From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756625AbaIRKVX (ORCPT ); Thu, 18 Sep 2014 06:21:23 -0400 Received: from cantor2.suse.de ([195.135.220.15]:55940 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755755AbaIRKVV (ORCPT ); Thu, 18 Sep 2014 06:21:21 -0400 Date: Thu, 18 Sep 2014 12:21:20 +0200 Message-ID: From: Takashi Iwai To: Sudip Mukherjee Cc: Jaroslav Kysela , alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] sound: pci: ctxfi: pr_* replaced with dev_* In-Reply-To: <20140918092126.GA31651@sudip-PC> References: <1410790181-16457-1-git-send-email-sudipm.mukherjee@gmail.com> <20140915152554.GA26218@sudip-PC> <20140918092126.GA31651@sudip-PC> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI/1.14.6 (Maruoka) FLIM/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL/10.8 Emacs/24.3 (x86_64-suse-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org At Thu, 18 Sep 2014 14:51:26 +0530, Sudip Mukherjee wrote: > > On Mon, Sep 15, 2014 at 08:17:52PM +0200, Takashi Iwai wrote: > > At Mon, 15 Sep 2014 20:55:54 +0530, > > Sudip Mukherjee wrote: > > > > > > On Mon, Sep 15, 2014 at 04:29:48PM +0200, Takashi Iwai wrote: > > > > At Mon, 15 Sep 2014 19:39:41 +0530, > > > > Sudip Mukherjee wrote: > > > > > > > > > > > diff --git a/sound/pci/ctxfi/ctresource.c b/sound/pci/ctxfi/ctresource.c > > > > > index e49d2be..80beecb 100644 > > > > > --- a/sound/pci/ctxfi/ctresource.c > > > > > +++ b/sound/pci/ctxfi/ctresource.c > > > > (snip) > > > > > @@ -282,8 +287,9 @@ int rsc_mgr_uninit(struct rsc_mgr *mgr) > > > > > case SUM: > > > > > break; > > > > > default: > > > > > - pr_err("ctxfi: Invalid resource type value %d!\n", > > > > > - mgr->type); > > > > > + dev_err(&(((struct hw *)mgr->hw)->pci->dev), > > > > > + "ctxfi: Invalid resource type value %d!\n", > > > > > + mgr->type); > > > > > > > > Did you really conclude that this is the best way? > > > > Also, is it good to mix up the usages of both card->dev and &pci->dev? > > > > Think again. > > > > > > > > > > i have a doubt regarding this :- > > > in the snd_card_new() card->dev is being assigned with &pci->dev , > > > then are not they the same ? > > > > Yes, but how can it be guaranteed in future? We may avoid the > > problems in future by keeping the consistency at this moment. It's > > one of the good points of keeping code consistent, in addition to: > > increased readability / understandability and making the bug easier to > > be spotted. > > understood the point. > > > > > i was trying to get some way of finding out the reference of card->dev from the resource manager , > > > but ... :( > > > i will try again and if i cant find any way i will ask for some hint from you. > > > > Good! A hint is that there is no 100% perfect way to achieve this. > > It's always compromise, and you'll have to choose which one is better > > than others. For that, you'll have to evaluate multiple > > implementations, and it's a really good exercise for coding. > > > > i can find the rsc_mgr from the snd_card or ct_atc > but if i want to find the reference to the device from the managers , then > either i can go with > 1) &(((struct hw *)mgr->hw)->pci->dev) > or > 2) use pci_get_drvdata with ((struct hw *)mgr->hw)->pci > or > 3) using container_of with &(((struct hw *)mgr->hw)->pci->dev) to find the pointer to snd_card via card_dev , but it becomes too complicated :( > > we can get to all the managers (rsc_mgr, amixer_mgr, src_mgr ...) using atc->rsc_mgrs[] , then there should be some simple way to go > the opposite way (reaching atc from the managers) . container_of will not work .. :( > or am i missing something?? Adding a new field pointing to card to each struct. Takashi