2003-01-13 05:32:24

by Madhavi

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Subject: writel hang problem


Hi

I am writing a device driver for a PCI device on linux 2.4.19 and i386
processor. I am initializing the memory mapped IO for this device in the
same way as it is shown in linux/drivers/net/pci-skeleton.c. I am using
readl and writel for accessing this PCI memory mapped IO.

The problem I am facing is -

When I try to write to a particular configuration register in this PCI MMIO
region, the system hangs. I am able to write properly and read back the
contents from other registers in this PCI MMIO region.

* Could anyone tell me why this might be happening?

* Could anyone tell me for what all reasons writel might hang?

When I request for an IRQ, I got an error which says:

"PCI: No IRQ known for interrupt pin A of device 00:e0.0. Using IRQ 11"

* Could this problem be related to the system hang problem in any way. Is this
IRQ problem fatal? I seem to be getting some interrupts from my device, though
they are not the same as expected.

Could anyone tell me what might be happening?

Thanks in advance.

regards
Madhavi.