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From: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
Date: Thu, 8 Feb 2024 20:35:17 -0800
Message-ID: <CANFp7mWz1cs3jwCHqf6Ku_RcQ6HmC9QHazoie=xxz8E6Rj2_QQ@mail.gmail.com>
Subject: Re: [PATCH v2 2/3] usb: typec: ucsi: Update connector cap and status
To: Jameson Thies <jthies@google.com>
Cc: Abhishek Pandit-Subedi <abhishekpandit@google.com>, 
	Heikki Krogerus <heikki.krogerus@linux.intel.com>, linux-usb@vger.kernel.org, 
	pmalani@chromium.org, Dmitry Baryshkov <dmitry.baryshkov@linaro.org>, 
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Neil Armstrong <neil.armstrong@linaro.org>, 
	Rajaram Regupathy <rajaram.regupathy@intel.com>, Saranya Gopal <saranya.gopal@intel.com>, 
	linux-kernel@vger.kernel.org
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On Thu, Feb 8, 2024 at 11:48=E2=80=AFAM Jameson Thies <jthies@google.com> w=
rote:
>
> Hi Abhishek,
>
> > +#define UCSI_CONCAP_FLAG_PARTNER_PD_MAJOR_REV_AS_BCD(_f_) \
> > +       (UCSI_CONCAP_FLAG_PARTNER_PD_MAJOR_REV(_f_) << 8)
>
> Can you replace this with a common HEADER_REV_AS_BCD macro that can be
> used for both GET_CONNECTOR_CAPABILTY and GET_CABLE_PROPERTY?
> Also, the USB PD major revision value in the message header is one less t=
han the
> revision (PD Spec section 6.2.1.1.5). So, we need to add 1 before shiftin=
g.

Jameson and I talked briefly and I discovered that PD assigns the
following values for the major rev:
* 00 =3D 1
* 01 =3D 2
* 10 =3D 3
* 11 =3D Reserved/Invalid

From PD 3 onwards, there's a new Get_Revision message that can be
queried from UCSI using GET_PD_MESSAGE. In future patches adding
support for Discover Identity (also using GET_PD_MESSAGE), we will
need to check this major revision to see whether we should also query
Get Revision.

Since this code is incorrect, I will send up a PATCH v4 with the
correct BCD version as Jameson suggested. I'll also fix up some of the
minor nits in that patch series.

>
> Thanks,
> Jameson