Received: by 2002:a05:6358:f14:b0:e5:3b68:ec04 with SMTP id b20csp6240526rwj; Wed, 21 Dec 2022 12:40:53 -0800 (PST) X-Google-Smtp-Source: AMrXdXtdCAHKrXUkacCC6wXzWa+DeADqkrxqGMedXSnOOhAZWs6vFRA7ScKS6pnbIRU13Z01W60g X-Received: by 2002:a17:907:d50e:b0:7c1:5982:d729 with SMTP id wb14-20020a170907d50e00b007c15982d729mr6575076ejc.56.1671655253498; Wed, 21 Dec 2022 12:40:53 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1671655253; cv=none; d=google.com; s=arc-20160816; b=cs65O0CSKyWWABtPGx2vkXKiaTMvGQF2InE9u4SE025xBXgpTXN2/CTgdtReGD5aSE IV7uLDWwCmCoaB3bsakezrp933IFM/Zim80MEDispvqdLNdrh1WDe8a2z04zHgeHCTed BS+MUTUCb0AB2g0jmZUQZSa6FOe+TaoNRssuE3YmlimXsiuUVTeZP1/SEQpKlrAB2P/u FUaVetfmJ/lxTuw/6Q2fvsb7kGCmViF+cFR5kzA2DPSrX6FeqzsF8B9GGaVlInd5pT1Q xOy1yJy5lTrZB8ahAumhA7ejirGSMRFyx8R66tjRx2gz5mZJbXFOxvnXHkrPjp5mliCQ 7HPA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:in-reply-to:content-disposition:mime-version :references:message-id:subject:cc:to:from:date; bh=S7DRrS8P7vCa1MYwN+5bVVG0pF6co7/snumIjHpmVug=; b=EIjoXQbTRJUPhy7jYkZScZAKga68V2MJSlNTjrmEXyCoVlapYtYlP8riGBwhWo3Wd8 xxpYWLF6tBV8elc94VxTLRznAK4L9ywu7xJwL5XJYqckeIIxpg7qE2OgilvwPfRSs0jN PNyc6nxwdsczSkxOC+jJwhIW/lM3x1v+esAAPGgunwzNUL7y6MXOf1R4V4Dy2ekPaQQX 2AywCc2jhXugHJQrABcXJLmBuvcYMppKc6JqXuzx6KVO1NQ8kq8pval3ahIhapfJ4CHY OXZqhchAGzn3VB/9MPQQC91PiufXkHxwPdg5Jj7WZz794JuAAFO5iMmQOWzknogfQbsm kEig== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id hb11-20020a170907160b00b007822665aa36si16732844ejc.430.2022.12.21.12.40.36; Wed, 21 Dec 2022 12:40:53 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234833AbiLUU1Y (ORCPT + 68 others); Wed, 21 Dec 2022 15:27:24 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58422 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229844AbiLUU1W (ORCPT ); Wed, 21 Dec 2022 15:27:22 -0500 Received: from netrider.rowland.org (netrider.rowland.org [192.131.102.5]) by lindbergh.monkeyblade.net (Postfix) with SMTP id 909EB24F23 for ; Wed, 21 Dec 2022 12:27:21 -0800 (PST) Received: (qmail 100059 invoked by uid 1000); 21 Dec 2022 15:27:20 -0500 Date: Wed, 21 Dec 2022 15:27:20 -0500 From: Alan Stern To: Ricardo Ribalda Cc: Greg Kroah-Hartman , Bagas Sanjaya , Christoph Hellwig , linux-kernel@vger.kernel.org, Laurent Pinchart , Randy Dunlap , linux-usb@vger.kernel.org Subject: Re: [PATCH v4] USB: Improve usb_fill_* documentation Message-ID: References: <20221220-usb-dmadoc-v4-0-74a045bf14f4@chromium.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221220-usb-dmadoc-v4-0-74a045bf14f4@chromium.org> X-Spam-Status: No, score=-1.7 required=5.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,SPF_HELO_PASS,SPF_PASS autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Dec 21, 2022 at 08:34:51PM +0100, Ricardo Ribalda wrote: > Document the transfer buffer requirement. That is, the buffer must be > DMAble - otherwise data corruption might occur. > > Acked-by: Randy Dunlap > Reviewed-by: Laurent Pinchart > Signed-off-by: Ricardo Ribalda > --- > USB: Improve usb_fill_* documentation > > After trying to "cleanup" the uvc code, I was patiently explained about > the requirements of the urb transfer buffers. > > Lets make this explicit, so other developers do not make the same mistake. > > To: Bagas Sanjaya > To: Randy Dunlap > To: Alan Stern > To: Christoph Hellwig > To: Laurent Pinchart > To: Greg Kroah-Hartman > Cc: linux-usb@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > --- Acked-by: Alan Stern