Hi Steve,
> You didn't answer my previous question:
> 
> > Is this device working with the kbase/DDK proprietary driver?

I don't know whether I used kbase/DDK,I only know I used the driver of
panfrost in linux 5.11.

> What you are describing sounds like a hardware integration issue, so
> it would be good to check that the hardware is working with the
> proprietary driver to rule that out. And perhaps there is something
> in the kbase for this device that is setting a chicken bit to 'fix'
> the coherency?

I don't have the proprietary driver,I only used driver in linux 5.11.

Thinks very much!

Chunyou.


?? Thu, 1 Jul 2021 11:15:14 +0100
Steven Price <steven.pr...@arm.com> ????:

> On 29/06/2021 04:04, Chunyou Tang wrote:


> > Hi Steve,
> >     thinks for your reply.
> >     I set the pte in arm_lpae_prot_to_pte(),
> > ***********************************************************************
> >     /*
> >      * Also Mali has its own notions of shareability wherein its
> > Inner
> >      * domain covers the cores within the GPU, and its Outer
> > domain is
> >      * "outside the GPU" (i.e. either the Inner or System
> > domain in CPU
> >      * terms, depending on coherency).
> >      */
> >     if (prot & IOMMU_CACHE && data->iop.fmt != ARM_MALI_LPAE)
> >             pte |= ARM_LPAE_PTE_SH_IS;
> >     else
> >             pte |= ARM_LPAE_PTE_SH_OS;
> > ***********************************************************************
> > I set pte |= ARM_LPAE_PTE_SH_NS.
> > 
> >     If I set pte to ARM_LPAE_PTE_SH_OS or
> >     ARM_LPAE_PTE_SH_IS,whether I use singel core GPU or multi
> > core GPU,it will occur GPU Fault.
> >     if I set pte to ARM_LPAE_PTE_SH_NS,whether I use singel core
> >     GPU or multi core GPU,it will not occur GPU Fault.
> 
> Hi,
> 
> So this is a difference between Panfrost and kbase. Panfrost (well
> technically the IOMMU framework) enables the inner-shareable bit for
> all memory, whereas kbase only enables it for some memory types (the
> BASE_MEM_COHERENT_LOCAL flag in the UABI controls it). However this
> should only be a performance/power difference (and AFAIK probably an
> irrelevant one) and it's definitely required that "inner shareable"
> (i.e. within the GPU) works for communication between the different
> units of the GPU.
> 
> You didn't answer my previous question:
> 
> > Is this device working with the kbase/DDK proprietary driver?
> 
> What you are describing sounds like a hardware integration issue, so
> it would be good to check that the hardware is working with the
> proprietary driver to rule that out. And perhaps there is something
> in the kbase for this device that is setting a chicken bit to 'fix'
> the coherency?
> 
> Steve


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