On Thu, Nov 07, 2013 at 01:18:54AM +0000, Liu, Chuansheng wrote: > Hello, > > > -----Original Message----- > > From: Tejun Heo [mailto:hte...@gmail.com] On Behalf Of t...@kernel.org > > Sent: Thursday, November 07, 2013 8:52 AM > > To: Liu, Chuansheng > > Cc: Greg KH; dmitry.torok...@gmail.com; linux-kernel@vger.kernel.org > > Subject: Re: [PATCH] devres: Freeing the drs after all release() are called > > > > Hello, > > > > On Thu, Nov 07, 2013 at 12:36:56AM +0000, Liu, Chuansheng wrote: > > > Yes, I knew I can put the code always like below: > > > A = devm_kzalloc(); > > > C = devm_kzalloc(); > > > ... > > > B= devm_request_threaded_irq(isr_handler); > > > > > > But, the above is just one simple coding prototype, if there are many > > > calling: > > > E -- > F -- > D -- >... then to devm_kzalloc(). > > > > > > To be honest, it will make code too hard to always adapt the rule? > > > And I trying to find out every potential devm_kzalloc() before irq > > > requesting. > > > > It isn't a good idea to paper over existing bugs from upper layer. > > You realize that the above code sequence is already buggy during init > > unless there's something explicitly blocking generation of irqs until > > init is complete, right? The right thing to do would be either > > reordering the operations or wrapping the operation which unblocks irq > > at the end of init with devres so that irq gets blocked before the > > rest of release proceeds. > > > > What we must *NOT* do is working around existing bugs in a half-assed > > way from midlayer. > > Yes, doing the right order initialization is always right thing. > But normally when we hit the panic during shutdown/reboot like below: > PAGE FAULT XXX 0x12345678 > > It is really difficult to debug. > So at least, could we have method to expose these hidden issues?
Have you enabled timer debugging? I think there's an irq debugging option as well. We aren't going to paper over driver bugs by changing the kernel core, sorry. Consider this patch dropped. greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
