On Tue, 2018-11-20 at 17:56 +0100, Stefan Agner wrote: > Define the length of the DBI registers. This makes sure that > the kernel does not access registers beyond that point, avoiding > the following abort on a i.MX 6Quad: > # cat > /sys/devices/soc0/soc/1ffc000.pcie/pci0000\:00/0000\:00\:00.0/config > [ 100.021433] Unhandled fault: imprecise external abort (0x1406) > at 0xb6ea7000 > ... > [ 100.056423] PC is at dw_pcie_read+0x50/0x84 > [ 100.060790] LR is at dw_pcie_rd_own_conf+0x44/0x48 I don't know exactly where this limitation comes from, I can indeed reproduce a stack dump when dumping pci config from /sys/ Unfortunately this seems to block access to registers used for functionality like interrupts. For example dw_handle_msi_irq does: dw_pcie_rd_own_conf(pp, PCIE_MSI_INTR0_STATUS + (i * MSI_REG_CTRL_BLOCK_SIZE), 4, &val); where PCI_MSI_INTR0_STATUS is 0x830. There are more accesses like this. Testing on 6dl-sabreauto (dts change required) with an ath9k pcie card with your series I sometimes get "irq 295: nobody cared" on boot. Maybe I'm missing something? -- Regards, Leonard
