From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthias Brugger Subject: Re: [PATCH v2 1/8] arm64: move acpi/dt decision earlier in boot process Date: Wed, 24 Feb 2016 19:22:12 +0100 Message-ID: <56CDF4D4.6000506@suse.com> References: <1456333819-13482-1-git-send-email-aleksey.makarov@linaro.org> <1456333819-13482-2-git-send-email-aleksey.makarov@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from smtp.nue.novell.com ([195.135.221.5]:53772 "EHLO smtp.nue.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754701AbcBXSWk (ORCPT ); Wed, 24 Feb 2016 13:22:40 -0500 In-Reply-To: <1456333819-13482-2-git-send-email-aleksey.makarov@linaro.org> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Aleksey Makarov , linux-acpi@vger.kernel.org Cc: Russell King , Graeme Gregory , Greg Kroah-Hartman , "Rafael J . Wysocki" , linux-kernel@vger.kernel.org, Leif Lindholm , Christopher Covington , linux-serial@vger.kernel.org, Catalin Marinas , Will Deacon , Al Stone , linux-arm-kernel@lists.infradead.org On 24/02/16 18:10, Aleksey Makarov wrote: > From: Leif Lindholm > > In order to support selecting earlycon via either ACPI or DT, move > the decision on whether to attempt ACPI configuration into the > early_param handling. Then make acpi_boot_table_init() bail out if > acpi_disabled. > > Signed-off-by: Leif Lindholm > Signed-off-by: Aleksey Makarov > --- > arch/arm64/kernel/acpi.c | 62 +++++++++++++++++++++++------------------------- > 1 file changed, 30 insertions(+), 32 deletions(-) > > diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c > index d1ce8e2..3faa323 100644 > --- a/arch/arm64/kernel/acpi.c > +++ b/arch/arm64/kernel/acpi.c > @@ -41,26 +41,8 @@ EXPORT_SYMBOL(acpi_disabled); > int acpi_pci_disabled = 1; /* skip ACPI PCI scan and IRQ initialization */ > EXPORT_SYMBOL(acpi_pci_disabled); > > -static bool param_acpi_off __initdata; > static bool param_acpi_force __initdata; > > -static int __init parse_acpi(char *arg) > -{ > - if (!arg) > - return -EINVAL; > - > - /* "acpi=off" disables both ACPI table parsing and interpreter */ > - if (strcmp(arg, "off") == 0) > - param_acpi_off = true; > - else if (strcmp(arg, "force") == 0) /* force ACPI to be enabled */ > - param_acpi_force = true; > - else > - return -EINVAL; /* Core will print when we return error */ > - > - return 0; > -} > -early_param("acpi", parse_acpi); > - > static int __init dt_scan_depth1_nodes(unsigned long node, > const char *uname, int depth, > void *data) > @@ -74,6 +56,35 @@ static int __init dt_scan_depth1_nodes(unsigned long node, > return 0; > } > > +static int __init parse_acpi(char *arg) > +{ > + if (!arg) > + return -EINVAL; > + > + /* > + * Enable ACPI instead of device tree unless > + * - ACPI has been disabled explicitly (acpi=off), or > + * - the device tree is not empty (it has more than just a /chosen node) > + * and ACPI has not been force enabled (acpi=force) > + */ > + if (strcmp(arg, "off") == 0) > + return 0; > + else if (strcmp(arg, "force") == 0) > + param_acpi_force = true; > + else if (of_scan_flat_dt(dt_scan_depth1_nodes, NULL)) I think we should strcmp for "on" here and return an error on other values. IMHO an update to Documentation/kernel-parameters.txt would be convenient. I still wonder if we really want to change the default to ACPI disabled. But that's a decision the maintainers have to take. Regards, Matthias > + return 0; > + > + /* > + * ACPI is disabled at this point. Enable it in order to parse > + * the ACPI tables and carry out sanity checks > + */ > + enable_acpi(); > + > + return 0; > +} > + > +early_param("acpi", parse_acpi); > + > /* > * __acpi_map_table() will be called before page_init(), so early_ioremap() > * or early_memremap() should be called here to for ACPI table mapping. > @@ -181,23 +192,10 @@ out: > */ > void __init acpi_boot_table_init(void) > { > - /* > - * Enable ACPI instead of device tree unless > - * - ACPI has been disabled explicitly (acpi=off), or > - * - the device tree is not empty (it has more than just a /chosen node) > - * and ACPI has not been force enabled (acpi=force) > - */ > - if (param_acpi_off || > - (!param_acpi_force && of_scan_flat_dt(dt_scan_depth1_nodes, NULL))) > + if (acpi_disabled) > return; > > /* > - * ACPI is disabled at this point. Enable it in order to parse > - * the ACPI tables and carry out sanity checks > - */ > - enable_acpi(); > - > - /* > * If ACPI tables are initialized and FADT sanity checks passed, > * leave ACPI enabled and carry on booting; otherwise disable ACPI > * on initialization error. >