lkml.org 
[lkml]   [2020]   [Oct]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH net-next 7/8] net: ethernet: ti: am65-cpsw: prepare xmit/rx path for multi-port devices in mac-only mode
From
From: Grygorii Strashko <grygorii.strashko@ti.com>
Date: Thu, 1 Oct 2020 13:52:57 +0300

> This patch adds multi-port support to TI AM65x CPSW driver xmit/rx path in
> preparation for adding support for multi-port devices, like Main CPSW0 on
> K3 J721E SoC or future CPSW3g on K3 AM64x SoC.
> Hence DMA channels are common/shared for all ext Ports and the RX/TX NAPI
> and DMA processing going to be assigned to first netdev this patch:
> - ensures all RX descriptors fields are initialized;
> - adds synchronization for TX DMA push/pop operation (locking) as
> Networking core is not enough any more;
> - updates TX bql processing for every packet in
> am65_cpsw_nuss_tx_compl_packets() as every completed TX skb can have
> different ndev assigned (come from different netdevs).
>
> Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>

This locking is unnecessary in single-port non-shared DMA situations
and therefore will impose unnecessary performance loss for basically
all existing supported setups.

Please do this another way.

In fact, I would encourage you to find a way to avoid the new atomic
operations even in multi-port configurations.

Thank you.

\
 
 \ /
  Last update: 2020-10-03 04:10    [W:0.131 / U:10.284 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site