linux-kernel - Re: [PATCH v2] dt-bindings: usb: usb-device: relax compatible pattern to a contains

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] [day] [month] [year] [list]

Message-ID: <174542188274.551504.11808715673086067536.robh@kernel.org>
Date: Wed, 23 Apr 2025 10:24:43 -0500
From: "Rob Herring (Arm)" <robh@...nel.org>
To: Quentin Schulz <foss+kernel@...il.net>
Cc: devicetree@...r.kernel.org, Conor Dooley <conor+dt@...nel.org>,
	Łukasz Czechowski <lukasz.czechowski@...umatec.com>,
	linux-kernel@...r.kernel.org, linux-usb@...r.kernel.org,
	Krzysztof Kozlowski <krzk+dt@...nel.org>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Quentin Schulz <quentin.schulz@...rry.de>
Subject: Re: [PATCH v2] dt-bindings: usb: usb-device: relax compatible
 pattern to a contains


On Fri, 18 Apr 2025 16:08:20 +0200, Quentin Schulz wrote:
> From: Quentin Schulz <quentin.schulz@...rry.de>
> 
> The dt-core typically allows multiple compatibles[1] but usb-device
> currently forces a single compatible.
> 
> This is an issue when multiple devices with slightly different productID
> all behave the same. This would require the driver to keep updating its
> compatible matching table to include this new productID instead of doing
> what is usually done: have two compatibles, the leftmost which matches
> exactly the HW device definition, and the rightmost one as a fallback
> which is assumed to be 100% compatible with the device at hand. If this
> assumption turns out to be wrong, it is easy to work around this without
> having to modify the device tree by handling the leftmost compatible in the driver.
> 
> [1] https://github.com/devicetree-org/dt-schema/blob/main/dtschema/schemas/dt-core.yaml#L21-L25
> 
> Signed-off-by: Quentin Schulz <quentin.schulz@...rry.de>
> ---
> This came up while working on fixing USB on an RK3399 Puma which has an
> onboard USB hub whose productID isn't in any driver compatible list
> but which can be supported by a driver with a slightly different
> productID matching another variant of the same IC, from the same
> datasheet.
> 
> See https://lore.kernel.org/linux-rockchip/20250326-onboard_usb_dev-v1-0-a4b0a5d1b32c@thaumatec.com/
> ---
> Changes in v2:
> - use contains: instead of pattern: to relax the check, similarly to
>   what's done for PCI (suggested by Rob),
> - Link to v1: https://lore.kernel.org/r/20250415-dt-binding-usb-device-compatibles-v1-1-90f3cff32aa0@cherry.de
> ---
>  Documentation/devicetree/bindings/usb/usb-device.yaml | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 

Reviewed-by: Rob Herring (Arm) <robh@...nel.org>