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 X-Spam-Level: X-Spam-Status: No, score=-5.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BC092C4363D for ; Tue, 20 Oct 2020 14:13:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 57DF62224F for ; Tue, 20 Oct 2020 14:13:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="XFRswQp4" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2407931AbgJTONk (ORCPT ); Tue, 20 Oct 2020 10:13:40 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:45167 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2407926AbgJTONj (ORCPT ); Tue, 20 Oct 2020 10:13:39 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1603203218; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=R16EbEDXYLBuqh4nIdDbRp7O0oRY2wnv3lXnFRIbqKI=; b=XFRswQp4/zXOXJyqNLYjXAGHiIgOZ6vHdBYyP5Y7Xw8h+xFOwyu0r88s5v1vqhrvyd21Z5 wjBbqCL+z/0uA1TZdfbX9NtaSrVYi1ND2PKpYKPeo+iZQDR3OvrAPFZUgTUmbNI3dRo5bf ernnHQ0I/8pavyxjrjlPviwJb2dCtnE= Received: from mail-qv1-f70.google.com (mail-qv1-f70.google.com [209.85.219.70]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-170-FHT61r7qPqKo-a9wwil6ow-1; Tue, 20 Oct 2020 10:13:35 -0400 X-MC-Unique: FHT61r7qPqKo-a9wwil6ow-1 Received: by mail-qv1-f70.google.com with SMTP id t13so1438297qvm.14 for ; Tue, 20 Oct 2020 07:13:34 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding :content-language; bh=R16EbEDXYLBuqh4nIdDbRp7O0oRY2wnv3lXnFRIbqKI=; b=MeL9aLTTX4BNewr4rd9E/zmv/1TIO8GFI0LMy+2AuDTZUN5nfS5SA3ADWqNIL6SaQ1 q7yjSYzMkjfA4TjIYVb4xw363Z7gsUD7hPu/85yndJymGgVWBCb1PLPLQ9IYcWsd9ISV TohRlIO6EPGz6PshALMBgqVS5CUOes73KGeEZD9y7yhsqh3V8tgrxFyeMtL7bsomNdjJ 8s17EMKVMg7ZwrM77QETEKz3nIC0F0rRmbIb3aPeDM0JxLnArM3JsEG8rHm8pVCYN1H4 F64efyMR4v01gCsZNjIE1JDHzRq+g7LOSsN1bmC6gvwFNmywky7urE4J39+OwYeVS3dN FC6g== X-Gm-Message-State: AOAM533dBalpAmUn5KM/OYgV8n8/5votTnprCbiyhvnfsdWG42+XbJOa 4wEEOYtLcePHCjmMAVhzhFSe00OYmQcmS7HYWLFkEW08LH5P7V6/AEJcRLz+5MK5kx2dnutExbQ cyrfbnQat/21SeN6ojsDySMkp X-Received: by 2002:a37:4244:: with SMTP id p65mr994615qka.141.1603203214566; Tue, 20 Oct 2020 07:13:34 -0700 (PDT) X-Google-Smtp-Source: ABdhPJz+u0NYgPuykSbBGly8cM+QOe6I8vZ8CSK1Vl+thq2i8Y9RMNBefXkQTQxBeCh/pM8txDvIng== X-Received: by 2002:a37:4244:: with SMTP id p65mr994602qka.141.1603203214330; Tue, 20 Oct 2020 07:13:34 -0700 (PDT) Received: from trix.remote.csb (075-142-250-213.res.spectrum.com. [75.142.250.213]) by smtp.gmail.com with ESMTPSA id e19sm806862qkl.94.2020.10.20.07.13.32 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 20 Oct 2020 07:13:33 -0700 (PDT) Subject: Re: [PATCH 1/2] fpga: dfl: add driver_override support To: Xu Yilun Cc: mdf@kernel.org, linux-fpga@vger.kernel.org, linux-kernel@vger.kernel.org, gregkh@linuxfoundation.org, lgoncalv@redhat.com, hao.wu@intel.com References: <1602828151-24784-1-git-send-email-yilun.xu@intel.com> <1602828151-24784-2-git-send-email-yilun.xu@intel.com> <63d7730b-d9b8-c75d-16f6-3ebb507aabaa@redhat.com> <20201019040612.GA16172@yilunxu-OptiPlex-7050> <20201020071158.GC28746@yilunxu-OptiPlex-7050> From: Tom Rix Message-ID: <48cc1b5f-4bb1-260d-7b8b-9484d3f0a6ba@redhat.com> Date: Tue, 20 Oct 2020 07:13:31 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.6.0 MIME-Version: 1.0 In-Reply-To: <20201020071158.GC28746@yilunxu-OptiPlex-7050> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/20/20 12:11 AM, Xu Yilun wrote: >>>>> int __dfl_driver_register(struct dfl_driver *dfl_drv, struct module *owner) >>>>> { >>>>> - if (!dfl_drv || !dfl_drv->probe || !dfl_drv->id_table) >>>>> + if (!dfl_drv || !dfl_drv->probe) >>>> id_table is still needed for the normal case. >>>> >>>> Instead of removing this check, could you add something like >>>> >>>> || (!dfl_drv->is_override && !dfl_drv->id_table) >>> I don't think it is needed. Seems is_override and !id_table are duplicated >>> conditions for this implementation. And it may make confusing, e.g. could >>> a driver been force matched when is_override is not set? >>> >>> I think we could make it simple, if the dfl driver didn't provide the >>> id_table, normally it could not match any device. I think it could be >>> easily understood by dfl driver developers. >>> >> Then an ASSERT should be added in dfl_bus_match() for id_entry. > I didn't get your idea. What Assertion should be added for id_entry? > BUG_ON(id_entry == NULL)? Then dfl-uio-pdev can't be inserted before > driver_override is set. > > I think it is normal case that a driver is successfully registered but > doesn't match any device because it provides no id_table. Ok, i see your point. Thanks for the explanation. Tom > > Thanks, > Yilun. >