lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Fri, 12 Oct 2012 14:46:18 +0200 (CEST) From: Thomas Gleixner <tglx@...utronix.de> To: "Liu, Chuansheng" <chuansheng.liu@...el.com> cc: "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org> Subject: RE: [PATCH] genirq: for edge interrupt IRQS_ONESHOT support with irq thread On Fri, 12 Oct 2012, Liu, Chuansheng wrote: > > -----Original Message----- > > From: Thomas Gleixner [mailto:tglx@...utronix.de] > > Sent: Friday, October 12, 2012 8:32 PM > > To: Liu, Chuansheng > > Cc: linux-kernel@...r.kernel.org > > Subject: Re: [PATCH] genirq: for edge interrupt IRQS_ONESHOT support with irq > > thread > > > > On Fri, 12 Oct 2012, Chuansheng Liu wrote: > > > > > > In our system, there is one edge interrupt, and we want it to be > > > irq thread with IRQS_ONESHOT, and found in handle_edge_irq(), > > > even with IRQS_ONESHOT, the irq is still unmasked without care of > > > flag IRQS_ONESHOT. > > > > > > It causes IRQS_ONESHOT can not work well for edge interrupt, but also > > > after the irq thread finished with flag IRQS_ONESHOT, the irq will be > > > possible to be unmasked again, it should be messing mask/unmask logic. > > > > This is just wrong. By masking edge interrupts you will run into > > situations where you will lose interrupts. > > > > Can you please explain, why you want to mask your edge interrupt? > When I request_irq with irq thread handler and flag IRQS_ONESHOT, if > do not mask the edge interrupt, the primary handler and irq thread > maybe run at the same time, and in my real case it causes spin > deadlock. Then your code is simply wrong and you need to fix it instead of hacking a workaround into the core code. Locking is not that hard. > You means it is not right with IRQS_ONESHOT for edge interrupt? It's wrong. Simnply because you can lose interrupts. interrupt raised handle_edge_irq() mask_ack_irq() handle_event() wake irq thread reti irq thread runs handle device interrupt() <--- device issues edge irq unmask_irq() This interrupt is not delivered. So your device stops working. Not what you want, right? Thanks, tglx -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists