about mouse lost synchronization

about mouse lost synchronization

[Yao-Chung Chang]

Dear all

I've implemented a ps/2 serio driver that uses GPIO (two GPIO pins). Each 

bit is triggered by GPIO interrupt. When in console mode, GPM works

fine, and I can see the mouse cursor moves correctly. But When entering 

GUI, say QT or microwindows, the following messages occurred:

Mouse at xxxxx/serio0/input0 lost synchronization, throwing 1 bytes away.
..
Mouse at xxxxx/serio0/input0 lost synchronization, throwing 1 bytes away.

Mouse at xxxxx/serio0/input0 lost synchronization, throwing 2 bytes away.

And the mouse cursor is floating and moves incorrectly. 

What is the criteria that kernel think the mouse packet is lost of sync.?

                                        Regards,
                                                ycchang
 

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Re: about mouse lost synchronization

[Dmitry Torokhov]

Hi,

On Wed, May 13, 2009 at 03:27:33PM +0800, Yao-Chung Chang wrote:
> Dear all
> 
> I've implemented a ps/2 serio driver that uses GPIO (two GPIO pins). Each 
> 
> bit is triggered by GPIO interrupt. When in console mode, GPM works
> 
> fine, and I can see the mouse cursor moves correctly. But When entering 
> 
> GUI, say QT or microwindows, the following messages occurred:
> 
> Mouse at xxxxx/serio0/input0 lost synchronization, throwing 1 bytes away.
> ..
> Mouse at xxxxx/serio0/input0 lost synchronization, throwing 1 bytes away.
> 
> Mouse at xxxxx/serio0/input0 lost synchronization, throwing 2 bytes away.
> 
> And the mouse cursor is floating and moves incorrectly. 
> 
> What is the criteria that kernel think the mouse packet is lost of sync.?
> 

When interrupts are delayed for too long the krenel thinks that it
missed a few bytes and complains.

-- 
Dmitry