From ce5b0773ec68a523f386f9bdd40014c880a92d43 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ma=C3=ADra=20Canal?= Date: Tue, 11 Aug 2026 16:36:11 -0300 Subject: [PATCH] gpiolib: Don't bypass SRCU when CONFIG_LOCKDEP is enabled MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Commit 6c967417fe83 ("gpiolib: Avoid the hotplug performance reduction") stubs out gpiolib's SRCU read-side locking to recover the throughput lost to the hotplug interlock. That trade-off is deliberate, but it leaves the core's lockdep_assert_held(&gc->gpiodev->srcu) checks in place while the lock is never actually taken. Since those are WARN_ON(), every GPIO access splats with CONFIG_LOCKDEP=y and the log fills up with backtraces. Therefore, only enable REJECT_HOTPLUG_TAX when CONFIG_LOCKDEP is disabled. This way, the optimisation is kept for production builds, but developers can still debug the kernel with lockdep enabled. Fixes: 6c967417fe83 ("gpiolib: Avoid the hotplug performance reduction") Signed-off-by: Maíra Canal --- drivers/gpio/gpiolib.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index e4ed169e31999..d8ad5357002d9 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -53,7 +53,12 @@ #define dont_test_bit(b,d) (0) -#define REJECT_HOTPLUG_TAX 1 +/* + * The SRCU bypass below skips srcu_read_lock() while the core retains its + * lockdep_assert_held(&gc->gpiodev->srcu) checks, so every gpiod_*() call + * splats under lockdep. Keep the optimisation for production builds only. + */ +#define REJECT_HOTPLUG_TAX (!IS_ENABLED(CONFIG_LOCKDEP)) #if REJECT_HOTPLUG_TAX