On Fri, Feb 21, 2020 at 09:50:42AM -0800, Florian Fainelli wrote:

On 2/21/20 9:11 AM, Mark Brown wrote:

quoted

The framework and/or driver can enumerate firmware information without
actually powering up the devices of course.

The issue is not enumeration, it is ensuring that you will be able to
establish the PCIe link with the EP. If there is no pci_device created
because the bus scanning returned a link down, there is not much that
can be done. Also the question is whether this logic belongs in the PCI
bus layer or the driver.

Given that the interface with the devices is all standardized I'd have
expected it to be in the bus code as a first pass.

quoted

I would not be surprised to learn that most systems just mark the device
supplies always on, it's not like the devices will be able to use them
normally anyway.

In the downstream PCIe driver which is this one is just a subset of
until we close the gap, we have some additional logical to determine
whether the EP device is wakeup enabled in order to leave its regulators
turned on during system sleep so as to permit Wake-on-WLAN for instance.

Is that just using standard PCI stuff or is it custom for embedded
applications?