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| author |   Rafael J. Wysocki <rjw@sisk.pl> | 2011-05-06 20:09:42 +0200 |
|---|---|---|
| committer | Rafael J. Wysocki <rjw@sisk.pl> | 2011-05-17 23:19:17 +0200 |
| commit | a144c6a6c924aa1da04dd77fb84b89927354fdff (patch) | |
| tree | 10cab9080a722a191086f58b9f304329e8a8b942 | |
| parent | PM / Runtime: Rework runtime PM handling during driver removal (diff) | |
| download | linux-dev-a144c6a6c924aa1da04dd77fb84b89927354fdff.tar.xz linux-dev-a144c6a6c924aa1da04dd77fb84b89927354fdff.zip | |
PM: Print a warning if firmware is requested when tasks are frozen
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 <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Reviewed-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
| -rw-r--r-- | drivers/base/firmware_class.c | 5 | ||||
| -rw-r--r-- | include/linux/kmod.h | 5 | ||||
| -rw-r--r-- | kernel/kmod.c | 9 |
3 files changed, 19 insertions, 0 deletions
diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c index 8c798ef7f13f..bbb03e6f7255 100644 --- a/drivers/base/firmware_class.c +++ b/drivers/base/firmware_class.c @@ -521,6 +521,11 @@ static int _request_firmware(const struct firmware **firmware_p, 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", diff --git a/include/linux/kmod.h b/include/linux/kmod.h index 6efd7a78de6a..7f3dbcb78116 100644 --- a/include/linux/kmod.h +++ b/include/linux/kmod.h @@ -111,7 +111,12 @@ call_usermodehelper(char *path, char **argv, char **envp, enum umh_wait wait) extern void usermodehelper_init(void); +#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__ */ diff --git a/kernel/kmod.c b/kernel/kmod.c index 9cd0591c96a2..9ab513bd0c3c 100644 --- a/kernel/kmod.c +++ b/kernel/kmod.c @@ -301,6 +301,15 @@ 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); |