[PATCH] ACPI: GED: add support for _Exx / _Lxx handler methods

From: Ard Biesheuvel
Date: Fri May 15 2020 - 05:37:20 EST


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: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx>
Cc: Len Brown <lenb@xxxxxxxxxx>
Cc: linux-acpi@xxxxxxxxxxxxxxx
Cc: <stable@xxxxxxxxxxxxxxx> # v4.9+
Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
---
drivers/acpi/evged.c | 22 +++++++++++++++++---
1 file changed, 19 insertions(+), 3 deletions(-)

diff --git a/drivers/acpi/evged.c b/drivers/acpi/evged.c
index aba0d0027586..6d7a522952bf 100644
--- 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;
}
--
2.17.1