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authorRafael J. Wysocki <rjw@sisk.pl>2009-03-16 17:33:49 -0400
committerRafael J. Wysocki <rjw@sisk.pl>2009-03-30 15:46:54 -0400
commit0a0c5168df270a50e3518e4f12bddb31f8f5f38f (patch)
treeea1e392fef9d52a7b81c9010580c09317a4d707d /kernel/irq/manage.c
parent019abbc87025a030fd25008612afd4eff8a375f7 (diff)
PM: Introduce functions for suspending and resuming device interrupts
Introduce helper functions allowing us to prevent device drivers from getting any interrupts (without disabling interrupts on the CPU) during suspend (or hibernation) and to make them start to receive interrupts again during the subsequent resume. These functions make it possible to keep timer interrupts enabled while the "late" suspend and "early" resume callbacks provided by device drivers are being executed. In turn, this allows device drivers' "late" suspend and "early" resume callbacks to sleep, execute ACPI callbacks etc. The functions introduced here will be used to rework the handling of interrupts during suspend (hibernation) and resume. Namely, interrupts will only be disabled on the CPU right before suspending sysdevs, while device drivers will be prevented from receiving interrupts, with the help of the new helper function, before their "late" suspend callbacks run (and analogously during resume). Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/irq/manage.c')
-rw-r--r--kernel/irq/manage.c31
1 files changed, 24 insertions, 7 deletions
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 6458e99984c..1516ab77355 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -162,6 +162,20 @@ static inline int setup_affinity(unsigned int irq, struct irq_desc *desc)
162} 162}
163#endif 163#endif
164 164
165void __disable_irq(struct irq_desc *desc, unsigned int irq, bool suspend)
166{
167 if (suspend) {
168 if (!desc->action || (desc->action->flags & IRQF_TIMER))
169 return;
170 desc->status |= IRQ_SUSPENDED;
171 }
172
173 if (!desc->depth++) {
174 desc->status |= IRQ_DISABLED;
175 desc->chip->disable(irq);
176 }
177}
178
165/** 179/**
166 * disable_irq_nosync - disable an irq without waiting 180 * disable_irq_nosync - disable an irq without waiting
167 * @irq: Interrupt to disable 181 * @irq: Interrupt to disable
@@ -182,10 +196,7 @@ void disable_irq_nosync(unsigned int irq)
182 return; 196 return;
183 197
184 spin_lock_irqsave(&desc->lock, flags); 198 spin_lock_irqsave(&desc->lock, flags);
185 if (!desc->depth++) { 199 __disable_irq(desc, irq, false);
186 desc->status |= IRQ_DISABLED;
187 desc->chip->disable(irq);
188 }
189 spin_unlock_irqrestore(&desc->lock, flags); 200 spin_unlock_irqrestore(&desc->lock, flags);
190} 201}
191EXPORT_SYMBOL(disable_irq_nosync); 202EXPORT_SYMBOL(disable_irq_nosync);
@@ -215,15 +226,21 @@ void disable_irq(unsigned int irq)
215} 226}
216EXPORT_SYMBOL(disable_irq); 227EXPORT_SYMBOL(disable_irq);
217 228
218static void __enable_irq(struct irq_desc *desc, unsigned int irq) 229void __enable_irq(struct irq_desc *desc, unsigned int irq, bool resume)
219{ 230{
231 if (resume)
232 desc->status &= ~IRQ_SUSPENDED;
233
220 switch (desc->depth) { 234 switch (desc->depth) {
221 case 0: 235 case 0:
236 err_out:
222 WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n", irq); 237 WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n", irq);
223 break; 238 break;
224 case 1: { 239 case 1: {
225 unsigned int status = desc->status & ~IRQ_DISABLED; 240 unsigned int status = desc->status & ~IRQ_DISABLED;
226 241
242 if (desc->status & IRQ_SUSPENDED)
243 goto err_out;
227 /* Prevent probing on this irq: */ 244 /* Prevent probing on this irq: */
228 desc->status = status | IRQ_NOPROBE; 245 desc->status = status | IRQ_NOPROBE;
229 check_irq_resend(desc, irq); 246 check_irq_resend(desc, irq);
@@ -253,7 +270,7 @@ void enable_irq(unsigned int irq)
253 return; 270 return;
254 271
255 spin_lock_irqsave(&desc->lock, flags); 272 spin_lock_irqsave(&desc->lock, flags);
256 __enable_irq(desc, irq); 273 __enable_irq(desc, irq, false);
257 spin_unlock_irqrestore(&desc->lock, flags); 274 spin_unlock_irqrestore(&desc->lock, flags);
258} 275}
259EXPORT_SYMBOL(enable_irq); 276EXPORT_SYMBOL(enable_irq);
@@ -511,7 +528,7 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
511 */ 528 */
512 if (shared && (desc->status & IRQ_SPURIOUS_DISABLED)) { 529 if (shared && (desc->status & IRQ_SPURIOUS_DISABLED)) {
513 desc->status &= ~IRQ_SPURIOUS_DISABLED; 530 desc->status &= ~IRQ_SPURIOUS_DISABLED;
514 __enable_irq(desc, irq); 531 __enable_irq(desc, irq, false);
515 } 532 }
516 533
517 spin_unlock_irqrestore(&desc->lock, flags); 534 spin_unlock_irqrestore(&desc->lock, flags);