Messages in this thread | | | From | Benson Leung <> | Date | Thu, 1 Dec 2022 13:00:35 -0800 | Subject | Re: [PATCH] platform/chrome: Create new USB driver for RGB keyboard in ChromeOS devices |
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Hi Prashant,
On Thu, Dec 1, 2022 at 12:10 PM Prashant Malani <pmalani@chromium.org> wrote: > > Hi Won, > > On Wed, Nov 30, 2022 at 3:19 PM Won Chung <wonchung@google.com> wrote: > > > > Without any driver bound to RGB keyboard, it may not be suspended > > properly, preventing USB xHCI to be suspended and causing power drain. > > Create new USB driver for RGB keyboard so that it can be suspended > > properly. > > This seems like overkill. Can't you set this from USB's sysfs nodes > like power/control [1] ? > > [1] https://www.kernel.org/doc/html/latest/driver-api/usb/power-management.html#the-user-interface-for-dynamic-pm > > > Best regards, > > -Prashant
We're seeing some behavior where a bound driver is needed in order for this USB device to properly enter suspend state. Just manipulating the power/control and other sysfs nodes for this usb device when there's no driver in the kernel doesn't seem to affect the device's ability to drop into a usb low power state.
Also, I synced with Won about this offline, but the primary concern is not this prism usb device runtime suspending, it's actually it's ability to enter suspend state during system suspend. Right now, this internal usb device is keeping the whole system from entering lower S0iX states because it's not sleeping. This driver patch doesn't address that yet, but I'd like Won to dig down and see if he can get it suspending at suspend time too.
-- Benson Leung Staff Software Engineer Chrome OS Kernel Google Inc. bleung@google.com Chromium OS Project bleung@chromium.org
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