From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8894ACDB465 for ; Thu, 19 Oct 2023 08:19:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235174AbjJSITw (ORCPT ); Thu, 19 Oct 2023 04:19:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44328 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232788AbjJSITu (ORCPT ); Thu, 19 Oct 2023 04:19:50 -0400 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.7]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 79F3310F; Thu, 19 Oct 2023 01:19:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1697703588; x=1729239588; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=ck3Nj7TeuDIaUGkikDZDIlu7/KYPSN+1S/hD16NfZXM=; b=Wbq10O7XS+GnVKs+FbTT4Y6inD6wbNumyFFBKLjsw459nRfBaPIXHYog XsNuciBNI4h13cGLq6M1TNbTf8Hx7qJ2++wE96MumcvoNnFh+pe1UKdAK CJHc25brC4rByzbiQvU9J1xSnmnS+yLQBJdIVa2oHlbO8FKvSx5b6TPG3 3q5m+ox+U1kochiTGFezJtOxdzi9Ho5S/7JkiWnn49bLk4LChzst+w5lP R0k23T4aqh8F3sBQ8Pk+we3r4oDu0LOGKheUEu1ouaOcgfI7LNI58i87J 0isEN/rJtGlI9KEoFfTZ+cydH4gk37PNU/4oqPb1oIeHQmQJw88lGEaUb A==; X-IronPort-AV: E=McAfee;i="6600,9927,10867"; a="7754659" X-IronPort-AV: E=Sophos;i="6.03,236,1694761200"; d="scan'208";a="7754659" Received: from orsmga006.jf.intel.com ([10.7.209.51]) by fmvoesa101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Oct 2023 01:19:48 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10867"; a="733480694" X-IronPort-AV: E=Sophos;i="6.03,236,1694761200"; d="scan'208";a="733480694" Received: from kuha.fi.intel.com ([10.237.72.185]) by orsmga006.jf.intel.com with SMTP; 19 Oct 2023 01:19:45 -0700 Received: by kuha.fi.intel.com (sSMTP sendmail emulation); Thu, 19 Oct 2023 11:19:44 +0300 Date: Thu, 19 Oct 2023 11:19:44 +0300 From: Heikki Krogerus To: RD Babiera Cc: gregkh@linuxfoundation.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, badhri@google.com, stable@vger.kernel.org Subject: Re: [PATCH v2] usb: typec: altmodes/displayport: verify compatible source/sink role combination Message-ID: References: <20231018203408.202845-2-rdbabiera@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20231018203408.202845-2-rdbabiera@google.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Oct 18, 2023 at 08:34:09PM +0000, RD Babiera wrote: > DisplayPort Alt Mode CTS test 10.3.8 states that both sides of the > connection shall be compatible with one another such that the connection > is not Source to Source or Sink to Sink. > > The DisplayPort driver currently checks for a compatible pin configuration > that resolves into a source and sink combination. The CTS test is designed > to send a Discover Modes message that has a compatible pin configuration > but advertises the same port capability as the device; the current check > fails this. > > Verify that the port and port partner resolve into a valid source and sink > combination before checking for a compatible pin configuration. > > --- > Changes since v1: > * Fixed styling errors > * Added DP_CAP_IS_UFP_D and DP_CAP_IS_DFP_D as macros to typec_dp.h > --- > > Fixes: 0e3bb7d6894d ("usb: typec: Add driver for DisplayPort alternate mode") > Cc: stable@vger.kernel.org > Signed-off-by: RD Babiera Acked-by: Heikki Krogerus > --- > drivers/usb/typec/altmodes/displayport.c | 5 +++++ > include/linux/usb/typec_dp.h | 2 ++ > 2 files changed, 7 insertions(+) > > diff --git a/drivers/usb/typec/altmodes/displayport.c b/drivers/usb/typec/altmodes/displayport.c > index 718da02036d8..9c17955da570 100644 > --- a/drivers/usb/typec/altmodes/displayport.c > +++ b/drivers/usb/typec/altmodes/displayport.c > @@ -578,6 +578,11 @@ int dp_altmode_probe(struct typec_altmode *alt) > > /* FIXME: Port can only be DFP_U. */ > > + /* Make sure that the port and partner can resolve into source and sink */ > + if (!(DP_CAP_IS_DFP_D(port->vdo) && DP_CAP_IS_UFP_D(alt->vdo)) && > + !(DP_CAP_IS_UFP_D(port->vdo) && DP_CAP_IS_DFP_D(alt->vdo))) > + return -ENODEV; > + > /* Make sure we have compatiple pin configurations */ > if (!(DP_CAP_PIN_ASSIGN_DFP_D(port->vdo) & > DP_CAP_PIN_ASSIGN_UFP_D(alt->vdo)) && > diff --git a/include/linux/usb/typec_dp.h b/include/linux/usb/typec_dp.h > index 1f358098522d..4e6c0479307f 100644 > --- a/include/linux/usb/typec_dp.h > +++ b/include/linux/usb/typec_dp.h > @@ -67,6 +67,8 @@ enum { > #define DP_CAP_UFP_D 1 > #define DP_CAP_DFP_D 2 > #define DP_CAP_DFP_D_AND_UFP_D 3 > +#define DP_CAP_IS_UFP_D(_cap_) (!!(DP_CAP_CAPABILITY(_cap_) & DP_CAP_UFP_D)) > +#define DP_CAP_IS_DFP_D(_cap_) (!!(DP_CAP_CAPABILITY(_cap_) & DP_CAP_DFP_D)) > #define DP_CAP_DP_SIGNALLING(_cap_) (((_cap_) & GENMASK(5, 2)) >> 2) > #define DP_CAP_SIGNALLING_HBR3 1 > #define DP_CAP_SIGNALLING_UHBR10 2 > > base-commit: 5220d8b04a840fa09434072c866d032b163419e3 > -- > 2.42.0.655.g421f12c284-goog -- heikki