[PATCH] net: stmmac: set multicast filter to zero if feature is unsupported

[Yanteng Si]

在 5/24/25 6:19 AM, Nikunj Kela 写道:
> Hash based multicast filtering is an optional feature. Currently,
> driver overrides the value of multicast_filter_bins based on the hash
> table size. If the feature is not supported, hash table size reads 0
> however the value of multicast_filter_bins remains set to default
> HASH_TABLE_SIZE which is incorrect. Let's override it to 0 if the
> feature is unsupported.
> 
> Signed-off-by: Nikunj Kela <nikunj.kela at sima.ai>
> ---
>   drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 3 +++
>   1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> index 085c09039af4..ccea9f811a05 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> @@ -7241,6 +7241,9 @@ static int stmmac_hw_init(struct stmmac_priv *priv)
>   					(BIT(priv->dma_cap.hash_tb_sz) << 5);
>   			priv->hw->mcast_bits_log2 =
>   					ilog2(priv->hw->multicast_filter_bins);
> +		} else {
> +			priv->hw->multicast_filter_bins = 0;
> +			priv->hw->mcast_bits_log2 = 0;
>   		}

I didn't read the code carefully, just did a simple search：

❯ grep -rn multicast_filter_bins drivers/net/
drivers/net/ethernet/stmicro/stmmac/common.h:611:	unsigned int 
multicast_filter_bins;
drivers/net/ethernet/stmicro/stmmac/dwmac-sophgo.c:26: 
plat_dat->multicast_filter_bins = 0;
***
drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c:512: 
plat->multicast_filter_bins = HASH_TABLE_SIZE;
***
drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c:536:				 
&plat->multicast_filter_bins);
drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c:541:	 
plat->multicast_filter_bins = dwmac1000_validate_mcast_bins(
drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c:542:			 
&pdev->dev, plat->multicast_filter_bins);
drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c:523: 
mac->multicast_filter_bins = priv->plat->multicast_filter_bins;
drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c:527:	if 
(mac->multicast_filter_bins)
drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c:528:	 
mac->mcast_bits_log2 = ilog2(mac->multicast_filter_bins);
drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c:516:		 
(netdev_mc_count(dev) > hw->multicast_filter_bins)) {
drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c:1527: 
mac->multicast_filter_bins = priv->plat->multicast_filter_bins;
drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c:1531:	if 
(mac->multicast_filter_bins)
drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c:1532:	 
mac->mcast_bits_log2 = ilog2(mac->multicast_filter_bins);
drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c:1568: 
mac->multicast_filter_bins = priv->plat->multicast_filter_bins;
drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c:1572:	if 
(mac->multicast_filter_bins)
drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c:1573:	 
mac->mcast_bits_log2 = ilog2(mac->multicast_filter_bins);
drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c:543:	if 
(netdev_mc_count(priv->dev) >= priv->hw->multicast_filter_bins)
drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c:633:	if 
(netdev_mc_count(priv->dev) >= priv->hw->multicast_filter_bins)
drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c:679:	if 
(netdev_mc_count(priv->dev) >= priv->hw->multicast_filter_bins)
drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c:31: 
plat->multicast_filter_bins = HASH_TABLE_SIZE;
drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c:84: 
plat->multicast_filter_bins = HASH_TABLE_SIZE;
drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c:98: 
plat->multicast_filter_bins = 256;
drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c:365: 
mac->multicast_filter_bins = priv->plat->multicast_filter_bins;
drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c:369:	if 
(mac->multicast_filter_bins)
drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c:370:	 
mac->mcast_bits_log2 = ilog2(mac->multicast_filter_bins);
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c:7240:		 
priv->hw->multicast_filter_bins =
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c:7243:				 
ilog2(priv->hw->multicast_filter_bins);
drivers/net/ethernet/stmicro/stmmac/dwmac-intel.c:570: 
plat->multicast_filter_bins = HASH_TABLE_SIZE;
drivers/net/ethernet/stmicro/stmmac/dwmac-intel.c:707: 
plat->multicast_filter_bins = HASH_TABLE_SIZE;
drivers/net/ethernet/stmicro/stmmac/dwmac-ipq806x.c:479: 
plat_dat->multicast_filter_bins = 0;
drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c:456:	int numhashregs = 
(hw->multicast_filter_bins >> 5);
drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c:485:		 
(netdev_mc_count(dev) > hw->multicast_filter_bins)) {
drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c:1057: 
mac->multicast_filter_bins = priv->plat->multicast_filter_bins;
drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c:1061:	if 
(mac->multicast_filter_bins)
drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c:1062:	 
mac->mcast_bits_log2 = ilog2(mac->multicast_filter_bins);
drivers/net/ethernet/stmicro/stmmac/dwmac-generic.c:43:	 
plat_dat->multicast_filter_bins = HASH_TABLE_SIZE;

and

drivers/net/ethernet/stmicro/stmmac/common.h:265:#define HASH_TABLE_SIZE 64


 From the search results, the default value of multicast_filter_bins
may be meaningful. And I think that even if some hardware does not
support this feature, it should still be overridden in its own directory.


Thanks,
Yanteng