Re: [PATCH net-next 2/2] net: stmmac: make stmmac-tx-timeout configurable in Kconfig

[Heiner Kallweit <hkallweit1@gmail.com>]

On 01.12.2021 02:47, Xiaoliang Yang wrote:
> stmmac_tx_timeout() function is called when a queue transmission
> timeout. When Strict Priority is used as scheduling algorithms, the
> lower priority queue may be blocked by a higher prority queue, which
> will lead to tx timeout. We don't want to enable the tx watchdog timeout
> in this case. Therefore, this patch make stmmac-tx-timeout configurable.
> 
Your patch just disables the timeout handler, the WARN_ONCE() would
still fire. And shouldn't this be a runtime setting rather than a
compile-time setting?

> This patch set the CONFIG_STMMAC_TX_TIMEOUT by default when STMMAC_ETH
> is selected. If anyone want to disable the tx watchdog timeout of
> stmmac, he can unset the CONFIG_STMMAC_TX_TIMEOUT in menuconfig.
> 
> Signed-off-by: Xiaoliang Yang <xiaoliang.yang_1@nxp.com>
> ---
>  drivers/net/ethernet/stmicro/stmmac/Kconfig       | 12 ++++++++++++
>  drivers/net/ethernet/stmicro/stmmac/stmmac_main.c |  4 ++++
>  2 files changed, 16 insertions(+)
> 
> diff --git a/drivers/net/ethernet/stmicro/stmmac/Kconfig b/drivers/net/ethernet/stmicro/stmmac/Kconfig
> index 929cfc22cd0c..856c7d056b61 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/Kconfig
> +++ b/drivers/net/ethernet/stmicro/stmmac/Kconfig
> @@ -271,4 +271,16 @@ config STMMAC_PCI
>  	  If you have a controller with this interface, say Y or M here.
>  
>  	  If unsure, say N.
> +
> +config STMMAC_TX_TIMEOUT
> +	bool "STMMAC TX timeout support"
> +	default STMMAC_ETH
> +	depends on STMMAC_ETH
> +	help
> +	  Support for TX timeout enable on stmmac.
> +
> +	  This selects the TX watchdog timeout support for stmmac driver. The
> +	  feature is enabled by default when STMMAC_ETH is selected. If you
> +	  want to disable the TX watchdog timeout feature, say N here.
> +
>  endif
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> index 89a6c35e2546..0a712b5d0715 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> @@ -5421,6 +5421,7 @@ static int stmmac_napi_poll_rxtx(struct napi_struct *napi, int budget)
>  	return min(rxtx_done, budget - 1);
>  }
>  
> +#ifdef CONFIG_STMMAC_TX_TIMEOUT
>  /**
>   *  stmmac_tx_timeout
>   *  @dev : Pointer to net device structure
> @@ -5436,6 +5437,7 @@ static void stmmac_tx_timeout(struct net_device *dev, unsigned int txqueue)
>  
>  	stmmac_global_err(priv);
>  }
> +#endif
>  
>  /**
>   *  stmmac_set_rx_mode - entry point for multicast addressing
> @@ -6632,7 +6634,9 @@ static const struct net_device_ops stmmac_netdev_ops = {
>  	.ndo_fix_features = stmmac_fix_features,
>  	.ndo_set_features = stmmac_set_features,
>  	.ndo_set_rx_mode = stmmac_set_rx_mode,
> +#ifdef CONFIG_STMMAC_TX_TIMEOUT
>  	.ndo_tx_timeout = stmmac_tx_timeout,
> +#endif
>  	.ndo_eth_ioctl = stmmac_ioctl,
>  	.ndo_setup_tc = stmmac_setup_tc,
>  	.ndo_select_queue = stmmac_select_queue,
>