From: H. Nikolaus Schaller hns@goldelico.com
[ Upstream commit 5f5ac460dfe7f4e11f99de9870f240e39189cf72 ]
commit bb38919ec56e ("PCI: imx6: Add support for i.MX6 PCIe controller") added a fault hook to this driver in the probe function. So it was only installed if needed.
commit bde4a5a00e76 ("PCI: imx6: Allow probe deferral by reset GPIO") moved it from probe to driver init which installs the hook unconditionally as soon as the driver is compiled into a kernel.
When this driver is compiled as a module, the hook is not registered until after the driver has been matched with a .compatible and loaded.
commit 415b6185c541 ("PCI: imx6: Fix config read timeout handling") extended the fault handling code.
commit 2d8ed461dbc9 ("PCI: imx6: Add support for i.MX8MQ") added some protection for non-ARM architectures, but this does not protect non-i.MX ARM architectures.
Since fault handlers can be triggered on any architecture for different reasons, there is no guarantee that they will be triggered only for the assumed situation, leading to improper error handling (i.MX6-specific imx6q_pcie_abort_handler) on foreign systems.
I had seen strange L3 imprecise external abort messages several times on OMAP4 and OMAP5 devices and couldn't make sense of them until I realized they were related to this unused imx6q driver because I had CONFIG_PCI_IMX6=y.
Note that CONFIG_PCI_IMX6=y is useful for kernel binaries that are designed to run on different ARM SoC and be differentiated only by device tree binaries. So turning off CONFIG_PCI_IMX6 is not a solution.
Therefore we check the compatible in the init function before registering the fault handler.
Link: https://lore.kernel.org/r/e1bcfc3078c82b53aa9b78077a89955abe4ea009.167838099... Fixes: bde4a5a00e76 ("PCI: imx6: Allow probe deferral by reset GPIO") Fixes: 415b6185c541 ("PCI: imx6: Fix config read timeout handling") Fixes: 2d8ed461dbc9 ("PCI: imx6: Add support for i.MX8MQ") Signed-off-by: H. Nikolaus Schaller hns@goldelico.com Signed-off-by: Lorenzo Pieralisi lpieralisi@kernel.org Reviewed-by: Richard Zhu hongxing.zhu@nxp.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/pci/controller/dwc/pci-imx6.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c index 1dde5c579edc8..47db2d20568ef 100644 --- a/drivers/pci/controller/dwc/pci-imx6.c +++ b/drivers/pci/controller/dwc/pci-imx6.c @@ -1402,6 +1402,13 @@ DECLARE_PCI_FIXUP_CLASS_HEADER(PCI_VENDOR_ID_SYNOPSYS, 0xabcd, static int __init imx6_pcie_init(void) { #ifdef CONFIG_ARM + struct device_node *np; + + np = of_find_matching_node(NULL, imx6_pcie_of_match); + if (!np) + return -ENODEV; + of_node_put(np); + /* * Since probe() can be deferred we need to make sure that * hook_fault_code is not called after __init memory is freed