linux-kernel - Re: [PATCH v5 1/4] i2c: designware: Add quirk for Intel Xe

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Message-ID: <aGKcTCSL4QMkx86I@kuha.fi.intel.com>
Date: Mon, 30 Jun 2025 17:16:44 +0300
From: Heikki Krogerus <heikki.krogerus@...ux.intel.com>
To: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@...el.com>,
	Lucas De Marchi <lucas.demarchi@...el.com>,
	Thomas Hellström <thomas.hellstrom@...ux.intel.com>,
	Jarkko Nikula <jarkko.nikula@...ux.intel.com>,
	David Airlie <airlied@...il.com>, Simona Vetter <simona@...ll.ch>,
	Mika Westerberg <mika.westerberg@...ux.intel.com>,
	Jan Dabros <jsd@...ihalf.com>, Andi Shyti <andi.shyti@...nel.org>,
	Raag Jadav <raag.jadav@...el.com>,
	"Tauro, Riana" <riana.tauro@...el.com>,
	"Adatrao, Srinivasa" <srinivasa.adatrao@...el.com>,
	"Michael J. Ruhl" <michael.j.ruhl@...el.com>,
	intel-xe@...ts.freedesktop.org, linux-i2c@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH v5 1/4] i2c: designware: Add quirk for Intel Xe

On Mon, Jun 30, 2025 at 04:16:56PM +0300, Andy Shevchenko wrote:
> On Mon, Jun 30, 2025 at 02:59:21PM +0300, Heikki Krogerus wrote:
> > On Mon, Jun 30, 2025 at 01:02:56PM +0300, Andy Shevchenko wrote:
> > > On Mon, Jun 30, 2025 at 11:10:00AM +0300, Heikki Krogerus wrote:
> > > > On Mon, Jun 30, 2025 at 10:30:19AM +0300, Andy Shevchenko wrote:
> > > > > On Fri, Jun 27, 2025 at 05:32:01PM -0400, Rodrigo Vivi wrote:
> > > > > > On Fri, Jun 27, 2025 at 05:13:36PM +0300, Andy Shevchenko wrote:
> > > > > > > On Fri, Jun 27, 2025 at 04:53:11PM +0300, Heikki Krogerus wrote:
> 
> ...
> 
> > > > > > > >  static int dw_i2c_plat_probe(struct platform_device *pdev)
> > > > > > > >  {
> > > > > > > > +	u32 flags = (uintptr_t)device_get_match_data(&pdev->dev);
> > > > > > > 
> > > > > > > > -	dev->flags = (uintptr_t)device_get_match_data(device);
> > > > > > > >  	if (device_property_present(device, "wx,i2c-snps-model"))
> > > > > > > > -		dev->flags = MODEL_WANGXUN_SP | ACCESS_POLLING;
> > > > > > > > +		flags = MODEL_WANGXUN_SP | ACCESS_POLLING;
> > > > > > > >  
> > > > > > > >  	dev->dev = device;
> > > > > > > >  	dev->irq = irq;
> > > > > > > > +	dev->flags = flags;
> > > > > > > 
> > > > > > > Maybe I'm missing something, but why do we need these (above) changes?
> > > > > > 
> > > > > > in between, it is introduced a new one:
> > > > > > flags |= ACCESS_POLLING;
> > > > > > 
> > > > > > So, the initialization moved up, before the ACCESS_POLLING, and
> > > > > > it let the assignment to the last, along with the group.
> > > > > 
> > > > > I still don't get. The cited code is complete equivalent.
> > > > 
> > > > This was requested by Jarkko.
> > > 
> > > Okay, but why? Sounds to me like unneeded churn. Can't we do this later when
> > > required?
> > 
> > You need to ask why from Jarkko - I did not really question him on
> > this one. Unfortunately his on vacation at the moment.
> 
> Yeah :-(
> 
> > I can drop this, but then I'll have to drop also Jarkko's ACK.
> 
> I can give mine if it helps. The code as far as I can see is 100% equivalent.
> 
> > I think we already agreed that this function, and probable the entire
> > file, need to be refactored a bit, so would you mind much if we just
> > went ahead with this as it is?
> > 
> > I'm asking that also because I don't have means or time to test this
> > anymore before I start my vacation.
> 
> I see, then we may ask Andi and Wolfram on this. I slightly prefer to have
> no additional churn added without a good reason.

OK. I'll fix this.

thanks,

-- 
heikki