RE: [PATCH 3/3] ACPI / scan: Enable GPEs before scanning the namespace

From	"Zheng, Lv" <lv.zheng@intel.com>
Newsgroups	linux.kernel
Subject	RE: [PATCH 3/3] ACPI / scan: Enable GPEs before scanning the namespace
Date	2017-08-15 04:20 +0200
Message-ID	<uezCx-3JS-1@gated-at.bofh.it> (permalink)
References	<ucHXz-5dd-7@gated-at.bofh.it> <ucHXA-5dd-15@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

Hi, Rafael

> From: linux-acpi-owner@vger.kernel.org [mailto:linux-acpi-owner@vger.kernel.org] On Behalf Of Rafael J.
> Wysocki
> Subject: [PATCH 3/3] ACPI / scan: Enable GPEs before scanning the namespace
> 
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> 
> On some systems the platform firmware expects GPEs to be enabled
> before the enumeration of devices and if that expectation is not
> met, the systems in question may not boot in some situations.
> 
> For this reason, change the initialization ordering of the ACPI
> subsystem to make it enable GPEs before scanning the namespace
> for the first time in order to enumerate devices.
> 
> Reported-by: Mika Westerberg <mika.westerberg@linux.intel.com>
> Suggested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> ---
>  drivers/acpi/scan.c |    8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> Index: linux-pm/drivers/acpi/scan.c
> ===================================================================
> --- linux-pm.orig/drivers/acpi/scan.c
> +++ linux-pm/drivers/acpi/scan.c
> @@ -2139,6 +2139,10 @@ int __init acpi_scan_init(void)
>  			acpi_get_spcr_uart_addr();
>  	}
> 
> +	acpi_gpe_apply_masked_gpes();
> +	acpi_update_all_gpes();
> +	acpi_ec_ecdt_start();
> +

Just for your information.
A recent internal bug reveals that acpi_ec_ecdt_start() should only be
invoked after the enumeration (acpi_ec_add()) for now.
The function contains logics that need to be altered by acpi_ec_add().

So it seems we can only do less aggressive change by moving the GPE
related 2 lines up.

Thanks and best regards
Lv

>  	mutex_lock(&acpi_scan_lock);
>  	/*
>  	 * Enumerate devices in the ACPI namespace.
> @@ -2163,10 +2167,6 @@ int __init acpi_scan_init(void)
>  		}
>  	}
> 
> -	acpi_gpe_apply_masked_gpes();
> -	acpi_update_all_gpes();
> -	acpi_ec_ecdt_start();
> -
>  	acpi_scan_initialized = true;
> 
>   out:
> 
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Back to linux.kernel | Previous | Next — Next in thread | Find similar | Unroll thread

Thread

RE: [PATCH 3/3] ACPI / scan: Enable GPEs before scanning the  namespace "Zheng, Lv" <lv.zheng@intel.com> - 2017-08-15 04:20 +0200
  Re: [PATCH 3/3] ACPI / scan: Enable GPEs before scanning the namespace "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2017-08-15 14:40 +0200
    RE: [PATCH 3/3] ACPI / scan: Enable GPEs before scanning the  namespace "Zheng, Lv" <lv.zheng@intel.com> - 2017-08-17 04:30 +0200

csiph-web