linux-kernel - Re: [PATCH v2 6/6] i2c: spacemit: introduce pio for k1

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: <20250927101648-GYA1338789@gentoo.org>
Date: Sat, 27 Sep 2025 18:16:48 +0800
From: Yixun Lan <dlan@...too.org>
To: Troy Mitchell <troy.mitchell@...ux.spacemit.com>
Cc: Andi Shyti <andi.shyti@...nel.org>, Alex Elder <elder@...cstar.com>,
	Troy Mitchell <troymitchell988@...il.com>,
	linux-i2c@...r.kernel.org, linux-kernel@...r.kernel.org,
	linux-riscv@...ts.infradead.org, spacemit@...ts.linux.dev
Subject: Re: [PATCH v2 6/6] i2c: spacemit: introduce pio for k1

Hi Troy,

On 12:04 Sat 27 Sep     , Troy Mitchell wrote:
> On Sat, Sep 27, 2025 at 09:45:47AM +0800, Yixun Lan wrote:
> > Hi Troy,
> > 
> > On 10:02 Thu 25 Sep     , Troy Mitchell wrote:
> > > This patch introduces I2C PIO functionality for the Spacemit K1 SoC,
> > > enabling the use of I2C with interrupts disabled.
> > I feel it's more proper to say
> > s/with interrupts disabled/in atomic context/
> Good point.
> 
> > 
> > I've noticed that K1 I2C controller support three different transmission mode:
> >  non-fifo, fifo mode, dma mode
> > 
> > while you are trying to implement pio support, I'd suggest to think one
> > further step in the long run - support more fifo/dma + normal/atomic features,
> I understand your concern, but I have reviewed the code structure,
> and adding FIFO support would not significantly affect the current PIO implementation.
we will see..

> 
> > 
> > Personally, I'd like to see fifo mode implemented before adding pio
> > support, as it will bring quite significant code changes, require heavy
> > code review effort. And yes, this will put more demanding work on your side
> > and may slow things a bit..
> That said, we don’t have any plans to support FIFO at this point,
> and PIO functionality is something we need urgently.
> So I will continue to push this patch (tomorrow).
please do not flush the mailing list and give people some time, I haven't seen 
enough reviews coming, please wait for ~one week before sending next version,
or make sure you've accumulated enough changes..

> Thanks for your understanding. For details on the code changes, please see above.
> 
> In addition, if anyone is interested in adding FIFO support, I’d be happy to help.
> 
do you want to push the work (support fifo mode) to community?

-- 
Yixun Lan (dlan)