Commit 23fe3630 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki
Browse files

ACPI: Avoid calling request_irq() many times for the same interrupt 



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: default avatarRafael J. Wysocki <rjw@sisk.pl>
parent 2aa15890

drivers/acpi/osl.c

+15 −12
Original line number Diff line number Diff line
@@ -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;
@@ -516,11 +515,15 @@ acpi_os_install_interrupt_handler(u32 gsi, acpi_osd_handler handler, 
	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);
@@ -531,20 +534,20 @@ acpi_os_install_interrupt_handler(u32 gsi, acpi_osd_handler handler, 
	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) {

	if (irq != acpi_gbl_FADT.sci_interrupt)

		return AE_BAD_PARAMETER;



	free_irq(irq, acpi_irq);

	acpi_irq_handler = NULL;

		acpi_irq_irq = 0;

	}



	return AE_OK;

}
@@ -1603,7 +1606,7 @@ acpi_status __init acpi_os_initialize1(void) 
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);

	}

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