netdev - Re: [PATCH net-next v13 06/15] net: stmmac: dwmac-loongson: Detach GMAC-specific platform data init

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

Message-ID: <qj4ogerklgciopzhqrge27dngmoi7ijui274zlbuz6qozubi7n@itih73kfumhn>
Date: Fri, 5 Jul 2024 13:59:42 +0300
From: Serge Semin <fancer.lancer@...il.com>
To: Yanteng Si <siyanteng@...ngson.cn>
Cc: andrew@...n.ch, hkallweit1@...il.com, peppe.cavallaro@...com, 
	alexandre.torgue@...s.st.com, joabreu@...opsys.com, Jose.Abreu@...opsys.com, 
	chenhuacai@...nel.org, linux@...linux.org.uk, guyinggang@...ngson.cn, 
	netdev@...r.kernel.org, chris.chenfeiyang@...il.com, si.yanteng@...ux.dev
Subject: Re: [PATCH net-next v13 06/15] net: stmmac: dwmac-loongson: Detach
 GMAC-specific platform data init

On Fri, Jul 05, 2024 at 06:45:50PM +0800, Yanteng Si wrote:
> 
> 在 2024/7/5 18:16, Serge Semin 写道:
> > > > Seeing the discussion has started anyway, could you please find out
> > > > whether the multi-channel controller will still work if the MSI IRQs
> > > > allocation failed? Will the multi-channel-ness still work in that
> > > > case?
> > > Based on my test results:
> > > 
> > > In this case, multi-channel controller don't work. If the MSI IRQs
> > > allocation
> > > 
> > > failed, NIC will work in single channel.
> > What does "NIC will work in single channel" mean? Do the driver
> > (network traffic flow with a normal performance) still work even with
> > the plat->tx_queues_to_use and plat->rx_queues_to_use fields set to
> > eight? If it's then the multi-channel-ness still seems to be working
> > but the IRQs are delivered via the common MAC IRQ. If you get to
> > experience the data loss, or poor performance, or no traffic flowing
> > at all, then indeed the non-zero channels IRQs aren't delivered.
> > 
> > So the main question how did you find out that the controller work in
> > single channel?
> 
> sorry, I meant that if the MSI allocation failed, it will fallback to INTx,
> in which case
> 
> only the single channel works.  if the MSI allocation failed, the
> multi-channel-ness
> 
> don't work.

Could you please clarify what are the symptoms by which you figured
out that the "multi-channel-ness" didn't work?

Suppose you have an LS2K2000 SoC-based device, the
plat->tx_queues_to_use and plat->rx_queues_to_use to eight and the
loongson_dwmac_msi_config() function call is omitted. What is
happening with the activated network interface and with the traffic
flow then?

-Serge(y)