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=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=ham 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 F3635C54FD0 for ; Thu, 23 Apr 2020 16:59:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D561120781 for ; Thu, 23 Apr 2020 16:59:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729757AbgDWQ7q (ORCPT ); Thu, 23 Apr 2020 12:59:46 -0400 Received: from foss.arm.com ([217.140.110.172]:44306 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729687AbgDWQ7q (ORCPT ); Thu, 23 Apr 2020 12:59:46 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 51C0530E; Thu, 23 Apr 2020 09:59:45 -0700 (PDT) Received: from bogus (unknown [10.37.12.118]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 017993F68F; Thu, 23 Apr 2020 09:59:40 -0700 (PDT) Date: Thu, 23 Apr 2020 17:58:47 +0100 From: Sudeep Holla To: Rob Herring Cc: Linus Walleij , Liviu Dudau , Lorenzo Pieralisi , Arnd Bergmann , Catalin Marinas , Greg Kroah-Hartman , Lee Jones , Sebastian Reichel , Stephen Boyd , Will Deacon , Sudeep Holla , Kevin Brodsky , "moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE" , linux-clk , "open list:THERMAL" , Michael Turquette Subject: Re: [PATCH 08/17] clk: vexpress-osc: Support building as a module Message-ID: <20200423165847.GA19124@bogus> References: <20200419170810.5738-1-robh@kernel.org> <20200419170810.5738-9-robh@kernel.org> <20200422210802.GH25585@bogus> <20200423133342.GA10628@bogus> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-clk-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-clk@vger.kernel.org On Thu, Apr 23, 2020 at 10:53:40AM -0500, Rob Herring wrote: > On Thu, Apr 23, 2020 at 8:45 AM Sudeep Holla wrote: > > > > On Wed, Apr 22, 2020 at 10:08:02PM +0100, Sudeep Holla wrote: > > > On Sun, Apr 19, 2020 at 12:08:01PM -0500, Rob Herring wrote: > > > > Enable building the vexpress-osc clock driver as a module. > > > > > > > > Cc: Linus Walleij > > > > Cc: Liviu Dudau > > > > Cc: Sudeep Holla > > > > Cc: Lorenzo Pieralisi > > > > Cc: Michael Turquette > > > > Cc: Stephen Boyd > > > > Cc: linux-clk@vger.kernel.org > > > > Signed-off-by: Rob Herring > > > > --- > > > > drivers/clk/versatile/Kconfig | 4 ++-- > > > > drivers/clk/versatile/clk-vexpress-osc.c | 10 ++++------ > > > > 2 files changed, 6 insertions(+), 8 deletions(-) > > > > > > > > diff --git a/drivers/clk/versatile/Kconfig b/drivers/clk/versatile/Kconfig > > > > index 5bdd5c98990b..9de2396dcf9b 100644 > > > > --- a/drivers/clk/versatile/Kconfig > > > > +++ b/drivers/clk/versatile/Kconfig > > > > @@ -15,8 +15,8 @@ config CLK_SP810 > > > > of the ARM SP810 System Controller cell. > > > > > > > > config CLK_VEXPRESS_OSC > > > > - bool "Clock driver for Versatile Express OSC clock generators" > > > > - depends on VEXPRESS_CONFIG || COMPILE_TEST > > > > + tristate "Clock driver for Versatile Express OSC clock generators" > > > > + depends on VEXPRESS_CONFIG > > > > default y if ARCH_VEXPRESS > > > > ---help--- > > > > Simple regmap-based driver driving clock generators on Versatile > > > > diff --git a/drivers/clk/versatile/clk-vexpress-osc.c b/drivers/clk/versatile/clk-vexpress-osc.c > > > > index 5bb1d5a714d0..b2b32fa2d7c3 100644 > > > > --- a/drivers/clk/versatile/clk-vexpress-osc.c > > > > +++ b/drivers/clk/versatile/clk-vexpress-osc.c > > > > @@ -7,6 +7,7 @@ > > > > #include > > > > #include > > > > #include > > > > +#include > > > > #include > > > > #include > > > > #include > > > > @@ -108,6 +109,7 @@ static const struct of_device_id vexpress_osc_of_match[] = { > > > > { .compatible = "arm,vexpress-osc", }, > > > > {} > > > > }; > > > > +MODULE_DEVICE_TABLE(of, vexpress_osc_of_match); > > > > > > > > static struct platform_driver vexpress_osc_driver = { > > > > .driver = { > > > > @@ -116,9 +118,5 @@ static struct platform_driver vexpress_osc_driver = { > > > > }, > > > > .probe = vexpress_osc_probe, > > > > }; > > > > - > > > > -static int __init vexpress_osc_init(void) > > > > -{ > > > > - return platform_driver_register(&vexpress_osc_driver); > > > > -} > > > > -core_initcall(vexpress_osc_init); > > > > +module_platform_driver(vexpress_osc_driver); > > > > > > I am not 100% sure of this. This might break the boot on CA9 and TC2 > > > at-least. There are loads of MB peripherals that need this. This will > > > break the boot. We need to check if all the dependent modules are also > > > at module_initcall level and if they deal with deferred probe correctly. > > > Lot of them are legacy and may happen to be working by carefully initcall > > > level adjustments. > > > > > > > OK I managed to try this on my TC2 and it fails to boot. However when I > > enable earlyprintk as I see no log without it, it boots just fine. > > Well, the uart clocks for TC2 are all dependent on vexpress-osc. The > console setup is going to fail to get the clocks and just fail as > there's no deferred probe for consoles. We need some way to retrigger > the console matching. > Ah right, I didn't bother to look at pl011 as I got it confused with Juno which has on-chip pl011. Sorry I don't know details of how early console hands over to the console. Just wondering how is the dependency resolved when earlyprintk is enabled. The partial log from $ dmesg | grep -i -E "("pl0"|"vexpress"|"console")" below when it boots earlyprintk. I see that console is enabled after vexpress_osc_driver_init is called. --->8 calling vexpress_syscfg_init+0x1/0xe @ 1 initcall vexpress_syscfg_init+0x1/0xe returned 0 after 0 usecs calling vexpress_sysreg_init+0x1/0x48 @ 1 probe of vexpress-syscfg.6.auto returned 1 after 0 usecs initcall vexpress_sysreg_init+0x1/0x48 returned 0 after 0 usecs calling vexpress_config_init+0x1/0xae @ 1 initcall vexpress_config_init+0x1/0xae returned 0 after 0 usecs calling pl011_init+0x1/0x38 @ 1 Serial: AMBA PL011 UART driver initcall pl011_init+0x1/0x38 returned 0 after 9765 usecs calling pl022_init+0x1/0xc @ 1 initcall pl022_init+0x1/0xc returned 0 after 0 usecs calling pl061_gpio_init+0x1/0xc @ 1 initcall pl061_gpio_init+0x1/0xc returned 0 after 31 usecs calling vexpress_osc_driver_init+0x1/0x10 @ 1 initcall vexpress_osc_driver_init+0x1/0x10 returned 0 after 231119 usecs calling vexpress_regulator_driver_init+0x1/0xe @ 1 initcall vexpress_regulator_driver_init+0x1/0xe returned 0 after 114764 usecs calling pl031_driver_init+0x1/0xc @ 1 initcall pl031_driver_init+0x1/0xc returned 0 after 25 usecs calling vexpress_reset_driver_init+0x1/0xe @ 1 initcall vexpress_reset_driver_init+0x1/0xe returned 0 after 594 usecs 1c090000.uart: ttyAMA0 at MMIO 0x1c090000 (irq = 30, base_baud = 0) is a PL011 rev2 printk: console [ttyAMA0] enabled printk: bootconsole [earlycon0] disabled 1c0a0000.uart: ttyAMA1 at MMIO 0x1c0a0000 (irq = 31, base_baud = 0) is a PL011 rev2 1c0b0000.uart: ttyAMA2 at MMIO 0x1c0b0000 (irq = 32, base_baud = 0) is a PL011 rev2 1c0c0000.uart: ttyAMA3 at MMIO 0x1c0c0000 (irq = 33, base_baud = 0) is a PL011 rev2 rtc-pl031 1c170000.rtc: registered as rtc0 rtc-pl031 1c170000.rtc: setting system clock to 2020-04-23T16:54:46 UTC (1587660886) --->8 -- Regards, Sudeep