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From: marc.zyngier@arm•com (Marc Zyngier)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 1/4] of: Add of_parse_phandle_with_opt_args() helper function
Date: Wed, 30 Sep 2015 10:08:59 +0100	[thread overview]
Message-ID: <560BA6AB.3060500@arm.com> (raw)
In-Reply-To: <CAL_JsqLWPfi9ynLbkzHkpcSHHg3ciwCcAN1uGcjXhnBAXZ74zw@mail.gmail.com>

On 29/09/15 18:28, Rob Herring wrote:
> On Tue, Sep 22, 2015 at 12:52 PM, Marc Zyngier <marc.zyngier@arm•com> wrote:
>> of_parse_phandle_with_args() is slightly inflexible as it doesn't
>> allow the (unusual) case where the #*-cells property is not defined.
>> In order to support this, introduce of_parse_phandle_with_opt_args()
>> which assumes that #*-cells is zero when it is not defined,
> 
> zero or cell_count - 1?

Zero is how the lack of #msi-cells property is interpreted. (cell_count
- 1) is how this is implemented.

> I would be okay with always assuming zero rather than being an error
> if that simplifies things. It is not really the kernel's job to be a
> dtb validator.

I'd be fine with that too. I'd just like it to be a defined behaviour,
not an unexpected side effect.

> Also, I assume this was done for some compatibility? In general, we
> should be explicit, so "#msi-cells = <0>" should be recommended and we
> should update dts files if they are not.

I agree that over time, we should update the existing DTS. But I hear
Mark chanting "Stable DT" behind me, so I'm inclined to provide an
transition path... ;-)

I'll respin the series later today.

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...

  reply	other threads:[~2015-09-30  9:08 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-09-22 17:52 [PATCH 0/4] of: Handle multi-parent version of msi-parent Marc Zyngier
2015-09-22 17:52 ` [PATCH 1/4] of: Add of_parse_phandle_with_opt_args() helper function Marc Zyngier
2015-09-29 17:28   ` Rob Herring
2015-09-30  9:08     ` Marc Zyngier [this message]
2015-09-30 13:57     ` Mark Rutland
2015-09-30 15:39   ` Robin Murphy
2015-09-30 17:18     ` Marc Zyngier
2015-09-22 17:52 ` [PATCH 2/4] of: irq: Add support for the new definition of "msi-parent" Marc Zyngier
2015-09-23 14:39   ` Sergei Shtylyov
2015-09-27 10:29     ` Thomas Gleixner
2015-09-27 13:02       ` Sergei Shtylyov
2015-09-22 17:52 ` [PATCH 3/4] PCI/MSI: " Marc Zyngier
2015-09-22 17:52 ` [PATCH 4/4] irqchip/gic-v3-its: Parse new version of msi-parent property Marc Zyngier

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