From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 83C4D4A1A; Wed, 10 Sep 2025 13:31:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757511100; cv=none; b=Gj5pEOjZvf8UccGW0nYe4Ps1WUy12YoWqJzWsg83L8FEQhi6vkRriLq3EFQ8DWiYMPQPcNNx3nktZIjhG88Nt2cHxMv+1SaFo93r6RnqgL0RryzvBg3yYGDVoOhMu+3mQLsYEtz5cE7dZdkyT6KSFioJ+a05THflN/2Q3ZmHJQY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757511100; c=relaxed/simple; bh=UDpje6m1xlgONj6ZK3LPa5ZB65IKuApE8hhhpSoZSZU=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=FBcsCZqYZAfMMEwhf+KIMmr1y9GCl03lFC8MOv44EJCVtLm4Flh6vz8MuKAux5CvrV7618zEOex61/IMxtiXuk/AlkRI6LuUhDPIEMheWWvhwPFwAcKKhN/Tii03OA97nhWuhIBYz+jMt/bOjny/zyoipwmf2O9bibnsgEUe0+c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=MFExHsTn; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="MFExHsTn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4158BC4CEF0; Wed, 10 Sep 2025 13:31:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1757511100; bh=UDpje6m1xlgONj6ZK3LPa5ZB65IKuApE8hhhpSoZSZU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=MFExHsTnPFKyUcqjBFXkokDS2qNnzJ4U3lyqbyLL3XjeT8sOye5qBo8Wg2JSbCf5z 72vl34xODtA2omsbutw1nIlI99rKEB4Am2Tz1kJ6lhp3oZgMt3c2JMc1qz5dm+GtkL DB/wxtJNLOYLRRwdu7HNrx9qQJr9IERJrVHXkvTQ= Date: Wed, 10 Sep 2025 15:31:37 +0200 From: Greg Kroah-Hartman To: Andrei Kuchynski Cc: Heikki Krogerus , Abhishek Pandit-Subedi , Benson Leung , Jameson Thies , Tzung-Bi Shih , linux-usb@vger.kernel.org, chrome-platform@lists.linux.dev, Guenter Roeck , Dmitry Baryshkov , "Christian A. Ehrhardt" , Venkat Jayaraman , linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 4/5] usb: typec: Implement alternate mode priority handling Message-ID: <2025091029-snarl-decimal-aea2@gregkh> References: <20250905142206.4105351-1-akuchynski@chromium.org> <20250905142206.4105351-5-akuchynski@chromium.org> Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250905142206.4105351-5-akuchynski@chromium.org> On Fri, Sep 05, 2025 at 02:22:05PM +0000, Andrei Kuchynski wrote: > This patch introduces APIs to manage the priority of USB Type-C alternate > modes. These APIs allow for setting and retrieving a priority number for > each mode. If a new priority value conflicts with an existing mode's > priority, the priorities of the conflicting mode and all subsequent modes > are automatically incremented to ensure uniqueness. > > Signed-off-by: Andrei Kuchynski > --- > drivers/usb/typec/Makefile | 2 +- > drivers/usb/typec/mode_selection.c | 38 ++++++++++++++++++++++++++++++ > drivers/usb/typec/mode_selection.h | 6 +++++ > include/linux/usb/typec_altmode.h | 1 + > 4 files changed, 46 insertions(+), 1 deletion(-) > create mode 100644 drivers/usb/typec/mode_selection.c > create mode 100644 drivers/usb/typec/mode_selection.h > > diff --git a/drivers/usb/typec/Makefile b/drivers/usb/typec/Makefile > index 7a368fea61bc..8a6a1c663eb6 100644 > --- a/drivers/usb/typec/Makefile > +++ b/drivers/usb/typec/Makefile > @@ -1,6 +1,6 @@ > # SPDX-License-Identifier: GPL-2.0 > obj-$(CONFIG_TYPEC) += typec.o > -typec-y := class.o mux.o bus.o pd.o retimer.o > +typec-y := class.o mux.o bus.o pd.o retimer.o mode_selection.o > typec-$(CONFIG_ACPI) += port-mapper.o > obj-$(CONFIG_TYPEC) += altmodes/ > obj-$(CONFIG_TYPEC_TCPM) += tcpm/ > diff --git a/drivers/usb/typec/mode_selection.c b/drivers/usb/typec/mode_selection.c > new file mode 100644 > index 000000000000..2179bf25f5d4 > --- /dev/null > +++ b/drivers/usb/typec/mode_selection.c > @@ -0,0 +1,38 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * Copyright 2025 Google LLC. > + */ > + > +#include "mode_selection.h" > +#include "class.h" > +#include "bus.h" > + > +static int increment_duplicated_priority(struct device *dev, void *data) > +{ > + struct typec_altmode **alt_target = (struct typec_altmode **)data; > + > + if (is_typec_altmode(dev)) { > + struct typec_altmode *alt = to_typec_altmode(dev); > + > + if (alt != *alt_target && alt->priority == (*alt_target)->priority) { > + alt->priority++; > + *alt_target = alt; > + return 1; > + } > + } > + > + return 0; > +} > + > +void typec_mode_set_priority(struct typec_altmode *alt, > + const unsigned int priority) > +{ > + struct typec_port *port = to_typec_port(alt->dev.parent); > + int res = 1; > + > + alt->priority = priority; > + > + while (res) > + res = device_for_each_child(&port->dev, &alt, > + increment_duplicated_priority); > +} > diff --git a/drivers/usb/typec/mode_selection.h b/drivers/usb/typec/mode_selection.h > new file mode 100644 > index 000000000000..cbf5a37e6404 > --- /dev/null > +++ b/drivers/usb/typec/mode_selection.h > @@ -0,0 +1,6 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > + > +#include > + > +void typec_mode_set_priority(struct typec_altmode *alt, > + const unsigned int priority); > diff --git a/include/linux/usb/typec_altmode.h b/include/linux/usb/typec_altmode.h > index b3c0866ea70f..571c6e00b54f 100644 > --- a/include/linux/usb/typec_altmode.h > +++ b/include/linux/usb/typec_altmode.h > @@ -28,6 +28,7 @@ struct typec_altmode { > int mode; > u32 vdo; > unsigned int active:1; > + unsigned int priority; What is the range of this? And this value is only incremented, never decremented? thanks, greg k-h