From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754357Ab1BBA6y (ORCPT ); Tue, 1 Feb 2011 19:58:54 -0500 Received: from ogre.sisk.pl ([217.79.144.158]:34207 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753420Ab1BBA6v (ORCPT ); Tue, 1 Feb 2011 19:58:51 -0500 From: "Rafael J. Wysocki" To: Len Brown Subject: [PATCH] ACPI: Avoid calling request_irq() many times for the same interrupt Date: Wed, 2 Feb 2011 01:58:15 +0100 User-Agent: KMail/1.13.5 (Linux/2.6.38-rc3+; KDE/4.4.4; x86_64; ; ) Cc: ACPI Devel Maling List , LKML MIME-Version: 1.0 Content-Type: Text/Plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <201102020158.15663.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Rafael J. Wysocki In principle acpi_os_install_interrupt_handler() may be called multiple times for different interrupts, either from acpi_ev_get_gpe_xrupt_block(), or from acpi_ev_install_sci_handler(). However, it always attempts to request the same interrupt, acpi_gbl_FADT.sci_interrupt and it doesn't check whether or not this interrupt has already been requested. Modify this function so that it refuses to request interrupts other than acpi_gbl_FADT.sci_interrupt and change acpi_os_remove_interrupt_handler() so that it refuses to free such interrupts. Use the observation that the only supported ACPI interrupt must be equal to acpi_gbl_FADT.sci_interrupt and drop an unnecessary variable acpi_irq_irq. This change has been tested on Toshiba Portege R500 and HP nx6325 without introducing any visible problems. Signed-off-by: Rafael J. Wysocki --- drivers/acpi/osl.c | 27 +++++++++++++++------------ 1 file changed, 15 insertions(+), 12 deletions(-) Index: linux-2.6/drivers/acpi/osl.c =================================================================== --- linux-2.6.orig/drivers/acpi/osl.c +++ linux-2.6/drivers/acpi/osl.c @@ -76,7 +76,6 @@ EXPORT_SYMBOL(acpi_in_debugger); extern char line_buf[80]; #endif /*ENABLE_DEBUGGER */ -static unsigned int acpi_irq_irq; static acpi_osd_handler acpi_irq_handler; static void *acpi_irq_context; static struct workqueue_struct *kacpid_wq; @@ -532,11 +531,15 @@ acpi_os_install_interrupt_handler(u32 gs acpi_irq_stats_init(); /* - * Ignore the GSI from the core, and use the value in our copy of the - * FADT. It may not be the same if an interrupt source override exists - * for the SCI. + * ACPI interrupts different from the SCI in our copy of the FADT are + * not supported. */ - gsi = acpi_gbl_FADT.sci_interrupt; + if (gsi != acpi_gbl_FADT.sci_interrupt) + return AE_BAD_PARAMETER; + + if (acpi_irq_handler) + return AE_ALREADY_ACQUIRED; + if (acpi_gsi_to_irq(gsi, &irq) < 0) { printk(KERN_ERR PREFIX "SCI (ACPI GSI %d) not registered\n", gsi); @@ -547,20 +550,20 @@ acpi_os_install_interrupt_handler(u32 gs acpi_irq_context = context; if (request_irq(irq, acpi_irq, IRQF_SHARED, "acpi", acpi_irq)) { printk(KERN_ERR PREFIX "SCI (IRQ%d) allocation failed\n", irq); + acpi_irq_handler = NULL; return AE_NOT_ACQUIRED; } - acpi_irq_irq = irq; return AE_OK; } acpi_status acpi_os_remove_interrupt_handler(u32 irq, acpi_osd_handler handler) { - if (irq) { - free_irq(irq, acpi_irq); - acpi_irq_handler = NULL; - acpi_irq_irq = 0; - } + if (irq != acpi_gbl_FADT.sci_interrupt) + return AE_BAD_PARAMETER; + + free_irq(irq, acpi_irq); + acpi_irq_handler = NULL; return AE_OK; } @@ -1619,7 +1622,7 @@ acpi_status __init acpi_os_initialize1(v acpi_status acpi_os_terminate(void) { if (acpi_irq_handler) { - acpi_os_remove_interrupt_handler(acpi_irq_irq, + acpi_os_remove_interrupt_handler(acpi_gbl_FADT.sci_interrupt, acpi_irq_handler); }