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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <2025060407-geologic-excuse-9ca5@gregkh>
Date: Wed, 4 Jun 2025 12:56:00 +0200
From: Greg KH <gregkh@...uxfoundation.org>
To: Guan-Yu Lin <guanyulin@...gle.com>
Cc: mathias.nyman@...el.com, gargaditya08@...e.com, kekrby@...il.com,
	jeff.johnson@....qualcomm.com, quic_zijuhu@...cinc.com,
	andriy.shevchenko@...ux.intel.com, ben@...adent.org.uk,
	broonie@...nel.org, quic_wcheng@...cinc.com,
	krzysztof.kozlowski@...aro.org, sumit.garg@...nel.org,
	linux-usb@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v14 0/4] Support system sleep with offloaded usb transfers

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