From mboxrd@z Thu Jan 1 00:00:00 1970 From: linux@arm.linux.org.uk (Russell King - ARM Linux) Date: Tue, 16 Oct 2012 23:15:02 +0100 Subject: [PATCH] genirq: provide means to retrigger parent In-Reply-To: <1350425269-11489-1-git-send-email-khilman@deeprootsystems.com> References: <1350425269-11489-1-git-send-email-khilman@deeprootsystems.com> Message-ID: <20121016221502.GY28061@n2100.arm.linux.org.uk> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue, Oct 16, 2012 at 03:07:49PM -0700, Kevin Hilman wrote: > From: Thomas Gleixner > > Attempts to retrigger nested threaded IRQs currently fail because they > have no primary handler. In order to support retrigger of nested > IRQs, the parent IRQ needs to be retriggered. > > To fix, when an IRQ needs to be resent, if the interrupt has a parent > IRQ and runs in the context of the parent IRQ, then resend the parent. > > Also, handle_nested_irq() needs to clear the replay flag like the > other handlers, otherwise check_irq_resend() will set it and it will > never be cleared. Without clearing, it results in the first resend > working fine, but check_irq_resend() returning early on subsequent > resends because the replay flag is still set. > > Problem discovered on ARM/OMAP platforms where a nested IRQ that's > also a wakeup IRQ happens late in suspend and needed to be retriggered > during the resume process. > > Reported-by: Kevin Hilman > Tested-by: Kevin Hilman > [khilman at ti.com: changelog edits, clear IRQS_REPLAY in handle_nested_irq()] > Signed-off-by: Thomas Gleixner Umm, we also have the converse situation. We have platforms where the resend has to be done from the child IRQ, and the parent must not be touched. I hope that doesn't break those.