Device Accessing Problem in 440GP
Vishwanath
vishwanath at mistralsoftware.com
Tue Dec 3 02:27:08 EST 2002
Hi All,
I am working on IBM 440GP based proprietry board using MVL 2.1 linux. I have
a device siiting on the EBC at 0x100100000 and I want to access it from the
user space. I use mmap call of my driver to do that. I have not initialized
the device. I have set the access parameters and controller registers of EBC
appropriately to access the device.
But when I make ioremap() call using,
ioremap64(0x100100000, 0x2000),
the function returns a valid pointer. But when I do a sample write and
read, I am not getting correct values. While I was debigging, I couldn't
find the TLB entry for the real address.
When I try to access the returned mmap() pointer, kernel says ,
do_wp_page: bogus page at address xxxx (page yyyy)
VM: killing process xxx
Does anyone know what could be the reason?
1. Do I have to initialize the device in setup_arch function ?
2. Do I have to explicitly create a TLB entry for the device ?
Hoping to get a response. I am stuck in the middle.
Thanks and regards,
Vishwa
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