From: Alexander Sverdlin <alexander.sverdlin@xxxxxxxxxxx> Correct the example in documentation so that disable_irq() is not being called in atomic context and remove the comment allowing to do so "with care" from the function header itself. disable_irq() calls sleeping synchronize_irq(), it's not allowed to call them in atomic context. Link: https://lore.kernel.org/lkml/87k02wbs2n.ffs@tglx/ Signed-off-by: Alexander Sverdlin <alexander.sverdlin@xxxxxxxxxxx> --- Documentation/kernel-hacking/locking.rst | 4 ++-- Documentation/translations/it_IT/kernel-hacking/locking.rst | 4 ++-- kernel/irq/manage.c | 2 -- 3 files changed, 4 insertions(+), 6 deletions(-) diff --git a/Documentation/kernel-hacking/locking.rst b/Documentation/kernel-hacking/locking.rst index 6805ae6e86e65..95fd6e0900d92 100644 --- a/Documentation/kernel-hacking/locking.rst +++ b/Documentation/kernel-hacking/locking.rst @@ -1274,11 +1274,11 @@ Manfred Spraul points out that you can still do this, even if the data is very occasionally accessed in user context or softirqs/tasklets. The irq handler doesn't use a lock, and all other accesses are done as so:: - spin_lock(&lock); + mutex_lock(&lock); disable_irq(irq); ... enable_irq(irq); - spin_unlock(&lock); + mutex_unlock(&lock); The disable_irq() prevents the irq handler from running (and waits for it to finish if it's currently running on other CPUs). diff --git a/Documentation/translations/it_IT/kernel-hacking/locking.rst b/Documentation/translations/it_IT/kernel-hacking/locking.rst index 51af37f2d6210..bfbada56cf351 100644 --- a/Documentation/translations/it_IT/kernel-hacking/locking.rst +++ b/Documentation/translations/it_IT/kernel-hacking/locking.rst @@ -1309,11 +1309,11 @@ se i dati vengono occasionalmente utilizzati da un contesto utente o da un'interruzione software. Il gestore d'interruzione non utilizza alcun *lock*, e tutti gli altri accessi verranno fatti così:: - spin_lock(&lock); + mutex_lock(&lock); disable_irq(irq); ... enable_irq(irq); - spin_unlock(&lock); + mutex_unlock(&lock); La funzione disable_irq() impedisce al gestore d'interruzioni d'essere eseguito (e aspetta che finisca nel caso fosse in esecuzione su diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index 40fe7806cc8c9..2054de5bf3c53 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -722,8 +722,6 @@ EXPORT_SYMBOL(disable_irq_nosync); * This function waits for any pending IRQ handlers for this interrupt * to complete before returning. If you use this function while * holding a resource the IRQ handler may need you will deadlock. - * - * This function may be called - with care - from IRQ context. */ void disable_irq(unsigned int irq) { -- 2.34.1
