and receive buffer unavailable
> interrupts, so that the statistic counters can be updated.
> 
> Signed-off-by: Russell King (Oracle) <rmk+kernel@...linux.org.uk>
> ---
> 
> Maxime,
> 
> You may find this patch useful, as it makes the "rx_buf_unav_irq"
> and "rx_process_stopped_irq" ethtool statistic counters functional.
> This means that the lack of receive descriptors can still be detected
> even if the receive side doesn't actually stall.

Nice ! I'll give a test and take a deeper look after the weekend :)

Thanks,

Maxime

> 
> I'm not sure why we publish these statistic counters if we don't
> enable the interrupts to allow them to ever be non-zero.
> 
>  drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.h | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.h b/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.h
> index 9d9077a4ac9f..d7f86b398abe 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.h
> +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.h
> @@ -99,6 +99,8 @@ static inline u32 dma_chanx_base_addr(const struct dwmac4_addrs *addrs,
>  #define DMA_CHAN_INTR_ENA_NIE_4_10	BIT(15)
>  #define DMA_CHAN_INTR_ENA_AIE_4_10	BIT(14)
>  #define DMA_CHAN_INTR_ENA_FBE		BIT(12)
> +#define DMA_CHAN_INTR_ENA_RPS		BIT(8)
> +#define DMA_CHAN_INTR_ENA_RBU		BIT(7)
>  #define DMA_CHAN_INTR_ENA_RIE		BIT(6)
>  #define DMA_CHAN_INTR_ENA_TIE		BIT(0)
>  
> @@ -107,6 +109,8 @@ static inline u32 dma_chanx_base_addr(const struct dwmac4_addrs *addrs,
>  					 DMA_CHAN_INTR_ENA_TIE)
>  
>  #define DMA_CHAN_INTR_ABNORMAL		(DMA_CHAN_INTR_ENA_AIE | \
> +					 DMA_CHAN_INTR_ENA_RPS | \
> +					 DMA_CHAN_INTR_ENA_RBU | \
>  					 DMA_CHAN_INTR_ENA_FBE)
>  /* DMA default interrupt mask for 4.00 */
>  #define DMA_CHAN_INTR_DEFAULT_MASK	(DMA_CHAN_INTR_NORMAL | \
> @@ -119,6 +123,8 @@ static inline u32 dma_chanx_base_addr(const struct dwmac4_addrs *addrs,
>  					 DMA_CHAN_INTR_ENA_TIE)
>  
>  #define DMA_CHAN_INTR_ABNORMAL_4_10	(DMA_CHAN_INTR_ENA_AIE_4_10 | \
> +					 DMA_CHAN_INTR_ENA_RPS | \
> +					 DMA_CHAN_INTR_ENA_RBU | \
>  					 DMA_CHAN_INTR_ENA_FBE)
>  /* DMA default interrupt mask for 4.10a */
>  #define DMA_CHAN_INTR_DEFAULT_MASK_4_10	(DMA_CHAN_INTR_NORMAL_4_10 | \