Messages in this thread | | | Date | Mon, 03 Oct 2022 16:28:10 +0100 | From | Marc Zyngier <> | Subject | Re: [PATCH v4] irqchip/ls-extirq: fix invalid wait context by avoiding to use regmap |
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On Mon, 03 Oct 2022 10:45:43 +0100, Vladimir Oltean <vladimir.oltean@nxp.com> wrote: > > Hi Marc, Arnd, > > On Thu, Aug 18, 2022 at 05:13:09PM +0300, Vladimir Oltean wrote: > > 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. > > Is there something else I need to do such that this patch gets accepted?
No, it just went under the radar. I would have liked an ack from Rasmus, but this has been there for long enough.
I'll queue this as a fix for 6.1.
Thanks,
M.
-- Without deviation from the norm, progress is not possible.
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