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Commit a144c6a6c924aa1da04dd77fb84b89927354fdff

Authored by Rafael J. Wysocki
1 parent e1866b33b1
Exists in master and in 7 other branches imx_3.0.35_4.1.0, imx_3.10.17_1.0.1_ga, imx_3.10.53_1.1.0_ga, imx_3.14.28_1.0.0_ga, smarc-imx_3.10.53_1.1.0_ga, smarc-imx_3.14.28_1.0.0_ga, smarc-l5.0.0_1.0.0-ga

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>

Showing 3 changed files with 19 additions and 0 deletions Side-by-side Diff

drivers/base/firmware_class.c
Diff comments   View file @ a144c6a
... ... @@ -521,6 +521,11 @@
521 521 if (!firmware_p)
522 522 return -EINVAL;
523 523  
  524 + if (WARN_ON(usermodehelper_is_disabled())) {
  525 + dev_err(device, "firmware: %s will not be loaded\n", name);
  526 + return -EBUSY;
  527 + }
  528 +
524 529 *firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
525 530 if (!firmware) {
526 531 dev_err(device, "%s: kmalloc(struct firmware) failed\n",
include/linux/kmod.h
Diff comments   View file @ a144c6a
... ... @@ -111,8 +111,13 @@
111 111  
112 112 extern void usermodehelper_init(void);
113 113  
  114 +#ifdef CONFIG_PM_SLEEP
114 115 extern int usermodehelper_disable(void);
115 116 extern void usermodehelper_enable(void);
  117 +extern bool usermodehelper_is_disabled(void);
  118 +#else
  119 +static inline bool usermodehelper_is_disabled(void) { return false; }
  120 +#endif
116 121  
117 122 #endif /* __LINUX_KMOD_H__ */
... ... @@ -301,6 +301,15 @@
301 301 usermodehelper_disabled = 0;
302 302 }
303 303  
  304 +/**
  305 + * usermodehelper_is_disabled - check if new helpers are allowed to be started
  306 + */
  307 +bool usermodehelper_is_disabled(void)
  308 +{
  309 + return usermodehelper_disabled;
  310 +}
  311 +EXPORT_SYMBOL_GPL(usermodehelper_is_disabled);
  312 +
304 313 static void helper_lock(void)
305 314 {
306 315 atomic_inc(&running_helpers);