[RFC][PATCH -mm 3/3] PM: Disable _request_firmware before hibernation/suspend

Rafael J. Wysocki
2007-05-27T20:31:53Z

From: Rafael J. Wysocki <rjw@sisk.pl>

Use a hibernation and suspend notifier to disable the firmware requesting
mechanism before a hibernation/suspend and enable it after the operation.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

drivers/base/firmware_class.c | 36 ++++++++++++++++++++++++++++++++++++
1 file changed, 36 insertions(+)

Index: linux-2.6.22-rc3/drivers/base/firmware_class.c
===================================================================
--- linux-2.6.22-rc3.orig/drivers/base/firmware_class.c 2007-05-27 19:43:03.000000000 +0200
+++ linux-2.6.22-rc3/drivers/base/firmware_class.c 2007-05-27 19:44:06.000000000 +0200
@@ -17,6 +17,8 @@
#include <linux/bitops.h>
#include <linux/mutex.h>
#include <linux/kthread.h>
+#include <linux/notifier.h>
+#include <linux/suspend.h>

#include <linux/firmware.h>
#include "base.h"
@@ -35,6 +37,9 @@ enum {

static int loading_timeout = 60; /* In seconds */

+/* If set, _request_firmware() will exit immediately returning -EBUSY */
+static int requesting_firmware_disabled;
+
/* fw_lock could be moved to 'struct firmware_priv' but since it is just
* guarding for corner cases a global lock should be OK */
static DEFINE_MUTEX(fw_lock);
@@ -397,6 +402,9 @@ _request_firmware(const struct firmware
struct firmware *firmware;
int retval;

+ if (requesting_firmware_disabled)
+ return -EBUSY;
+
if (!firmware_p)
return -EINVAL;

@@ -568,6 +576,26 @@ request_firmware_nowait(
return 0;
}

+static int firmware_class_pm_callback(struct notifier_block *nfb,
+ unsigned long action,
+ void *ignored)
+{
+ switch (action) {
+ case PM_PRE_FREEZE:
+ requesting_firmware_disabled = 1;
+ return NOTIFY_OK;
+ case PM_POST_THAW:
+ requesting_firmware_disabled = 0;
+ return NOTIFY_OK;
+ }
+
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block firmware_class_pm_nb = {
+ .notifier_call = firmware_class_pm_callback,
+};
+
static int __init
firmware_class_init(void)
{
@@ -582,6 +610,13 @@ firmware_class_init(void)
printk(KERN_ERR "%s: class_create_file failed\n",
__FUNCTION__);
class_unregister(&firmware_class);
+ return error;
+ }
+ error = register_pm_notifier(&firmware_class_pm_nb);
+ if (error) {
+ printk(KERN_ERR "%s: register_pm_notifier failed\n",
+ __FUNCTION__);
+ class_unregister(&firmware_class);
}
return error;

@@ -589,6 +624,7 @@ firmware_class_init(void)
static void __exit
firmware_class_exit(void)
{
+ unregister_pm_notifier(&firmware_class_pm_nb);
class_unregister(&firmware_class);
}