On Thu, Aug 29, 2013 at 01:07:36AM +0800, Greg Kroah-Hartman wrote: > On Wed, Aug 28, 2013 at 04:09:32PM +0800, Huang Rui wrote: > > On Wed, Aug 28, 2013 at 11:38:28AM +0800, Greg Kroah-Hartman wrote: > > > On Wed, Aug 28, 2013 at 11:13:12AM +0800, Huang Rui wrote: > > > > Yes, you're right. This issue is specific to the devices that use > > Pixart controller, and the Pixart controller is only used by mouse. > > That's why I filtered for usb mouse. > > So, to "fix" one specific controller, you drag in hundreds of thousands > of other devices as well? That's not ok. > > > Below answer is our HW guys' feedback. In cover letter, you would see > > more details. > > cover letters don't get applied to the kernel changelog, so they don't > count for much :) > > > [Q] Why the special devices are only mice? Would high speed devices > > such as 3G modem or USB Bluetooth adapter trigger this issue? > > - Current this sensitivity is only confined to devices that use Pixart > > controllers. This controller is designed for use with LS mouse > > devices only. We have not observed any other devices failing. There > > may be a small risk for other devices also but this patch (reset > > device in resume phase) will cover the cases if required. > > Then just do this "quirk" for Pixart controller devices. Don't penalize > everyone else. > > And have you worked with the Pixart company to "fix" this issue so that > future devices they create don't have this issue in it? > > > > That's why the USB core doesn't care about the device type, they are all > > > just "pipes". So please deal with it on that level, never do something > > > only depending on the "type" of device plugged into the system. > > > > > > > I got it. Do you mean if I want do filter usb devices by usb mouse, I > > should do it at hid or usbhid level? > > Neither, you could "miss" a mouse at those levels as well. > > Think about userspace control of USB devices, as well as mice that don't > use the HID layer (rare, but I've seen it happen.) > > Again, don't filter for a "mouse", filter for the controller that you > need to fix. > > > > Hint, I bet you didn't fix this bug in Windows this way, right? :) > > > > > > > Actually, this issue is found in Windows firstly, and we set a > > registry to force the driver to reset the device on S3 resume to work > > around it. Then I reproduce it in Linux OS, and make a same solution. :) > > So on Windows you do this for all mice devices? Or just Pixart devices? > If all mice devices, the Windows developers accepted such a change? > Windows has a backdoor of "force to reset on resume" in regedit like our kernel config. So it doesn't need change codes, just enable the backdoor. I don't know the details, I focus on linux usb driver. Thanks, Rui -- 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
