* Interrupts get disabled on USB access on MPC8272
@ 2008-09-26 15:36 David Beamonte
2008-09-26 16:31 ` Scott Wood
0 siblings, 1 reply; 2+ messages in thread
From: David Beamonte @ 2008-09-26 15:36 UTC (permalink / raw)
To: linuxppc-embedded
Hi,
I'm trying to make USB driver work on my MPC8272 with kernel 2.6.21.
The driver detects properly the root hub (the embedded controller), but
when it tries to communicate with a device, the system seems to hang.
I have debugged the kernel and what I can see is that, once the
processor tries to send a buffer of the USB controller, interrupts get
disabled. And so, there is no ethernet, serial port, or whatever way of
communication to the processor. With my debugger I can see that the
kernel keeps running and executing cpu_idle() and so on. Furtheremore,
jiffies increase, but no other interrupts occur.
Has anyone experienced a problem like this?
It seems to happen when buffers try to access external memory. Can it be
related to bus arbitration?
Regards,
David
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: Interrupts get disabled on USB access on MPC8272
2008-09-26 15:36 Interrupts get disabled on USB access on MPC8272 David Beamonte
@ 2008-09-26 16:31 ` Scott Wood
0 siblings, 0 replies; 2+ messages in thread
From: Scott Wood @ 2008-09-26 16:31 UTC (permalink / raw)
To: David Beamonte; +Cc: linuxppc-embedded
David Beamonte wrote:
> I have debugged the kernel and what I can see is that, once the
> processor tries to send a buffer of the USB controller, interrupts get
> disabled. And so, there is no ethernet, serial port, or whatever way of
> communication to the processor. With my debugger I can see that the
> kernel keeps running and executing cpu_idle() and so on. Furtheremore,
> jiffies increase, but no other interrupts occur.
It's probably waiting for an interrupt that never came.
> It seems to happen when buffers try to access external memory. Can it be
> related to bus arbitration?
Probably not; usually that sort of problem results in a hard lock-up.
-Scott
^ permalink raw reply [flat|nested] 2+ messages in thread
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2008-09-26 15:36 Interrupts get disabled on USB access on MPC8272 David Beamonte
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