pcmcia: irq probe can be done without risking an IRQ storm

Nowdays you can ask for an IRQ to be allocated but not enabled, when PCMCIA
was written this was not true and this feature is thus not used

[linux@dominikbrodowski.net: add comment and ifdef to avoid compilation
 breakage at least on alpha]
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>

1 files changed, 9 insertions, 0 deletions

diff --git a/drivers/pcmcia/pcmcia_resource.c b/drivers/pcmcia/pcmcia_resource.c
index c8f77b889d42..78af59415930 100644
--- a/drivers/pcmcia/pcmcia_resource.c
+++ b/drivers/pcmcia/pcmcia_resource.c
@@ -812,6 +812,15 @@ int pcmcia_request_irq(struct pcmcia_device *p_dev, irq_req_t *req)
                 type = IRQF_SHARED;
 
 #ifdef CONFIG_PCMCIA_PROBE
+
+#ifdef IRQ_NOAUTOEN
+        /* if the underlying IRQ infrastructure allows for it, only allocate
+         * the IRQ, but do not enable it
+         */
+        if (!(req->Attributes & IRQ_HANDLE_PRESENT))
+                type |= IRQ_NOAUTOEN;
+#endif /* IRQ_NOAUTOEN */
+
         if (s->irq.AssignedIRQ != 0) {
                 /* If the interrupt is already assigned, it must be the same */
                 irq = s->irq.AssignedIRQ;