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authorDavid Brownell <david-b@pacbell.net>2006-07-30 06:03:08 -0400
committerLinus Torvalds <torvalds@g5.osdl.org>2006-07-31 16:28:36 -0400
commit15a647eba94c3da27ccc666bea72e7cca06b2d19 (patch)
treeb4fbc1e78cb298a36d1106847be1433553d217c8 /kernel
parent5e44ef238b7eb607532e89249e7b2523faf77a92 (diff)
[PATCH] genirq: {en,dis}able_irq_wake() need refcounting too
IRQs need refcounting and a state flag to track whether the the IRQ should be enabled or disabled as a "normal IRQ" source after a series of calls to {en,dis}able_irq(). For shared IRQs, the IRQ must be enabled so long as at least one driver needs it active. Likewise, IRQs need the same support to track whether the IRQ should be enabled or disabled as a "wakeup event" source after a series of calls to {en,dis}able_irq_wake(). For shared IRQs, the IRQ must be enabled as a wakeup source during sleep so long as at least one driver needs it. But right now they _don't have_ that refcounting ... which means sharing a wakeup-capable IRQ can't work correctly in some configurations. This patch adds the refcount and flag mechanisms to set_irq_wake() -- which is what {en,dis}able_irq_wake() call -- and minimal documentation of what the irq wake mechanism does. Drivers relying on the older (broken) "toggle" semantics will trigger a warning; that'll be a handful of drivers on ARM systems. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Acked-by: Ingo Molnar <mingo@elte.hu> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/irq/manage.c28
1 files changed, 26 insertions, 2 deletions
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 4e461438e48b..92be519eff26 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -137,16 +137,40 @@ EXPORT_SYMBOL(enable_irq);
137 * @irq: interrupt to control 137 * @irq: interrupt to control
138 * @on: enable/disable power management wakeup 138 * @on: enable/disable power management wakeup
139 * 139 *
140 * Enable/disable power management wakeup mode 140 * Enable/disable power management wakeup mode, which is
141 * disabled by default. Enables and disables must match,
142 * just as they match for non-wakeup mode support.
143 *
144 * Wakeup mode lets this IRQ wake the system from sleep
145 * states like "suspend to RAM".
141 */ 146 */
142int set_irq_wake(unsigned int irq, unsigned int on) 147int set_irq_wake(unsigned int irq, unsigned int on)
143{ 148{
144 struct irq_desc *desc = irq_desc + irq; 149 struct irq_desc *desc = irq_desc + irq;
145 unsigned long flags; 150 unsigned long flags;
146 int ret = -ENXIO; 151 int ret = -ENXIO;
152 int (*set_wake)(unsigned, unsigned) = desc->chip->set_wake;
147 153
154 /* wakeup-capable irqs can be shared between drivers that
155 * don't need to have the same sleep mode behaviors.
156 */
148 spin_lock_irqsave(&desc->lock, flags); 157 spin_lock_irqsave(&desc->lock, flags);
149 if (desc->chip->set_wake) 158 if (on) {
159 if (desc->wake_depth++ == 0)
160 desc->status |= IRQ_WAKEUP;
161 else
162 set_wake = NULL;
163 } else {
164 if (desc->wake_depth == 0) {
165 printk(KERN_WARNING "Unbalanced IRQ %d "
166 "wake disable\n", irq);
167 WARN_ON(1);
168 } else if (--desc->wake_depth == 0)
169 desc->status &= ~IRQ_WAKEUP;
170 else
171 set_wake = NULL;
172 }
173 if (set_wake)
150 ret = desc->chip->set_wake(irq, on); 174 ret = desc->chip->set_wake(irq, on);
151 spin_unlock_irqrestore(&desc->lock, flags); 175 spin_unlock_irqrestore(&desc->lock, flags);
152 return ret; 176 return ret;