Return-path: Received: from smtp.codeaurora.org ([198.145.29.96]:56268 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752360AbdLDOrD (ORCPT ); Mon, 4 Dec 2017 09:47:03 -0500 From: Kalle Valo To: Sergey Matyukevich Cc: linux-wireless@vger.kernel.org, Igor Mitsyanko , Avinash Patil , Vasily Ulyanov Subject: Re: [PATCH 02/10] qtnfmac: pass complete channel data between driver and firmware References: <20171113102815.11254-1-sergey.matyukevich.os@quantenna.com> <20171113102815.11254-3-sergey.matyukevich.os@quantenna.com> Date: Mon, 04 Dec 2017 16:46:59 +0200 In-Reply-To: <20171113102815.11254-3-sergey.matyukevich.os@quantenna.com> (Sergey Matyukevich's message of "Mon, 13 Nov 2017 13:28:07 +0300") Message-ID: <87efoalfdo.fsf@purkki.adurom.net> (sfid-20171204_154707_749238_ABAD6607) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-wireless-owner@vger.kernel.org List-ID: Sergey Matyukevich writes: > Center frequency is not enough to describe the channel in HT and VHT > modes. For 40MHz and 80MHz channels both primary channel and center > frequency should be specified in order to qualify channel completely. > This change adds primary channel info into qlink_chandef structure. > > Signed-off-by: Sergey Matyukevich [...] > +/** > * struct qlink_chandef - qlink channel definition > * > + * @chan: primary channel definition > * @center_freq1: center frequency of first segment > * @center_freq2: center frequency of second segment (80+80 only) > * @width: channel width, one of @enum qlink_channel_width > */ > struct qlink_chandef { > + struct qlink_channel chan; > __le16 center_freq1; > __le16 center_freq2; > u8 width; > - u8 rsvd[3]; > + u8 rsvd; > } __packed; Doesn't this break backwards compatibility with the older firmware? The basic princinple is that old firmware images continue to work with newer driver (or there will be a firmware image with new name, eg. fw-2.bin). You can check how iwlwifi does that. As this is a new driver I guess it doesn't matter that much to break it, but please keep this in mind in the future. -- Kalle Valo