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=-3.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 01EE6C433E0 for ; Fri, 10 Jul 2020 03:28:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CED0F2065C for ; Fri, 10 Jul 2020 03:28:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="Y/MA9imF" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726818AbgGJD26 (ORCPT ); Thu, 9 Jul 2020 23:28:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54934 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726581AbgGJD25 (ORCPT ); Thu, 9 Jul 2020 23:28:57 -0400 Received: from mail-oi1-x244.google.com (mail-oi1-x244.google.com [IPv6:2607:f8b0:4864:20::244]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 87710C08C5DC for ; Thu, 9 Jul 2020 20:28:57 -0700 (PDT) Received: by mail-oi1-x244.google.com with SMTP id t4so3676207oij.9 for ; Thu, 09 Jul 2020 20:28:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=PKws9rr7OljHAXLs0SNBqV8l/zDxM95hYUjoVUcsLMw=; b=Y/MA9imFJwm2h1+DgPUYOn0x1e5bQqgU07Gi2iGRG/lwfvQkyoG/FtwR5qsp3do0Y3 yCR5Hps1LDqH/0O708Hck+CXWJXUW/Pm/dgq7jjaEfghm7v5/mSEHmBFS3fX0QNPYolf ubTdX550xKgLib4fyaBylbbUUSzyb38aG7zeVQdB5pSqjHMt+rsLG5JV2DsxNMdt1pvt KRMZPYM+vQpClcwdCxiSCTuFyS0F8maJbP2n3RriwfznlTAeWSdn7geAldubl/lrUFC4 me4dbcPDXLovepdNDGbrDCJ6PBJlAkPvR4QYNjXe2765EUymJkyyqOT78m+cxQYEziei SOYA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=PKws9rr7OljHAXLs0SNBqV8l/zDxM95hYUjoVUcsLMw=; b=i+1rj5VdKvtQp9ARTMUPIQ5mnlPdE7Cc3qE81IfBlnQI8ELls+LMa4kpxXS9BTrdPX sew8y4FnAgsm+3n8Y/QGQPleolgFsAgG7aXphVCqFDRfR9kwDrIrY8uHJ/jOCBEi2RSW ieJIXxq6IDDdpyvP2ZZwOJpOl5vhE1mYkseUSAvQP1yI5jro3H1c31Qsnkz8Jdb8IJ58 3abZh40X/+s+qlX+TqYZ5gSImWJPM6ioePhMquPvmMQFuLyrr9vo90wP53AhPnUN0UCc MbE15MA/JxUo4wLN/k2fOSdw/9Gz5+39niU/rkapsTUcr4KOvRJFp+6HWkE2hQ4VXeJo syxA== X-Gm-Message-State: AOAM5320x4mvOxtjxfyT0UIrkvSD+Vosscdv+RzIBJ0RuZP5yxxApFAu TVsRr2MI1+Q3gb5hj7ZLZ8Of8gDVidzg4bYKsqM+Y9Vb1NU= X-Google-Smtp-Source: ABdhPJwBCYPfCvq2KTarh+AoVyZD+95RmFXiFFqX0zZedcK0ojnQcCI1atRrtNfjUyY3XSL9F1IRdjivxmmz1/tlsLo= X-Received: by 2002:aca:b5c3:: with SMTP id e186mr2796817oif.10.1594351736777; Thu, 09 Jul 2020 20:28:56 -0700 (PDT) MIME-Version: 1.0 References: <20200625001039.56174-1-john.stultz@linaro.org> <20200625001039.56174-6-john.stultz@linaro.org> <20200702141825.GA16941@willie-the-truck> In-Reply-To: <20200702141825.GA16941@willie-the-truck> From: John Stultz Date: Thu, 9 Jul 2020 20:28:45 -0700 Message-ID: Subject: Re: [PATCH v2 5/5] firmware: QCOM_SCM: Allow qcom_scm driver to be loadable as a permenent module To: Will Deacon Cc: lkml , Andy Gross , Bjorn Andersson , Joerg Roedel , Thomas Gleixner , Jason Cooper , Marc Zyngier , Linus Walleij , Maulik Shah , Lina Iyer , Saravana Kannan , Todd Kjos , Greg Kroah-Hartman , linux-arm-msm , iommu@lists.linux-foundation.org, linux-gpio@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Sender: linux-gpio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org On Thu, Jul 2, 2020 at 7:18 AM Will Deacon wrote: > On Thu, Jun 25, 2020 at 12:10:39AM +0000, John Stultz wrote: > > diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig > > index b510f67dfa49..714893535dd2 100644 > > --- a/drivers/iommu/Kconfig > > +++ b/drivers/iommu/Kconfig > > @@ -381,6 +381,7 @@ config SPAPR_TCE_IOMMU > > config ARM_SMMU > > tristate "ARM Ltd. System MMU (SMMU) Support" > > depends on (ARM64 || ARM || (COMPILE_TEST && !GENERIC_ATOMIC64)) && MMU > > + depends on QCOM_SCM || !QCOM_SCM #if QCOM_SCM=m this can't be =y > > select IOMMU_API > > select IOMMU_IO_PGTABLE_LPAE > > select ARM_DMA_USE_IOMMU if ARM > > This looks like a giant hack. Is there another way to handle this? Sorry for the slow response here. So, I agree the syntax looks strange (requiring a comment obviously isn't a good sign), but it's a fairly common way to ensure drivers don't get built in if they optionally depend on another driver that can be built as a module. See "RFKILL || !RFKILL", "EXTCON || !EXTCON", or "USB_GADGET || !USB_GADGET" in various Kconfig files. I'm open to using a different method, and in a different thread you suggested using something like symbol_get(). I need to look into it more, but that approach looks even more messy and prone to runtime failures. Blocking the unwanted case at build time seems a bit cleaner to me, even if the syntax is odd. thanks -john