linux-kernel - Re: (subset) [PATCH v3 0/3] spi: xilinx: switch to device properties and make IRQs optional

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: <aff8daa3-61e4-4808-8be9-45349c2f5de9@sirena.org.uk>
Date: Wed, 21 Jan 2026 12:35:55 +0000
From: Mark Brown <broonie@...nel.org>
To: Michal Simek <michal.simek@....com>
Cc: Rob Herring <robh@...nel.org>, Krzysztof Kozlowski <krzk+dt@...nel.org>,
	Conor Dooley <conor+dt@...nel.org>,
	Abdurrahman Hussain <abdurrahman@...thop.ai>,
	linux-spi@...r.kernel.org, devicetree@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: Re: (subset) [PATCH v3 0/3] spi: xilinx: switch to device properties
 and make IRQs optional

On Wed, Jan 21, 2026 at 01:26:04PM +0100, Michal Simek wrote:
> On 1/21/26 12:39, Mark Brown wrote:

> > My understanding was that the hardware doesn't require physically wiring
> > up the interrupt signal and can work in a polling only mode.  That's not
> > unknown for SPI controllers.  If the interrupt is actually a strong
> > requirement for the hardware (and especially if it is actually wired up
> > on this system) then we should drop these patches.

> Keep in mind one thing. This is soft IP in fpga. If you connect in design
> IRQ you will have it. If you don't connect it, you don't have it.
> From HW perspective both of them are valid options.

Yes, that's what I thought was happening - this means that it's valid to
not describe an interrupt for the device.  It's not like a primary clock
where the device simply won't function without it being wired up.

> Then the question is if DT binding in Linux are targeting HW capability and
> configurations or describing Linux driver. I was said multiple times that it
> should describe HW not actually what Linux driver implements.

Right, so if the hardware has an optional interrupt then the binding
should too.

Download attachment "signature.asc" of type "application/pgp-signature" (489 bytes)