The below call chain generates "scheduling while atomic" backtrace and
causes system crash when Keystone 2 IRQ chip driver is used with RT-kernel:
gic_handle_irq()
|-__handle_domain_irq()
|-generic_handle_irq()
|-keystone_irq_handler()
|-regmap_read()
|-regmap_lock_spinlock()
|-rt_spin_lock()
The reason is that Keystone driver dispatches IRQ using chained IRQ handler
and accesses I/O memory through syscon->regmap(mmio) which is implemented
as fast_io regmap and uses regular spinlocks for synchronization, but
spinlocks transformed to rt_mutexes on RT.
Hence, convert Keystone 2 IRQ driver to use generic irq handler instead of
chained IRQ handler. This way it will be compatible with RT kernel where it
will be forced thread IRQ handler while in non-RT kernel it still will be
executed in HW IRQ context.
Cc: Suman Anna <s-anna@ti.com>
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Tested-by: Suman Anna <s-anna@ti.com>
Link: https://lkml.kernel.org/r/20161208233310.10329-1-grygorii.strashko@ti.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
Most interrupt flow handlers do not use the irq argument. Those few
which use it can retrieve the irq number from the irq descriptor.
Remove the argument.
Search and replace was done with coccinelle and some extra helper
scripts around it. Thanks to Julia for her help!
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
The irq argument of most interrupt flow handlers is unused or merily
used instead of a local variable. The handlers which need the irq
argument can retrieve the irq number from the irq descriptor.
Search and update was done with coccinelle and the invaluable help of
Julia Lawall.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
On Keystone SOCs, DSP cores can send interrupts to ARM
host using the IRQ controller IP. It provides 28 IRQ
signals to ARM. The IRQ handler running on HOST OS can
identify DSP signal source by analyzing SRCCx bits in
IPCARx registers. This is one of the component used by
the IPC mechanism used on Keystone SOCs.
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Link: https://lkml.kernel.org/r/1406126430-9978-1-git-send-email-grygorii.strashko@ti.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
