Re: Aw: [PATCH net] net: ethernet: mtk_eth_soc: fix tx throughput regression with direct 1G links

[Felix Fietkau <nbd@nbd.name>]

On 25.03.23 10:28, Frank Wunderlich wrote:
>> Gesendet: Freitag, 24. März 2023 um 15:04 Uhr
>> Von: "Felix Fietkau" <nbd@nbd.name>
>> An: netdev@vger.kernel.org
>> Cc: "Frank Wunderlich" <frank-w@public-files.de>, "Daniel Golle" <daniel@makrotopia.org>
>> Betreff: [PATCH net] net: ethernet: mtk_eth_soc: fix tx throughput regression with direct 1G links
>>
>> Using the QDMA tx scheduler to throttle tx to line speed works fine for
>> switch ports, but apparently caused a regression on non-switch ports.
>> 
>> Based on a number of tests, it seems that this throttling can be safely
>> dropped without re-introducing the issues on switch ports that the
>> tx scheduling changes resolved.
>> 
>> Link: https://lore.kernel.org/netdev/trinity-92c3826f-c2c8-40af-8339-bc6d0d3ffea4-1678213958520@3c-app-gmx-bs16/
>> Fixes: f63959c7eec3 ("net: ethernet: mtk_eth_soc: implement multi-queue support for per-port queues")
>> Reported-by: Frank Wunderlich <frank-w@public-files.de>
>> Reported-by: Daniel Golle <daniel@makrotopia.org>
>> Tested-by: Daniel Golle <daniel@makrotopia.org>
>> Signed-off-by: Felix Fietkau <nbd@nbd.name>
>> ---
>>  drivers/net/ethernet/mediatek/mtk_eth_soc.c | 2 --
>>  1 file changed, 2 deletions(-)
>> 
>> diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
>> index a94aa08515af..282f9435d5ff 100644
>> --- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
>> +++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
>> @@ -763,8 +763,6 @@ static void mtk_mac_link_up(struct phylink_config *config,
>>  		break;
>>  	}
>>  
>> -	mtk_set_queue_speed(mac->hw, mac->id, speed);
>> -
>>  	/* Configure duplex */
>>  	if (duplex == DUPLEX_FULL)
>>  		mcr |= MAC_MCR_FORCE_DPX;
> 
> thx for the fix, as daniel already checked it on mt7986/bpi-r3 i tested bpi-r2/mt7623
> 
> but unfortunately it does not fix issue on bpi-r2 where the gmac0/mt7530 part is affected.
> 
> maybe it needs a special handling like you do for mt7621? maybe it is because the trgmii mode used on this path?
Could you please test if making it use the MT7621 codepath brings back 
performance? I don't have any MT7623 hardware for testing right now.

- Felix