Linux Kernel PCI Suspend/Resume Support Vulnerability on i.MX6QDL

A vulnerability in the Linux kernel's PCI suspend/resume support on the i.MX6QDL platform has been addressed. This issue, documented in the NXP errata ERR005723, caused the suspend/resume functionality to fail, particularly when a PCIe device was connected. The vulnerability arose because critical registers were modified, disrupting PCIe functionality, and certain drivers, such as ath10k and iwlwifi, would crash upon resuming. The patch resolves these issues by aligning the suspend/resume sequences with those used by other i.MX devices, resetting the connected PCIe device when possible to prevent driver crashes.

Impact

Without this patch, i.MX6QDL devices would experience a kernel hang and an error message indicating that the system was unable to change the power state of connected PCIe devices from a low-power state to an active state, rendering the devices inaccessible. This issue could cause crashes for drivers like ath10k and iwlwifi upon resume, as the drivers would fail to access the PCIe device properly.