Re: [EXT] Re: [PATCH 1/1] dt-bindings: usb: ci-hdrc-usb2: Fix number of clocks

[Alexander Stein <alexander.stein@ew.tq-group.com>]

Hi Xu Yang,

thanks for your feedback.

Am Freitag, 7. Juli 2023, 09:06:09 CEST schrieb Xu Yang:
> Hi Alexander,
> 
> > -----Original Message-----
> > 
> > Hi,
> > 
> > Am Donnerstag, 6. Juli 2023, 21:18:25 CEST schrieb Rob Herring:
> > > On Thu, Jul 06, 2023 at 11:39:28AM +0200, Alexander Stein wrote:
> > > > Some (older) IP cores require 3 clocks, named 'ipg', 'ahb' and 'per'
> > > > while
> > > > more recent IP cores just require one. Fix the number and explicitly
> > > > state the clock-names.
> > > > 
> > > > Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
> > > > ---
> > > > 
> > > > >From I can tell, is that imx25, imx27, imx35 have specified 3 clocks
> > > > >in
> > > > 
> > > > their DT.
> > > > IMHO minItems for 'clock-names' can be removed as I presume that this
> > > > property is not set when only one clock is used.
> > > 
> > > Rather than presume, did you test that? Well, I did[1] and can confirm.
> > 
> > Okay, probably my wording was bad. There are a lot of users (e.g. imx8mm,
> > imx8mn) which only have one clock but still provide some clock-names
> > property. It works just because it is not called 'ipg', but some SoC
> > specific clock name.
> > So this patch should cause some warnings, but these users were incorrect
> > in
> > the first place. Following up this patch, they need to be fixed.
> 
> It means that all the usb nodes need to contain 'ipg', 'ahb', 'per' clock
> names with your patch.

That's not true. They only need these 3 clocks iff they specify clock-names. 
If there is only one clock, there is no need to specify clock-names.
TBH: If there is just one clock, which is not called 'ipg', the driver doesn't 
care about the name at all.

> It's unexpected due to only imx25, imx27, imx35
> need this. I think you need to narrow this property to specific SoCs.

That's a good idea, but I would consider adding property conditionals as a 
follow up patch.

Best regards,
Alexander

> Thanks,
> Xu Yang
> 
> > Best regards,
> > Alexander
> > 
> > > Reviewed-by: Rob Herring <robh@kernel.org>


-- 
TQ-Systems GmbH | Mühlstraße 2, Gut Delling | 82229 Seefeld, Germany
Amtsgericht München, HRB 105018
Geschäftsführer: Detlef Schneider, Rüdiger Stahl, Stefan Schneider
http://www.tq-group.com/