Subject: Malta + USB on 2.4, anyone?

From: Jun Sun <[email-masked]>
Date: Wed, 30 Jul 2003 19:12:19 -0700

Has anybody tried USB on malta with 2.4 kernel?  I just found that
I got 0xff IRQ number and kernel panics.

Will look further tomorrow, but want to see if anybody knows about 
it first.

Also, the kgdb seems to be flaky.  Targets can send chars too fast
so that chars get lost.  It appears that the linux status register
might be lying about "transmitter buffer empty".  

Jun

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From: Chris Dearman <[email-masked]>
Date: Thu, 31 Jul 2003 10:53:06 +0100

> might be lying about "transmitter buffer empty".  

   I regularly use gdb @ 115200 on Malta and haven't noticed any problems.

	Chris

-- 
Chris Dearman          The Fruit Farm, Ely Road    voice +44 1223 706206
MIPS Technologies (UK) Chittering, Cambs, CB5 9PH  fax   +44 1223 706250

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From: "Maciej W. Rozycki" <[email-masked]>
Date: Thu, 31 Jul 2003 12:26:44 +0200 (MET DST)

> I got 0xff IRQ number and kernel panics.

 Possibly IRQ routing is broken -- the PIIX4 uses INTD for its USB
controller's interrupt.  For the Malta it should be routed to the IRQ11
input of the PIIX4's internal dual-8259A PIC.  What does `/sbin/lspci -vv
-s 00:0a.2' print?

-- 
+  Maciej W. Rozycki, Technical University of Gdansk, Poland   +
+--------------------------------------------------------------+
+        e-mail: [email-masked], PGP key available        +

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From: Jun Sun <[email-masked]>
Date: Thu, 31 Jul 2003 10:36:29 -0700

> input of the PIIX4's internal dual-8259A PIC.  What does `/sbin/lspci -vv

The output seems to say the same thing:

[email-masked]:~# lspci -vv -s 00:0a.2                                          
00:0a.2 USB Controller: Intel Corporation 82371AB PIIX4 USB (rev 01) (prog-if 00
 [UHCI])                                                                        
        Control: I/O+ Mem- BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Step
ping- SERR- FastB2B-                                                            
        Status: Cap- 66Mhz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort
- <MAbort- >SERR- <PERR-                                                        
        Latency: 32                                                             
        Interrupt: pin D routed to IRQ 11                                       
        Region 4: I/O ports at 1220 [size=32]                                   
                                                                                
Jun

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From: Jun Sun <[email-masked]>
Date: Thu, 31 Jul 2003 10:37:50 -0700

>    I regularly use gdb @ 115200 on Malta and haven't noticed any problems.

Yes.  I notice that kgdb generally works, but gets flaky when I hit
this particular problem.  That makes me wonder maybe something gets
very wrong with the controller chip....

Keep debugging ...

Jun

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From: Jun Sun <[email-masked]>
Date: Thu, 31 Jul 2003 11:15:06 -0700

>         Region 4: I/O ports at 1220 [size=32]                                   

Using the alternative JE driver sovles the problem.  

I suspect the main UHCI driver does not get cache flushing
or bus/virt address right.

Jun