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 22DE4C4332F for ; Wed, 18 May 2022 12:01:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236085AbiERMBx (ORCPT ); Wed, 18 May 2022 08:01:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57136 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236358AbiERMB1 (ORCPT ); Wed, 18 May 2022 08:01:27 -0400 Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [46.235.227.227]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1AECB23177; Wed, 18 May 2022 05:01:25 -0700 (PDT) Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: kholk11) with ESMTPSA id 593BF1F44F9A DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1652875283; bh=eWMO+9i9voS89Q+F8+40P0pUsammpGTwWoyawgM0xNg=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=Lhm/J/hXfAJ9BJFEvYcRwETBoCLYtJjqJQQ0KCGtbdsJBYbfPgAYbZjaq8Cktb2GQ jnnvBMRi1Fp5XaQ2ARbA3DD3le7L828QOMEJVDVoyrihhnf3NecPbVjmBhdIfXSwql xlrpC5xyXxPJaYxbqz6mrtWM0QPP/VKPqKdlpvmF2aF4rgAA0/w4E0Tb3TBlaavlV6 b/IMu1+Fp88Ur8Z3WPojwmmsa1Sv4FPuY0E0DTUVifvIHLCXJLW04LoD2492ptn0xp lUjkeb67qxETH++3Y3SNfRaTNO+0MSwXP/bF2VPqbwUUuRB31FyZCtYBkXOvolkJCf 4gz0tsNkszGug== Message-ID: <7781eaaf-ad09-7283-dbb8-69d0fb3f1d14@collabora.com> Date: Wed, 18 May 2022 14:01:20 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.9.0 Subject: Re: [PATCH 1/2] usb: xhci-mtk: fix fs isoc's transfer error Content-Language: en-US To: Chunfeng Yun , Greg Kroah-Hartman Cc: Mathias Nyman , Matthias Brugger , linux-usb@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org, Eddie Hung , Tianping Fang , stable@vger.kernel.org References: <20220512064931.31670-1-chunfeng.yun@mediatek.com> From: AngeloGioacchino Del Regno In-Reply-To: <20220512064931.31670-1-chunfeng.yun@mediatek.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Il 12/05/22 08:49, Chunfeng Yun ha scritto: > Due to the scheduler allocates the optimal bandwidth for FS ISOC endpoints, > this may be not enough actually and causes data transfer error, so come up > with an estimate that is no less than the worst case bandwidth used for > any one mframe, but may be an over-estimate. > > Fixes: 451d3912586a ("usb: xhci-mtk: update fs bus bandwidth by bw_budget_table") > Cc: stable@vger.kernel.org > Signed-off-by: Chunfeng Yun Hello Chunfeng, I agree this is "a fix"... but is it the best fix? Shooting the bandwidth very high will have power consumption consequences, are those measurable? And if they are, what is the expected power consumption increase in percentage (and/or microamperes)? Also, out of the expected increase, have you got any measurement for that? Assuming that the measurement is done for one SoC, it's possible to make some assumption about a different part. Regards, Angelo > --- > drivers/usb/host/xhci-mtk-sch.c | 16 +++++++--------- > 1 file changed, 7 insertions(+), 9 deletions(-) > > diff --git a/drivers/usb/host/xhci-mtk-sch.c b/drivers/usb/host/xhci-mtk-sch.c > index f3139ce7b0a9..953d2cd1d4cc 100644 > --- a/drivers/usb/host/xhci-mtk-sch.c > +++ b/drivers/usb/host/xhci-mtk-sch.c