linux-kernel - [tip: irq/core] docs: locking: Discourage from calling disable

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Date:   Wed, 11 Jan 2023 21:17:37 -0000
From:   "tip-bot2 for Alexander Sverdlin" <tip-bot2@...utronix.de>
To:     linux-tip-commits@...r.kernel.org
Cc:     Alexander Sverdlin <alexander.sverdlin@...mens.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Manfred Spraul <manfred@...orfullife.com>,
        linux-doc@...r.kernel.org, x86@...nel.org,
        linux-kernel@...r.kernel.org, maz@...nel.org
Subject: [tip: irq/core] docs: locking: Discourage from calling disable_irq()
 in atomic

The following commit has been merged into the irq/core branch of tip:

Commit-ID:     379af13b31fa8a36ad4abd59a5c511f25c5d4d42
Gitweb:        https://git.kernel.org/tip/379af13b31fa8a36ad4abd59a5c511f25c5d4d42
Author:        Alexander Sverdlin <alexander.sverdlin@...mens.com>
AuthorDate:    Mon, 12 Dec 2022 17:37:15 +01:00
Committer:     Thomas Gleixner <tglx@...utronix.de>
CommitterDate: Wed, 11 Jan 2023 19:45:26 +01:00

docs: locking: Discourage from calling disable_irq() in atomic

Correct the example in the documentation so that disable_irq() is not being
called in atomic context.

disable_irq() calls sleeping synchronize_irq(), it's not allowed to call
them in atomic context.

Signed-off-by: Alexander Sverdlin <alexander.sverdlin@...mens.com>
Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
Reviewed-by: Manfred Spraul <manfred@...orfullife.com>
Cc: linux-doc@...r.kernel.org
Link: https://lore.kernel.org/lkml/87k02wbs2n.ffs@tglx/
Link: https://lore.kernel.org/r/20221212163715.830315-1-alexander.sverdlin@siemens.com

---
 Documentation/kernel-hacking/locking.rst                    | 4 ++--
 Documentation/translations/it_IT/kernel-hacking/locking.rst | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/Documentation/kernel-hacking/locking.rst b/Documentation/kernel-hacking/locking.rst
index c756786..dff0646 100644
--- a/Documentation/kernel-hacking/locking.rst
+++ b/Documentation/kernel-hacking/locking.rst
@@ -1277,11 +1277,11 @@ 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 b8ecf41..05d362b 100644
--- a/Documentation/translations/it_IT/kernel-hacking/locking.rst
+++ b/Documentation/translations/it_IT/kernel-hacking/locking.rst
@@ -1307,11 +1307,11 @@ 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