kernel_samsung_sm7125

jenna

History

Thomas Gleixner 6d83f94db9 genirq: Disable the SHIRQ_DEBUG call in request_threaded_irq for now With CONFIG_SHIRQ_DEBUG=y we call a newly installed interrupt handler in request_threaded_irq(). The original implementation (commit `a304e1b8`) called the handler _BEFORE_ it was installed, but that caused problems with handlers calling disable_irq_nosync(). See commit `377bf1e4`. It's braindead in the first place to call disable_irq_nosync in shared handlers, but .... Moving this call after we installed the handler looks innocent, but it is very subtle broken on SMP. Interrupt handlers rely on the fact, that the irq core prevents reentrancy. Now this debug call violates that promise because we run the handler w/o the IRQ_INPROGRESS protection - which we cannot apply here because that would result in a possibly forever masked interrupt line. A concurrent real hardware interrupt on a different CPU results in handler reentrancy and can lead to complete wreckage, which was unfortunately observed in reality and took a fricking long time to debug. Leave the code here for now. We want this debug feature, but that's not easy to fix. We really should get rid of those disable_irq_nosync() abusers and remove that function completely. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Anton Vorontsov <avorontsov@ru.mvista.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Arjan van de Ven <arjan@infradead.org> Cc: stable@kernel.org # .28 -> .37		14 years ago
..
Kconfig	…
Makefile	…
autoprobe.c	…
chip.c	…
devres.c	…
dummychip.c	…
handle.c	…
internals.h	genirq: Prevent access beyond allocated_irqs bitmap	14 years ago
irqdesc.c	genirq: Prevent access beyond allocated_irqs bitmap	14 years ago
manage.c	genirq: Disable the SHIRQ_DEBUG call in request_threaded_irq for now	14 years ago
migration.c	…
pm.c	…
proc.c	…
resend.c	genirq: Prevent access beyond allocated_irqs bitmap	14 years ago
spurious.c	…