linux-kernel - Re: [PATCH v10 01/11] usb: typec: Add notifier functions

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: <2025112656-dreamland-retreat-2a65@gregkh>
Date: Wed, 26 Nov 2025 12:44:17 +0100
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: Heikki Krogerus <heikki.krogerus@...ux.intel.com>
Cc: Chaoyi Chen <chaoyi.chen@...k-chips.com>,
	Chaoyi Chen <kernel@...kyi.com>,
	Dmitry Baryshkov <dmitry.baryshkov@....qualcomm.com>,
	Peter Chen <hzpeterchen@...il.com>,
	Luca Ceresoli <luca.ceresoli@...tlin.com>,
	Rob Herring <robh@...nel.org>,
	Krzysztof Kozlowski <krzk+dt@...nel.org>,
	Conor Dooley <conor+dt@...nel.org>, Vinod Koul <vkoul@...nel.org>,
	Kishon Vijay Abraham I <kishon@...nel.org>,
	Heiko Stuebner <heiko@...ech.de>, Sandy Huang <hjc@...k-chips.com>,
	Andy Yan <andy.yan@...k-chips.com>,
	Yubing Zhang <yubing.zhang@...k-chips.com>,
	Frank Wang <frank.wang@...k-chips.com>,
	Andrzej Hajda <andrzej.hajda@...el.com>,
	Neil Armstrong <neil.armstrong@...aro.org>,
	Robert Foss <rfoss@...nel.org>,
	Laurent Pinchart <Laurent.pinchart@...asonboard.com>,
	Jonas Karlman <jonas@...boo.se>,
	Jernej Skrabec <jernej.skrabec@...il.com>,
	Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
	Maxime Ripard <mripard@...nel.org>,
	Thomas Zimmermann <tzimmermann@...e.de>,
	David Airlie <airlied@...il.com>, Simona Vetter <simona@...ll.ch>,
	Amit Sunil Dhamne <amitsd@...gle.com>,
	Dragan Simic <dsimic@...jaro.org>, Johan Jonker <jbx6244@...il.com>,
	Diederik de Haas <didi.debian@...ow.org>,
	Peter Robinson <pbrobinson@...il.com>, linux-usb@...r.kernel.org,
	devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
	linux-phy@...ts.infradead.org, linux-arm-kernel@...ts.infradead.org,
	linux-rockchip@...ts.infradead.org, dri-devel@...ts.freedesktop.org
Subject: Re: [PATCH v10 01/11] usb: typec: Add notifier functions

On Wed, Nov 26, 2025 at 11:42:43AM +0200, Heikki Krogerus wrote:
> Wed, Nov 26, 2025 at 09:46:19AM +0800, Chaoyi Chen kirjoitti:
> > On 11/25/2025 7:49 PM, Greg Kroah-Hartman wrote:
> > >> +static umode_t typec_is_visible(struct kobject *kobj, struct attribute *attr, int n)
> > >> +{
> > >> +	if (is_typec_port(kobj_to_dev(kobj)->parent))
> > > 
> > > Why look at the parent?  Doesn't the device have a type that should show
> > > this?
> > > 
> > > Otherwise, looks good to me.
> > 
> > They have same deivce type "typec_altmode_dev_type".
> > The parent device has a different device type to distinguish between
> > port device and partner device.
> 
> I was already wondering would it make sense to provide separate device
> types for the port, and also plug, alternate modes, but I'm not sure
> if that's the right thing to do.
> 
> There is a plan to register an "altmode" also for the USB4 mode,
> which of course is not an alternate mode. So USB4 will definitely need a
> separate device type.
> 
> So if we supply separate device types for the port, plug and partner
> alternate modes, we need to supply separate device types for port, plug
> and partner USB4 mode as well.
> 
> We certainly can still do that, but I'm just not sure if it makes
> sense?
> 
> I'll prepare a new version for this and include a separate patch where
> instead of defining separate device types for the port and plug
> alternate modes I'll just supply helpers is_port_alternate_mode() and
> is_plug_alternate_mode().

That feels like it would be better in the long run as it would be
easier to "match" on the device type.

thanks,

greg k-h