pnpacpi: fix IRQ flag decoding

When decoding IRQ trigger mode and polarity, it is not enough to mask by
IORESOURCE_BITS because there are now additional bits defined.  For
example, if IORESOURCE_IRQ_SHAREABLE was set, we failed to set *triggering
and *polarity at all.

I can't point to a failure that this patch fixes, but
bugs in this area have caused problems when resuming after
suspend, for example:

    http://bugzilla.kernel.org/show_bug.cgi?id=6316
    http://bugzilla.kernel.org/show_bug.cgi?id=9487
    https://bugs.launchpad.net/ubuntu/+source/linux-source-2.6.22/+bug/152187

This is based on a patch by Tom Jaeger:
    http://bugzilla.kernel.org/show_bug.cgi?id=9487#c32

[rene.herman@keyaccess.nl: fix comment]
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 12 insertions, 4 deletions

diff --git a/drivers/pnp/pnpacpi/rsparser.c b/drivers/pnp/pnpacpi/rsparser.c
index 0201c8adfda7..ab09fe6fe1e4 100644
--- a/drivers/pnp/pnpacpi/rsparser.c
+++ b/drivers/pnp/pnpacpi/rsparser.c
@@ -56,9 +56,11 @@ static int irq_flags(int triggering, int polarity, int shareable)
         return flags;
 }
 
-static void decode_irq_flags(int flag, int *triggering, int *polarity)
+static void decode_irq_flags(struct pnp_dev *dev, int flags, int *triggering,
+                             int *polarity)
 {
-        switch (flag) {
+        switch (flags & (IORESOURCE_IRQ_LOWLEVEL | IORESOURCE_IRQ_HIGHLEVEL |
+                         IORESOURCE_IRQ_LOWEDGE  | IORESOURCE_IRQ_HIGHEDGE)) {
         case IORESOURCE_IRQ_LOWLEVEL:
                 *triggering = ACPI_LEVEL_SENSITIVE;
                 *polarity = ACPI_ACTIVE_LOW;
@@ -75,6 +77,12 @@ static void decode_irq_flags(int flag, int *triggering, int *polarity)
                 *triggering = ACPI_EDGE_SENSITIVE;
                 *polarity = ACPI_ACTIVE_HIGH;
                 break;
+        default:
+                dev_err(&dev->dev, "can't encode invalid IRQ mode %#x\n",
+                        flags);
+                *triggering = ACPI_EDGE_SENSITIVE;
+                *polarity = ACPI_ACTIVE_HIGH;
+                break;
         }
 }
 
@@ -790,7 +798,7 @@ static void pnpacpi_encode_irq(struct pnp_dev *dev,
         struct acpi_resource_irq *irq = &resource->data.irq;
         int triggering, polarity;
 
-        decode_irq_flags(p->flags & IORESOURCE_BITS, &triggering, &polarity);
+        decode_irq_flags(dev, p->flags, &triggering, &polarity);
         irq->triggering = triggering;
         irq->polarity = polarity;
         if (triggering == ACPI_EDGE_SENSITIVE)
@@ -813,7 +821,7 @@ static void pnpacpi_encode_ext_irq(struct pnp_dev *dev,
         struct acpi_resource_extended_irq *extended_irq = &resource->data.extended_irq;
         int triggering, polarity;
 
-        decode_irq_flags(p->flags & IORESOURCE_BITS, &triggering, &polarity);
+        decode_irq_flags(dev, p->flags, &triggering, &polarity);
         extended_irq->producer_consumer = ACPI_CONSUMER;
         extended_irq->triggering = triggering;
         extended_irq->polarity = polarity;