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 0ADA6C001DF for ; Wed, 2 Aug 2023 06:57:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231726AbjHBG5u (ORCPT ); Wed, 2 Aug 2023 02:57:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49824 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231859AbjHBG5s (ORCPT ); Wed, 2 Aug 2023 02:57:48 -0400 Received: from mail-ed1-x52d.google.com (mail-ed1-x52d.google.com [IPv6:2a00:1450:4864:20::52d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ADA391FF3 for ; Tue, 1 Aug 2023 23:57:25 -0700 (PDT) Received: by mail-ed1-x52d.google.com with SMTP id 4fb4d7f45d1cf-5222bc91838so9479187a12.0 for ; Tue, 01 Aug 2023 23:57:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=resnulli-us.20221208.gappssmtp.com; s=20221208; t=1690959444; x=1691564244; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=HB8Dw00DZJ09mEmQijXfQQXA6sfh5AwCygh3j6F8AMc=; b=lSzUBF6FWUxiw1oYdULIQmYbEwENFVJmgp4JHBGx1zI7B5KvQ4m1+HYCR3R505SGO+ Slnm+NLgpdt03o6b0L5LjdOksh6iuX/NfrVTmTR1r3wSyzLm1ZvZhs8JTUP/R0HGnXbt +dId+PmCsdS9AeXUfXfuzB7uBR58pYzFlr4jLqg6SD6WkBW0X7fzWbq6Ap51X5SrY7f8 26Rfid8Vp4WklhfLbP86W/a8mULDm3JgxVAUpRVulNg8v5IMCFqe9SbxU29Q2s2n5LbS BJ3qf3Q9gDvbLHRTwsNp/N0vzDrst27eU4f2XDPFe7aEPvC8jqnd3eLXFIifyDzPf3/W 8l9A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1690959444; x=1691564244; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=HB8Dw00DZJ09mEmQijXfQQXA6sfh5AwCygh3j6F8AMc=; b=JNCwOeJwfFEGePEWyunq1yadi4dpok10JS4gOPZNDQYkcgURgUCRUnm6vfk98eyBX5 aPZIxt0qeOBrmlGcW4Yk0Wdx242h7xZGNpoAGDcyDIveoVOswwS7xHFi/3MHWrLjpIc6 tforkfkahPXAOYrkjMAPbhbKl/f6JWMo4YtuqfZKOgrAK/yyVFPA7cjqJbnrRFsi/M4t yzOJlGv0J3O3Z4ow0mvMmamU9hB5GfR2Y1PpILt8YKXB7uNcpVG7oigjcWferUCoZRyM lOvgZ67ujWyuIwWIa+dTNhNj9y3XZ3cPZxqF37wqdujKO5UXdd/dDeFoxvCBq/XT3UaI 5Dgg== X-Gm-Message-State: ABy/qLbpuxV4Awo5xpQoBgZi8RVfODyarcOQIiJdFj/JgsH2kIFtCWqF ngb8tvqph/2DdDLlyd6RUyMllA== X-Google-Smtp-Source: APBJJlGatQfPGX1zCA4O2oVLRP7VUG8QpcwUx9/zHINaPrjjZYEd6cJWoVD2Oc2hkHgdGZY7lcZQvQ== X-Received: by 2002:a17:906:3198:b0:98e:1156:1a35 with SMTP id 24-20020a170906319800b0098e11561a35mr3703590ejy.74.1690959444201; Tue, 01 Aug 2023 23:57:24 -0700 (PDT) Received: from localhost ([212.23.236.67]) by smtp.gmail.com with ESMTPSA id mb5-20020a170906eb0500b00997cce73cc7sm8598409ejb.29.2023.08.01.23.57.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 01 Aug 2023 23:57:23 -0700 (PDT) Date: Wed, 2 Aug 2023 08:57:22 +0200 From: Jiri Pirko To: "Kubalewski, Arkadiusz" Cc: Vadim Fedorenko , Jakub Kicinski , Jonathan Lemon , Paolo Abeni , "Olech, Milena" , "Michalik, Michal" , "linux-arm-kernel@lists.infradead.org" , poros , mschmidt , "netdev@vger.kernel.org" , "linux-clk@vger.kernel.org" , Bart Van Assche Subject: Re: [PATCH 09/11] ice: implement dpll interface to control cgu Message-ID: References: <20230720091903.297066-1-vadim.fedorenko@linux.dev> <20230720091903.297066-10-vadim.fedorenko@linux.dev> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-clk@vger.kernel.org Tue, Aug 01, 2023 at 04:50:44PM CEST, arkadiusz.kubalewski@intel.com wrote: >>From: Jiri Pirko >>Sent: Monday, July 31, 2023 2:20 PM >> >>Sat, Jul 29, 2023 at 01:03:59AM CEST, arkadiusz.kubalewski@intel.com wrote: >>>>From: Jiri Pirko >>>>Sent: Friday, July 21, 2023 1:39 PM >>>> >>>>Thu, Jul 20, 2023 at 11:19:01AM CEST, vadim.fedorenko@linux.dev wrote: >>>>>From: Arkadiusz Kubalewski >>> >> >>[...] >> >> >>>>>+static int ice_dpll_cb_lock(struct ice_pf *pf, struct netlink_ext_ack >>>>>*extack) >>>>>+{ >>>>>+ int i; >>>>>+ >>>>>+ for (i = 0; i < ICE_DPLL_LOCK_TRIES; i++) { >>>>>+ if (!test_bit(ICE_FLAG_DPLL, pf->flags)) { >>>> >>>>And again, as I already told you, this flag checking is totally >>>>pointless. See below my comment to ice_dpll_init()/ice_dpll_deinit(). >>>> >>> >>>This is not pointless, will explain below. >>> >>>> >>>> >>> >>>[...] >>> >> >>[...] >> >> >>>>>+void ice_dpll_deinit(struct ice_pf *pf) >>>>>+{ >>>>>+ bool cgu = ice_is_feature_supported(pf, ICE_F_CGU); >>>>>+ >>>>>+ if (!test_bit(ICE_FLAG_DPLL, pf->flags)) >>>>>+ return; >>>>>+ clear_bit(ICE_FLAG_DPLL, pf->flags); >>>>>+ >>>>>+ ice_dpll_deinit_pins(pf, cgu); >>>>>+ ice_dpll_deinit_dpll(pf, &pf->dplls.pps, cgu); >>>>>+ ice_dpll_deinit_dpll(pf, &pf->dplls.eec, cgu); >>>>>+ ice_dpll_deinit_info(pf); >>>>>+ if (cgu) >>>>>+ ice_dpll_deinit_worker(pf); >>>> >>>>Could you please order the ice_dpll_deinit() to be symmetrical to >>>>ice_dpll_init()? Then, you can drop ICE_FLAG_DPLL flag entirely, as the >>>>ice_dpll_periodic_work() function is the only reason why you need it >>>>currently. >>>> >>> >>>Not true. >>>The feature flag is common approach in ice. If the feature was successfully >> >>The fact that something is common does not necessarily mean it is >>correct. 0 value argument. >> > >Like using functions that unwrap netlink attributes as unsigned when >they are in fact enums with possibility of being signed? Looks this is bothering you, sorry about that. > >This is about consistent approach in ice driver. > >> >>>initialized the flag is set. It allows to determine if deinit of the feature >>>is required on driver unload. >>> >>>Right now the check for the flag is not only in kworker but also in each >>>callback, if the flag were cleared the data shall be not accessed by >>>callbacks. >> >>Could you please draw me a scenario when this could actually happen? >>It is just a matter of ordering. Unregister dpll device/pins before you >>cleanup the related resources and you don't need this ridiculous flag. >> > >Flag allows to determine if dpll was successfully initialized and do proper >deinit on rmmod only if it was initialized. That's all. You are not answering my question. I asked about how the flag helps is you do unregister dpll devices/pins and you free related resources in the correct order. Because that is why you claim you need this flag. I'm tired of this. Keep your driver tangled for all I care, I'm trying to help you, obviously you are not interested. > >> >>>I know this is not required, but it helps on loading and unloading the >>>driver, >>>thanks to that, spam of pin-get dump is not slowing the driver >>>load/unload. >> >>? Could you plese draw me a scenario how such thing may actually happen? > >First of all I said it is not required. > >I already draw you this with above sentence. >You need spam pin-get asynchronously and unload driver, what is not clear? >Basically mutex in dpll is a bottleneck, with multiple requests waiting for >mutex there is low change of driver getting mutex when doing unregisters. How exactly your flag helps you in this scenario? It does not. > >We actually need to redesign the mutex in dpll core/netlink, but I guess after >initial submission. Why? > >Thank you! >Arkadiusz > >> >>Thanks! >> >> >>> >>>> >>>>>+ mutex_destroy(&pf->dplls.lock); >>>>>+} >> >> >>[...]