I get some trouble with the PCIe, problem occur with Pcie legacy interrupt, interrupt never fire.
i.MX6 with Apalis Evaluation Board
i.MX7 with Sabre RevD
Tested with Linux rel_imx_4.1.15_2.1.0_ga:
In this release all works also pcie legacy interrupt.
In this release legacy interrupt is broken, and not working.
MSI interrupt working.
My Pcie endpoint is a Ath9K and Ath10k.
Consideration over Linux Pcie Host driver.
The pci Host code in linux is hardly-changed from 4.1 to 4.9, so i think some change break, imx6/7 initialization.
A big change of Designware host drivers is example ATU support added.
In i.MX6/7 Manual is not described how PCIe RootComplex is connected i.MX6/7 platform.
Other Pcie Host drivers
Other Soc with "i suppose" same Pcie silicon implementations, initialize legacy interrupt, and handle it.
I'm referring to: pci-exynos.c and pci-keystone-dw.c
It also write some register, called IRQ_INTA_ASSERT and friends.
So, i think a help from NXP is required for let this works in Linux 4.9 and later.