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. ÓÚ Thu, 1 Jul 2021 11:15:14 +0100 Steven Price <steven.price@xxxxxxx> дµÀ: > 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
