This is a note to let you know that I've just added the patch titled
PM: Print a warning if firmware is requested when tasks are frozen
to the 2.6.32-longterm tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/longterm/longterm-queue-2.6.32.git;a=summary
The filename of the patch is:
pm-print-a-warning-if-firmware-is-requested-when-tasks.patch
and it can be found in the queue-2.6.32 subdirectory.
If you, or anyone else, feels it should not be added to the 2.6.32 longterm
tree,
please let <[email protected]> know about it.
>From [email protected] Thu Mar 1 13:30:46 2012
From: "Srivatsa S. Bhat" <[email protected]>
Date: Wed, 29 Feb 2012 12:22:41 +0530
Subject: PM: Print a warning if firmware is requested when tasks are frozen
To: [email protected]
Cc: [email protected], [email protected], [email protected],
[email protected], [email protected], [email protected],
[email protected], [email protected]
Message-ID: <[email protected]>
From: Rafael J. Wysocki <[email protected]>
[ Upstream commit a144c6a6c924aa1da04dd77fb84b89927354fdff ]
Some drivers erroneously use request_firmware() from their ->resume()
(or ->thaw(), or ->restore()) callbacks, which is not going to work
unless the firmware has been built in. This causes system resume to
stall until the firmware-loading timeout expires, which makes users
think that the resume has failed and reboot their machines
unnecessarily. For this reason, make _request_firmware() print a
warning and return immediately with error code if it has been called
when tasks are frozen and it's impossible to start any new usermode
helpers.
Signed-off-by: Rafael J. Wysocki <[email protected]>
Acked-by: Greg Kroah-Hartman <[email protected]>
Reviewed-by: Valdis Kletnieks <[email protected]>
Signed-off-by: Srivatsa S. Bhat <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/base/firmware_class.c | 5 +++++
include/linux/kmod.h | 5 +++++
kernel/kmod.c | 9 +++++++++
3 files changed, 19 insertions(+)
--- a/drivers/base/firmware_class.c
+++ b/drivers/base/firmware_class.c
@@ -489,6 +489,11 @@ _request_firmware(const struct firmware
if (!firmware_p)
return -EINVAL;
+ if (WARN_ON(usermodehelper_is_disabled())) {
+ dev_err(device, "firmware: %s will not be loaded\n", name);
+ return -EBUSY;
+ }
+
*firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
if (!firmware) {
dev_err(device, "%s: kmalloc(struct firmware) failed\n",
--- a/include/linux/kmod.h
+++ b/include/linux/kmod.h
@@ -104,7 +104,12 @@ struct file;
extern int call_usermodehelper_pipe(char *path, char *argv[], char *envp[],
struct file **filp);
+#ifdef CONFIG_PM_SLEEP
extern int usermodehelper_disable(void);
extern void usermodehelper_enable(void);
+extern bool usermodehelper_is_disabled(void);
+#else
+static inline bool usermodehelper_is_disabled(void) { return false; }
+#endif
#endif /* __LINUX_KMOD_H__ */
--- a/kernel/kmod.c
+++ b/kernel/kmod.c
@@ -337,6 +337,15 @@ void usermodehelper_enable(void)
usermodehelper_disabled = 0;
}
+/**
+ * usermodehelper_is_disabled - check if new helpers are allowed to be started
+ */
+bool usermodehelper_is_disabled(void)
+{
+ return usermodehelper_disabled;
+}
+EXPORT_SYMBOL_GPL(usermodehelper_is_disabled);
+
static void helper_lock(void)
{
atomic_inc(&running_helpers);
Patches currently in longterm-queue-2.6.32 which might be from
[email protected] are
/home/gregkh/linux/longterm/longterm-queue-2.6.32/queue-2.6.32/pm-sleep-fix-read_unlock_usermodehelper-call.patch
/home/gregkh/linux/longterm/longterm-queue-2.6.32/queue-2.6.32/firmware-loader-allow-builtin-firmware-load-even-if-usermodehelper-is-disabled.patch
/home/gregkh/linux/longterm/longterm-queue-2.6.32/queue-2.6.32/pm-print-a-warning-if-firmware-is-requested-when-tasks.patch
/home/gregkh/linux/longterm/longterm-queue-2.6.32/queue-2.6.32/pm-sleep-fix-freezer-failures-due-to-racy-usermodehelper_is_disabled.patch
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