Problem faced while using workqueue in the character driver.

David Hawkins dwh at
Sat Jul 21 03:18:35 EST 2007

Hi Misbah,

> I am working on a character driver for FPGA, in which i am using a blocked
> read call on workqueue. The read call will be unblocked by the Interrupt
> from the Fpga to PPC Cpu.
> The problem is that if the process is in blocked mode and then an Interrupt
> occurs the system gives kernel Panic where as it get unblocked and start
> reading the data but very soon it gets crashed.
> Please send me your suggessins regarding the mentioned problem.

Er, without seeing the code, its a bit difficult to suggest

Perhaps you are using work-queues incorrectly?

Take a look at:


In the tar-ball

Which is described in:

There's also a more complex 'COBRA driver' here:

Having an example of a working driver that uses work-queues
might help you.


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