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=-3.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 BFE6BC10F27 for ; Tue, 10 Mar 2020 10:14:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 95D4220637 for ; Tue, 10 Mar 2020 10:14:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="g8ZD6JIS" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726199AbgCJKOH (ORCPT ); Tue, 10 Mar 2020 06:14:07 -0400 Received: from mail-lf1-f65.google.com ([209.85.167.65]:40729 "EHLO mail-lf1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726244AbgCJKOH (ORCPT ); Tue, 10 Mar 2020 06:14:07 -0400 Received: by mail-lf1-f65.google.com with SMTP id j17so5821494lfe.7; Tue, 10 Mar 2020 03:14:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=H41EK6fFWsu7lc3SctFKC6jvmteBRlGuxbpCpld6vno=; b=g8ZD6JIS5Nbi5VQkoVKI9M/R0asumknvg+5tJnMpLTrwLqopBa459G+Q/XQzcwPv1A dnFXMhqtT5oJqRaM0Kwk034c0qEj7/G4f0UyF3vC+FunNgutepJnWbUIIsGWNMpGPrij jCA2K6vv24K2GdNo8Kj6muOUhaj5wLjo7+xZTE36a18WvipB2aBXdQTWg0csU9DCnIdr zMRrnaF4sdNWdxAyrCOzLDh60CE54BVAevIoJBTwsg102Mg3I3iWoDVg8tiNJ8LskBgt 3Uik+QIPptsu2Tb68aLInTso3Nwoo+3e8nPPA+WZWFbBl4GCkwQ4O6CZhst/1TtrprRx aaXw== 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=H41EK6fFWsu7lc3SctFKC6jvmteBRlGuxbpCpld6vno=; b=hWR5rykeIlqbSGtI2aeckCYNP3m4mdHHaCugsc7Zle8BbfH6WG/bL+EgPgdmMBSmRY UOL8UfnYyUi7G8+3hM4topFjO6EF6seuJVwXGpDDuQMk3NjZpm+6PLAzJ5ch9nVfgx4z BKSYiZIfRfdj5Ri++KZJD+9bgn4PfufS44lUXLiR+a9KgKMPXJhBWJsowxddkuWk6YD+ Pw65yTaDBBVBzPTXtDp2C3Qv4sKIjVHDF8DZZWfWIbfysVW28AbeXEmad8n3Tt1Dcalw KPWqWD/tbRGf6n2DKKqzqDF3QW1Ivch7TF/NaP0i08QdNzuHWAyMezgPmx+jK0MkJm3e LXNA== X-Gm-Message-State: ANhLgQ0jRLhnM1E9H+szgp4wURDOQmJOF22mnIOQ1m58Motg3sWgTEnQ kBF2VIZ/DU6b5lmvq+sNXZvEOHoHCiQNHZGnCWU= X-Google-Smtp-Source: ADFU+vsQgLEAeKs3QBpJxub3atlz11c+n+Pl9FnwgZlDHA1wgeUPgTtZl/KRIlugnXJikY9VrxzECcYh0hftZrqU0oQ= X-Received: by 2002:a19:f615:: with SMTP id x21mr325697lfe.47.1583835244537; Tue, 10 Mar 2020 03:14:04 -0700 (PDT) MIME-Version: 1.0 References: <20200305103228.9686-1-zhang.lyra@gmail.com> In-Reply-To: From: Orson Zhai Date: Tue, 10 Mar 2020 18:13:51 +0800 Message-ID: Subject: Re: [PATCH 1/2] arm64: change ARCH_SPRD Kconfig to tristate To: Geert Uytterhoeven Cc: Chunyan Zhang , Greg Kroah-Hartman , Catalin Marinas , Will Deacon , Jiri Slaby , Linux Kernel Mailing List , Chunyan Zhang , "open list:SERIAL DRIVERS" , Baolin Wang , Linux ARM , Android Kernel Team Content-Type: text/plain; charset="UTF-8" Sender: linux-serial-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org On Tue, Mar 10, 2020 at 5:52 PM Geert Uytterhoeven wrote: > > Hi Orson, > > On Tue, Mar 10, 2020 at 10:41 AM Orson Zhai wrote: > > On Mon, Mar 9, 2020 at 6:32 PM Geert Uytterhoeven wrote: > > > On Mon, Mar 9, 2020 at 9:32 AM Chunyan Zhang wrote: > > > > On Mon, 9 Mar 2020 at 16:03, Geert Uytterhoeven wrote: > > > > > On Thu, Mar 5, 2020 at 11:33 AM Chunyan Zhang wrote: > > > > > > From: Chunyan Zhang > > > > > > > > > > > > The default value of Kconfig for almost all sprd drivers are the same with > > > > > > ARCH_SPRD, making these drivers built as modules as default would be easier > > > > > > if we can set ARCH_SPRD as 'm', so this patch change ARCH_SPRD to tristate. > > > > > > > > > > > > Signed-off-by: Chunyan Zhang > > > > > > > > > > Can you actually boot a kernel on a Spreadtrum platform when all platform > > > > > and driver support is modular? > > > > > > > > Yes, even if all drivers are modular. > > > > > > Cool. No hard dependencies on e.g. regulators that are turned off when > > > unused? > > > > > > > But I hope serial can be builtin, then I can have a console to see > > > > kernel output before loading modules. > > > > > > No dependency on the clock driver? > > > Oh, I see you have a hack in the serial driver, to assume default > > > values when the serial port's parent clock is not found. That may > > > limit use of the other serial ports, depending on the actual serial > > > hardware. > > > > There is an function named "sprd_uart_is_console()" in the driver > > code. So the hack could be only applied when the > > port is identified as console. And other ports might return > > PROBE_DEFER until the clock is ready. > > > > Could it work out of the limitation? > > Yes, that could work. You also have only a single SPRD_DEFAULT_SOURCE_CLK, > which makes it simple to handle. > For other SoCs, there may be a variation of possible values, depending on > SoC and/or board. Ok, thanks. -Orson > > Gr{oetje,eeting}s, > > Geert > > -- > Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org > > In personal conversations with technical people, I call myself a hacker. But > when I'm talking to journalists I just say "programmer" or something like that. > -- Linus Torvalds