Re: [PATCH v4 11/13] gpio: eic-sprd: use devm_atomic_notifier_chain_register()

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:

Pre-existing issues:
- [High] Unbinding one EIC sub-module will break interrupts for all other active sub-modules sharing the same parent IRQ.
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--- Patch [11]: [PATCH v4 11/13] gpio: eic-sprd: use devm_atomic_notifier_chain_register() ---

commit 55c8bafe72677fc98fb136d26d8a1306172a3b1f
Author: Eliav Farber [off-list ref]

gpio: eic-sprd: use devm_atomic_notifier_chain_register()

This commit replaces the atomic_notifier_chain_register() and
devm_add_action_or_reset() pattern with a single call to
devm_atomic_notifier_chain_register(). This removes the need for the custom
sprd_eic_unregister_notifier() callback.

[ ... ]

[Severity: High]
This is a pre-existing issue, but I noticed something about how the parent
interrupt is configured earlier in sprd_eic_probe().

The driver sets up the shared parent interrupt line as a non-shared chained
handler before registering the gpiochip:

    irq->parent_handler = sprd_eic_irq_handler;

Since the SPRD EIC hardware exposes up to 4 sub-modules that share the same
parent interrupt line, does unbinding one of these sub-modules break
interrupts for all other active sub-modules?

When a sub-module is unbound via sysfs or fails a late probe step, its
devres cleanup invokes gpiochip_remove(). This unconditionally calls
irq_set_chained_handler_and_data(parent_irq, NULL, NULL) which clears the
shared chained handler completely.

Will this result in a silent loss of GPIO interrupt functionality for the
remaining active EIC sub-modules sharing that parent IRQ?

 	}
 
 	sprd_eic->irq_nb.notifier_call = sprd_eic_irq_notify;
-	ret = atomic_notifier_chain_register(&sprd_eic_irq_notifier,
-					     &sprd_eic->irq_nb);
-	if (ret)
-		return dev_err_probe(dev, ret,
-				     "Failed to register with the interrupt notifier");
-
-	return devm_add_action_or_reset(dev, sprd_eic_unregister_notifier,
-					&sprd_eic->irq_nb);
+	return devm_atomic_notifier_chain_register(dev, &sprd_eic_irq_notifier,
+						   &sprd_eic->irq_nb);
 }

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Sashiko AI review · https://sashiko.dev/#/patchset/20260726101739.33170-1-farbere@amazon.com?part=11