On Fri, Jan 16, 2015 at 08:41:06AM -0800, Tony Lindgren wrote: > * Russell King - ARM Linux <linux@xxxxxxxxxxxxxxxx> [150116 08:33]: > > On Fri, Jan 16, 2015 at 08:21:20AM -0800, Tony Lindgren wrote: > > > * Russell King - ARM Linux <linux@xxxxxxxxxxxxxxxx> [150115 09:22]: > > > > On Thu, Jan 15, 2015 at 07:28:39AM -0800, Tony Lindgren wrote: > > > > > * Russell King - ARM Linux <linux@xxxxxxxxxxxxxxxx> [150115 02:53]: > > > > > > I don't think we've proven a link there. While you're right that it > > > > > > causes the wrong interrupt to be claimed, I have two kernels here, > > > > > > both claim the same interrupt, one which is multi-platform and issues > > > > > > that strange warning, and one which targets only OMAP4 which doesn't. > > > > > > > > > > > > There's something else going on which causes the bus errors which we > > > > > > haven't found. > > > > > > > > > > I think it gets triggered if you enable PREEMPT. > > > > > > > > That's something which we can try to prove... build running now with > > > > CONFIG_PREEMPT=y > > > > > > Looks like you now have the omap_l3_noc error appear for sdp4430 in > > > your logs after enabling PREEMPT. > > > > > > I guess that means case closed for this one? > > > > I would still like to understand /why/ enabling preempt causes the error. > > Changing the preempt configuration really should not change what happens > > on the bus. (Think about it.) It's an indication that there is some > > other error present. > > We have a wrong irq number caused by $subject. And the wrong irq > gets triggered before the dma hardware is configured during dma > init. And then we get the invalid access error from omap_l3_noc. > > > Unfortunately, the OMAP hardware appears to make it impossible to > > determine what the access that caused the error was, so it looks like > > it's pretty much undebuggable. > > Yeah would be nice to have more info from omap_l3_noc. you can probably get more info by decoding all L4 instance errors. It's just not implemented anywhere. In this case, we should decode l4cfg which is who generated the error. -- balbi
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