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[v4,0/2] usb: override hub device bInterval with device

Message ID 20191203101521.198914-1-ikjn@chromium.org (mailing list archive)
Headers show
Series usb: override hub device bInterval with device | expand

Message

Ikjoon Jang Dec. 3, 2019, 10:15 a.m. UTC 
This patchset enables hard wired hub device to use different bInterval
from its descriptor when the hub has a combined device node.

When we know reducing autosuspend delay for built-in HIDs is better for
power saving, we can reduce it to the optimal value. But if a parent hub
has a long bInterval, mouse lags a lot from more frequent autosuspend.
So this enables overriding bInterval for a hard wired hub device only
when we know that reduces the power consumption.

Changes in v4
- use of_property_read_u32() instead of of_property_read_u8()

Ikjoon Jang (2):
  dt-bindings: usb: add "hub,interval" property
  usb: overridable hub bInterval by device node

 Documentation/devicetree/bindings/usb/usb-device.txt | 4 ++++
 drivers/usb/core/config.c                            | 9 +++++++++
 2 files changed, 13 insertions(+)

Comments

Johan Hovold Dec. 3, 2019, 4:40 p.m. UTC | #1 
On Tue, Dec 03, 2019 at 06:15:21PM +0800, Ikjoon Jang wrote:
> This patchset enables hard wired hub device to use different bInterval
> from its descriptor when the hub has a combined device node.
> 
> When we know reducing autosuspend delay for built-in HIDs is better for
> power saving, we can reduce it to the optimal value. But if a parent hub
> has a long bInterval, mouse lags a lot from more frequent autosuspend.
> So this enables overriding bInterval for a hard wired hub device only
> when we know that reduces the power consumption.
> 
> Changes in v4
> - use of_property_read_u32() instead of of_property_read_u8()

What changed in the previous versions?

Johan
Ikjoon Jang Dec. 4, 2019, 2:46 a.m. UTC | #2 
On Wed, Dec 4, 2019 at 12:40 AM Johan Hovold <johan@kernel.org> wrote:
>
> On Tue, Dec 03, 2019 at 06:15:21PM +0800, Ikjoon Jang wrote:
> > This patchset enables hard wired hub device to use different bInterval
> > from its descriptor when the hub has a combined device node.
> >
> > When we know reducing autosuspend delay for built-in HIDs is better for
> > power saving, we can reduce it to the optimal value. But if a parent hub
> > has a long bInterval, mouse lags a lot from more frequent autosuspend.
> > So this enables overriding bInterval for a hard wired hub device only
> > when we know that reduces the power consumption.
> >
> > Changes in v4
> > - use of_property_read_u32() instead of of_property_read_u8()
>
> What changed in the previous versions?

changes in the previous versions:
v4: use of_property_read_u32() instead of of_property_read_u8()
v3: errata fixed "hub, interval" --> "hub,interval"
v2: do not use unlikely() macro, commit message

>
> Johan