ACPI: GED: add support for _Exx / _Lxx handler methods

Per the ACPI spec, interrupts in the range [0, 255] may be handled
in AML using individual methods whose naming is based on the format
_Exx or _Lxx, where xx is the hex representation of the interrupt
index.

Add support for this missing feature to our ACPI GED driver.

Cc: v4.9+ <stable@vger.kernel.org> # v4.9+
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/acpi/evged.c b/drivers/acpi/evged.c
index aba0d00..6d7a522 100644 (file)
--- a/drivers/acpi/evged.c
+++ b/drivers/acpi/evged.c
@@ -79,6 +79,8 @@ static acpi_status acpi_ged_request_interrupt(struct acpi_resource *ares,
        struct resource r;
        struct acpi_resource_irq *p = &ares->data.irq;
        struct acpi_resource_extended_irq *pext = &ares->data.extended_irq;
+       char ev_name[5];
+       u8 trigger;
 
        if (ares->type == ACPI_RESOURCE_TYPE_END_TAG)
                return AE_OK;
@@ -87,14 +89,28 @@ static acpi_status acpi_ged_request_interrupt(struct acpi_resource *ares,
                dev_err(dev, "unable to parse IRQ resource\n");
                return AE_ERROR;
        }
-       if (ares->type == ACPI_RESOURCE_TYPE_IRQ)
+       if (ares->type == ACPI_RESOURCE_TYPE_IRQ) {
                gsi = p->interrupts[0];
-       else
+               trigger = p->triggering;
+       } else {
                gsi = pext->interrupts[0];
+               trigger = p->triggering;
+       }
 
        irq = r.start;
 
-       if (ACPI_FAILURE(acpi_get_handle(handle, "_EVT", &evt_handle))) {
+       switch (gsi) {
+       case 0 ... 255:
+               sprintf(ev_name, "_%c%02hhX",
+                       trigger == ACPI_EDGE_SENSITIVE ? 'E' : 'L', gsi);
+
+               if (ACPI_SUCCESS(acpi_get_handle(handle, ev_name, &evt_handle)))
+                       break;
+               /* fall through */
+       default:
+               if (ACPI_SUCCESS(acpi_get_handle(handle, "_EVT", &evt_handle)))
+                       break;
+
                dev_err(dev, "cannot locate _EVT method\n");
                return AE_ERROR;
        }