Hi I am trying to run the radeon and/or amdgpu drm driver on Freescale T2080RDB with an AMD e8860 GPU. I am using the linux-qoirq 5.10 kernel.
On modprobe, the driver tests the GPU ring command. It will fill a command buffer in system memory, then the GPU fetches the buffer and executes it. As a result a scratch register of the GPU is updated and the GPU increases its read pointer into the ring. Without fsl_pamu enabled, this test works fine without triggering any access error, which indicates all translation addresses are set up properly (outbound, inbound and law). But with fsl_pamu enabled, this test fails. The command buffer isn't executed, neither the scratch value nor the read pointer into the ring are updated. Moreover, the fsl_pamu driver doesn't trigger any access error. My guess is a cache coherency issue. The GPU doesn't fetch from system memory the proper values hence nothing is executed. However it's only a guess as I have no expertise on the PAMU setup for this processor. Any suggestions? Regards Thomas
_______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
