Messages in this thread | | | From | Vladimir Oltean <> | Subject | Re: [PATCH v4] irqchip/ls-extirq: fix invalid wait context by avoiding to use regmap | Date | Thu, 18 Aug 2022 14:13:13 +0000 |
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Hi,
On Thu, Jul 28, 2022 at 05:42:54PM +0300, Vladimir Oltean wrote: > The irqchip->irq_set_type method is called by __irq_set_trigger() under > the desc->lock raw spinlock. > > The ls-extirq implementation, ls_extirq_irq_set_type(), uses an MMIO > regmap created by of_syscon_register(), which uses plain spinlocks > (the kind that are sleepable on RT). > > Therefore, this is an invalid locking scheme for which we get a kernel > splat stating just that ("[ BUG: Invalid wait context ]"), because the > context in which the plain spinlock may sleep is atomic due to the raw > spinlock. We need to go raw spinlocks all the way. > > Make this driver ioremap its INTPCR register on its own, and stop > relying on syscon to provide a regmap. Since the regmap we got from > syscon belonged to the parent and the newly ioremapped region belongs > just to us, the offset to the INTPCR register is now 0, because of the > address translation that takes place through the device tree. > > One complication, due to the fact that this driver uses IRQCHIP_DECLARE > rather than traditional platform devices with probe and remove methods, > is that we cannot use devres, so we need to implement a full-blown > cleanup procedure on the error path. > > Fixes: 0dcd9f872769 ("irqchip: Add support for Layerscape external interrupt lines") > Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> > ---
Just checking in on this patch to make sure it hasn't been forgotten.
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