Re: [PATCH v14 0/4] Support system sleep with offloaded usb transfers

[Greg KH <gregkh@linuxfoundation.org>]

On Wed, Jun 04, 2025 at 08:23:06AM +0000, Guan-Yu Lin wrote:
> Wesley Cheng and Mathias Nyman's USB offload design enables a co-processor
> to handle some USB transfers, potentially allowing the system to sleep
> (suspend-to-RAM) and save power. However, Linux's System Sleep model halts
> the USB host controller when the main system isn't managing any USB
> transfers. To address this, the proposal modifies the system to recognize
> offloaded USB transfers and manage power accordingly. This way, offloaded
> USB transfers could still happen during system sleep (Suspend-to-RAM).
> 
> This involves two key steps:
> 1. Transfer Status Tracking: Propose offload_usage and corresponding apis
> drivers could track USB transfers on the co-processor, ensuring the
> system is aware of any ongoing activity.
> 2. Power Management Adjustment:  Modifications to the USB driver stack
> (xhci host controller driver, and USB device drivers) allow the system to
> sleep (Suspend-to-RAM) without disrupting co-processor managed USB
> transfers. This involves adding conditional checks to bypass some power
> management operations in the System Sleep model.

Is there a reason you aren't cc:ing the developers from a "big android
device company" that is currently testing and finding problems with this
patchset in their device testing?  I will require their signed-off-by or
tested-by in order to even consider accepting this patch series based on
the issues they seem to be finding with it in an
internal-company-bug-reporting-platform that I seem to be also copied
on.

thanks,

greg k-h