Re: [PATCH net-next 05/10] lan78xx: Disable USB3 link power state transitions

On Tue, 24 Aug 2021 15:33:13 +0100 John Efstathiades wrote:

quoted

Do you expect the device-initiated transitions to always be causing
trouble or are there scenarios where they are useful?  

It's a particular problem on Android devices.

quoted

Having to recompile the driver is a middle ground rarely chosen
upstream. If the code has very low chance of being useful - let's
remove it (git will hold it forever if needed); if there are reasonable
chances someone will find it useful it should be configurable from user
space, or preferably automatically enabled based on some device match
list.  

I like the sound of the device match list but I don't know what you mean.
Is there a driver or other reference you could point me at that provides
additional info?

Depends on what the discriminator is. If problems happen with 
a particular ASIC revisions driver needs to read the revision
out and make a match. If it's product by product you can use
struct usb_device_id :: driver_info to attach metadata per 
device ID. If it's related to the platform things like DMI
matching are sometimes used. I have very limited experience 
with Android / embedded ARM so not sure what would work there.