[PATCH 3/4] PNP: Allow device to override ACPI device sleep

[Peter Hurley <peter@hurleysoftware.com>]

If the serial console is an ACPI PNP device, the PNP bus attempts to
power-down the device, even though the no_console_suspend command line
parameter is specified (eg., debugging suspend/resume).

Add PNP_SUSPEND capability which is on by default, but when cleared,
prevents pnpacpi_suspend() (which is the ACPI PNP protocol ->suspend()
method).

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
---
 drivers/pnp/driver.c       | 2 +-
 drivers/pnp/pnpacpi/core.c | 2 +-
 include/linux/pnp.h        | 3 +++
 3 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/pnp/driver.c b/drivers/pnp/driver.c
index f748cc8..4e57d33 100644
--- a/drivers/pnp/driver.c
+++ b/drivers/pnp/driver.c
@@ -182,7 +182,7 @@ static int __pnp_bus_suspend(struct device *dev, pm_message_t state)
 			return error;
 	}
 
-	if (pnp_dev->protocol->suspend)
+	if (pnp_can_suspend(pnp_dev))
 		pnp_dev->protocol->suspend(pnp_dev, state);
 	return 0;
 }
diff --git a/drivers/pnp/pnpacpi/core.c b/drivers/pnp/pnpacpi/core.c
index d2b780a..115bb73 100644
--- a/drivers/pnp/pnpacpi/core.c
+++ b/drivers/pnp/pnpacpi/core.c
@@ -253,7 +253,7 @@ static int __init pnpacpi_add_device(struct acpi_device *device)
 	dev->active = device->status.enabled;
 	if (acpi_has_method(device->handle, "_SRS"))
 		dev->capabilities |= PNP_CONFIGURABLE;
-	dev->capabilities |= PNP_READ;
+	dev->capabilities |= PNP_READ | PNP_SUSPEND;
 	if (device->flags.dynamic_status && (dev->capabilities & PNP_CONFIGURABLE))
 		dev->capabilities |= PNP_WRITE;
 	if (device->flags.removable)
diff --git a/include/linux/pnp.h b/include/linux/pnp.h
index 195aafc..5a5cbc2 100644
--- a/include/linux/pnp.h
+++ b/include/linux/pnp.h
@@ -309,6 +309,7 @@ struct pnp_fixup {
 #define PNP_DISABLE		0x0004
 #define PNP_CONFIGURABLE	0x0008
 #define PNP_REMOVABLE		0x0010
+#define PNP_SUSPEND		0x0020
 
 #define pnp_can_read(dev)	(((dev)->protocol->get) && \
 				 ((dev)->capabilities & PNP_READ))
@@ -318,6 +319,8 @@ struct pnp_fixup {
 				 ((dev)->capabilities & PNP_DISABLE))
 #define pnp_can_configure(dev)	((!(dev)->active) && \
 				 ((dev)->capabilities & PNP_CONFIGURABLE))
+#define pnp_can_suspend(dev)	(((dev)->protocol->suspend) && \
+				 ((dev)->capabilities & PNP_SUSPEND))
 
 #ifdef CONFIG_ISAPNP
 extern struct pnp_protocol isapnp_protocol;
-- 
2.1.3