From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751842AbaKXJci (ORCPT ); Mon, 24 Nov 2014 04:32:38 -0500 Received: from mga09.intel.com ([134.134.136.24]:46872 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750765AbaKXJcg (ORCPT ); Mon, 24 Nov 2014 04:32:36 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.07,447,1413270000"; d="scan'208";a="642460527" Message-ID: <5472FB31.8000408@intel.com> Date: Mon, 24 Nov 2014 17:32:33 +0800 From: Aaron Lu MIME-Version: 1.0 To: "Rafael J. Wysocki" CC: Lee Jones , Jacob Pan , Yegnesh Iyer , linux-acpi@vger.kernel.org, linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 updated 3/3] ACPI / PMIC: AXP288: support virtual GPIO in ACPI table References: <1416553911-22990-1-git-send-email-aaron.lu@intel.com> <1416553911-22990-4-git-send-email-aaron.lu@intel.com> <1648486.coeVgHKNdn@vostro.rjw.lan> In-Reply-To: <1648486.coeVgHKNdn@vostro.rjw.lan> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/24/2014 09:06 AM, Rafael J. Wysocki wrote: > On Friday, November 21, 2014 03:11:51 PM Aaron Lu wrote: >> + if (!result) { >> + status = acpi_install_address_space_handler( >> + ACPI_HANDLE(parent), ACPI_ADR_SPACE_GPIO, >> + intel_xpower_pmic_gpio_handler, NULL, NULL); > > So here we have a problem, because we can't unregister the opregion handler > registered above if this fails. Not nice. I'm not correct in the cover letter, the actual problem with operation region remove is with module unload, it happens like this: The acpi_remove_address_space_handler doesn't wait for the current running handler to return, so if we call acpi_remove_address_space_handler in a module's exit function, the handler's memory will be freed and the running handler will access to a no longer valid memory place. So as long as we can make sure the handler will not go away from the memory, we are safe. With this said, the updated patch is here: From: Aaron Lu Date: Mon, 20 Oct 2014 17:06:20 +0800 Subject: [PATCH 3/3] ACPI / PMIC: AXP288: support virtual GPIO in ACPI table The same virtual GPIO strategy is also used for the AXP288 PMIC in that various control methods that are used to do power rail handling and sensor reading/setting will touch GPIO fields defined under the PMIC device. The GPIO fileds are only defined by the ACPI code while the actual hardware doesn't really have a GPIO controller, but to make those control method execution succeed, we have to install a GPIO handler for the PMIC device handle. Since we do not need the virtual GPIO strategy, we can simply do nothing in that handler. Signed-off-by: Aaron Lu --- drivers/acpi/pmic/intel_pmic_xpower.c | 30 ++++++++++++++++++++++++++---- 1 file changed, 26 insertions(+), 4 deletions(-) diff --git a/drivers/acpi/pmic/intel_pmic_xpower.c b/drivers/acpi/pmic/intel_pmic_xpower.c index 795ca073db08..9ec57ebd81c9 100644 --- a/drivers/acpi/pmic/intel_pmic_xpower.c +++ b/drivers/acpi/pmic/intel_pmic_xpower.c @@ -220,13 +220,35 @@ static struct intel_pmic_opregion_data intel_xpower_pmic_opregion_data = { .thermal_table_count = ARRAY_SIZE(thermal_table), }; +static acpi_status intel_xpower_pmic_gpio_handler(u32 function, + acpi_physical_address address, u32 bit_width, u64 *value, + void *handler_context, void *region_context) +{ + return AE_OK; +} static int intel_xpower_pmic_opregion_probe(struct platform_device *pdev) { - struct axp20x_dev *axp20x = dev_get_drvdata(pdev->dev.parent); - return intel_pmic_install_opregion_handler(&pdev->dev, - ACPI_HANDLE(pdev->dev.parent), axp20x->regmap, - &intel_xpower_pmic_opregion_data); + struct device *parent = pdev->dev.parent; + struct axp20x_dev *axp20x = dev_get_drvdata(parent); + acpi_status status; + int result; + + status = acpi_install_address_space_handler(ACPI_HANDLE(parent), + ACPI_ADR_SPACE_GPIO, intel_xpower_pmic_gpio_handler, + NULL, NULL); + if (ACPI_FAILURE(status)) + return -ENODEV; + + result = intel_pmic_install_opregion_handler(&pdev->dev, + ACPI_HANDLE(parent), axp20x->regmap, + &intel_xpower_pmic_opregion_data); + if (result) + acpi_remove_address_space_handler(ACPI_HANDLE(parent), + ACPI_ADR_SPACE_GPIO, + intel_xpower_pmic_gpio_handler); + + return result; } static struct platform_driver intel_xpower_pmic_opregion_driver = { -- 1.9.3