On Fri, Aug 12, 2016 at 10:32 AM, Rob Clark <robdclark@xxxxxxxxx> wrote: > On Fri, Aug 12, 2016 at 9:48 AM, Sricharan <sricharan@xxxxxxxxxxxxxx> wrote: >> Hi, >> >>>>>>>> btw, the current state, at least on linaro integration branch, fault >>>>>>>> handling doesn't work so well (ie. device never gets resumed).. which >>>>>>>> is a bit unfortunate for a gpu (and results in a *lot* of rebooting on >>>>>>>> my part when debugging userspace). I haven't had time yet to compare >>>>>>>> to the ancient downstream driver, but not sure if you have any ideas? >>>>>>>> >>>>>>>> I guess probably disabling stall on fault would help. But I'm not >>>>>>>> even getting the "Fault occurred in context.." prints. Seeing the >>>>>>>> fault iova is pretty useful since that plus gpu cmdstream trace helps >>>>>>>> me figure out which texture/etc is being accessed out of bounds. >>>>>>> >>>>>>>fyi, it looks like it is not getting any fault irq.. it's *possible* >>>>>>>that I screwed up the irq #'s when translating from downstream, so you >>>>>>>might want to double check that. I thought I had it right, I assume I >>>>>>>would have noticed during piglit runs if fault recovery wasn't working >>>>>>>(since the result is that *everything* after the faulting test would >>>>>>>have failed since gpu is wedged with no access to memory), but it was >>>>>>>long enough ago that I can't claim that definitively. >>>>>>> >>>>>>>If you need an easy way to trigger a gpu fault, msmtest is a good way, >>>>>>>change this line: >>>>>>> >>>>>>> https://github.com/freedreno/msmtest/blob/master/msmtest.c#L247 >>>>>>> >>>>>>>from OUT_RELOC() to OUT_RING(ring, 0x00000000) will trigger a fault. >>>>>>> >>>>>> So for the irq to be triggered, 'non-secure' irq line has to be >>>>>> populated in DT. There is a 'secure'and 'non-secure' irq lines for these iommus >>>>>> and non-secure irq number is secure + 1. I tested this by having a 'return 0' >>>>>> from the msm_iommu_map (no mapping), and the faults were getting triggered. >>>>>> >>>>>> Can you share me your dts data ? >>>>>> >>>>> >>>>>I think this is what you want: >>>>> >>>>>https://github.com/freedreno/kernel-msm/blob/integration-linux-qcomlt/arch/arm/boot/dts/qcom-apq8064.dtsi#L2008 >>>>> >>>>>I haven't tested a display fault, so I suppose it is possible that >>>>>irq's are working for some iommu instances but not others? >>>> >>>> So in your DT, for gfx3d, the non-secure line is '70' and not '69' (This is secure) . >>>> Infact only '70' should be populated. The driver sets the irq line based on resource 0. >>>> This applies for all iommu nodes in your DT. (only the second irq line is needed). >>> >>>ahh, that would explain. >>> >>>Is it better to remove the extra entry, or should I just swap them >>>all? Ie. might there be some point in the future where the driver >>>would want both? >> I feel better to have one. Not sure why the secure irq was added in first >> place in the downstream data and it would setup/handled by the TZ > > Ok, getting further.. still seems like the gpu is not getting resumed, > but at least we are getting a fault interrupt.. ok, seems like we need: ------- diff --git a/drivers/iommu/msm_iommu.c b/drivers/iommu/msm_iommu.c index b09692b..f6f596f 100644 --- a/drivers/iommu/msm_iommu.c +++ b/drivers/iommu/msm_iommu.c @@ -628,6 +628,7 @@ irqreturn_t msm_iommu_fault_handler(int irq, void *dev_id) pr_err("Interesting registers:\n"); print_ctx_regs(iommu->base, i); SET_FSR(iommu->base, i, 0x4000000F); + SET_RESUME(iommu->base, i, 1); } } __disable_clocks(iommu); ------- with that it seems like it kinda/mostly recovers, although there is still a bit of strangeness.. BR, -R -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
