PNP: Allow console to override ACPI device sleep

If the serial console is an ACPI PNP device, the PNP bus always powers
down the device at system suspend, even though the no_console_suspend
command line parameter is specified (eg., when debugging suspend/resume).

Add PNP_CONSOLE capability, which when set, prevents calling both the
->disable() and ->suspend() PNP protocol methods if console suspend
is disabled.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2 files changed, 11 insertions, 3 deletions

diff --git a/drivers/pnp/driver.c b/drivers/pnp/driver.c
index f748cc8cbb03..4e57d3370368 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/include/linux/pnp.h b/include/linux/pnp.h
index 195aafc6cd07..6512e9cbc6d5 100644
--- a/include/linux/pnp.h
+++ b/include/linux/pnp.h
@@ -12,6 +12,7 @@
 #include <linux/list.h>
 #include <linux/errno.h>
 #include <linux/mod_devicetable.h>
+#include <linux/console.h>
 
 #define PNP_NAME_LEN            50
 
@@ -309,15 +310,22 @@ struct pnp_fixup {
 #define PNP_DISABLE             0x0004
 #define PNP_CONFIGURABLE        0x0008
 #define PNP_REMOVABLE           0x0010
+#define PNP_CONSOLE             0x0020
 
 #define pnp_can_read(dev)       (((dev)->protocol->get) && \
                                  ((dev)->capabilities & PNP_READ))
 #define pnp_can_write(dev)      (((dev)->protocol->set) && \
                                  ((dev)->capabilities & PNP_WRITE))
-#define pnp_can_disable(dev)    (((dev)->protocol->disable) && \
-                                 ((dev)->capabilities & PNP_DISABLE))
+#define pnp_can_disable(dev)    (((dev)->protocol->disable) &&            \
+                                 ((dev)->capabilities & PNP_DISABLE) &&   \
+                                 (!((dev)->capabilities & PNP_CONSOLE) || \
+                                  console_suspend_enabled))
 #define pnp_can_configure(dev)  ((!(dev)->active) && \
                                  ((dev)->capabilities & PNP_CONFIGURABLE))
+#define pnp_can_suspend(dev)    (((dev)->protocol->suspend) &&            \
+                                 (!((dev)->capabilities & PNP_CONSOLE) || \
+                                  console_suspend_enabled))
+
 
 #ifdef CONFIG_ISAPNP
 extern struct pnp_protocol isapnp_protocol;