From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gunter Grau Subject: [PATCH] ipipe: Fix ipipe level irq end Date: Thu, 17 Feb 2022 09:48:30 +0100 Message-Id: <20220217084830.712756-1-gunter.grau@philips.com> In-Reply-To: <94f8dc12-d019-4736-2423-bfacc6b3b0b2@siemens.com> References: <94f8dc12-d019-4736-2423-bfacc6b3b0b2@siemens.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain List-Id: Discussions about the Xenomai project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: xenomai@xenomai.org The following commit in the vanilla kernel introduced a check for the cached interrupt mask flag in mask_irq(): bf22ff45bed6 ("genirq: Avoid unnecessary low level irq function calls") This means if the flag is not serviced correctly the real bit in the hardware interrupt controller may not be cleared or set. The __ipipe_end_level_irq() function does not follow this rule. It unmasks the bit in the hardware without setting the cached flags accordingly. So after the first level interrupt is finished the mask cache has a wrong state. If now the next interrupt fires, the mask_irq() function will not really mask the interrupt in the hardware which causes a interrupt storm after reenabeling the hard irqs. The fix now also updates the shadow flag correctly. --- kernel/irq/chip.c | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c index 7c03e2931189..ff9a8b3f33db 100644 --- a/kernel/irq/chip.c +++ b/kernel/irq/chip.c @@ -988,6 +988,7 @@ void __ipipe_ack_level_irq(struct irq_desc *desc) void __ipipe_end_level_irq(struct irq_desc *desc) { desc->irq_data.chip->irq_unmask(&desc->irq_data); + irq_state_clr_masked(desc); } void __ipipe_ack_fasteoi_irq(struct irq_desc *desc) -- 2.25.1 ________________________________ The information contained in this message may be confidential and legally p= rotected under applicable law. The message is intended solely for the addre= ssee(s). If you are not the intended recipient, you are hereby notified tha= t any use, forwarding, dissemination, or reproduction of this message is st= rictly prohibited and may be unlawful. If you are not the intended recipien= t, please contact the sender by return e-mail and destroy all copies of the= original message.