Re: 2.4.30 - USB serial problem

[Ian Leonard <ian@smallworld.cx>]

Pete Zaitcev wrote:
> On Thu, 26 May 2005 18:52:10 +0100, Ian Leonard <ian@smallworld.cx> wrote:
> 
> 
>>We recently upgraded from 2.4.24 to 2.4.28 and the problem described 
>>below appeared. I have tested it on 2.4.30 and the fault still exists.
>>[...]
>>Examining the packet that caused the problem showed it was very similar 
>>to the others but it contained 0x0a. This obviously stuck out as being a 
>>candidate for some sort of translation problem.
> 
> 
> The above looks almost too obvious but for this:
> 
> 
>>I also built a 2.4.28 kernel with the ftdi_sio and usbserial code from 
>>the 2.4.24 release. It also failed. This was a surprise and I am 
>>wondering of I did it correctly.
> 
> 
> Did you nail down a scenario which we can debug? Frankly it's not credible

Not as yet. As I indicated I can only test the problem at a remote site 
and I don't get much time to look at it.

> that transplanted usbserial and ftsi_sio would fail to work. I know that

I agree, it can't be the case. To prove that I hadn't just made a 
mistake, I transplanted the whole usb branch and it still failed. This 
really points to the user app - which is complex and I haven't got to 
the bottom of it. It's a multi-threaded library and I see it's doing 
some sort of packet requeuing based on a timer. I can't see what has 
changed but I am guessing it's a kernel timing issue. It would explain 
everything.

> I changed quite a bit between 2.4.24 and 2.4.28, but your experiment
> undoes that.

I think the usb is red herring - sorry about that. BTW, I see you have 
cc'd Ian (hi Ian). By coincidence we are using an MEV usb device.


-- 
Ian Leonard

Please ignore spelling and punctuation - I did.