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

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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 <rjw@sisk.pl>
This commit is contained in:
Rafael J. Wysocki 2011-02-08 23:48:16 +01:00
parent 2aa15890f3
commit 23fe36306e
1 changed files with 15 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

27
drivers/acpi/osl.c
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@ -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) {
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;
}
@ -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);
}