Re: [PATCH 2/3] usb: Take attribute avoid_reset_quirk out of usb device's attribute group

[Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>]

On Thu, 2 Aug 2012, Lan Tianyu wrote:

> A summary about what we should do now after such long discussion. If I 
> lost something or miss something, please correct me.
> 
> 1) Add "auto" option to each port's power policy sysfs attribute. When
> set to "auto", those ports which have never been attached with devices
> will be power off immediately.

No.  Ports will be powered down only if it's impossible to attach a 
device, that is, if PortIsConnectable is clear.  As a safety check, you 
should also verify that no device is currently attached.

> 2)Expose the ACPI PortIsConnectable, UserVisible (If it was on the ACPI 
> platfrom) and usb DeviceRemovable flag via sysfs attributes.
> 
> 3)Root-hub set port's DeviceRemovable flag where PortIsConnectable and 
> UserVisible are clear.

Set DeviceRemovable whenever UserVisible is set.  Right now ehci-hcd 
and uhci-hcd always set DeviceRemovable to 0.

> 4)Add QUIRK_POWEROFF_MORPHS flags for those devices which retain
> important settings across a reset but lose them when power is removed.

This flag doesn't care about resets.  It applies to any device which 
loses important settings when bus power is removed.

Alan Stern

--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html