Dear all,
I am developing a pci driver for a specific card.
It uses dma transfer and my problem is the
dma transfer goes well once insmod the module.
If unload(rmmod) and load(load) again, dma
transferring does not occur. Simply the dma
interrupt does not occur.
what i hv done is as follows.
When initializing
1. kmalloc for dma_buffer(64k)
2. clear and mask the interrupt
in write function
1. copy data to dma_buffer
2. bus_addr = dma_map_single()
3. set address, size, etc. in pci registers
4. clear and unmask the interrupt
4. start the dma transfer
in the interrupt routine
1. clear the interrupt
2. dma_unmap_single()
dma transfer goes well as long as first loading is there.
But in the second insmod dma fails.(interrupt fails).
Even if no dma transfer done in first insmod, dma transfer
fails in second loading .
If I restart my machine, then everything works again in
the first attempt.
My guess is a hardware problem.
can it be a problem of the driver or anything to do with
the kernel??
There is no register to reset dma.(no idea whether it is
necessary).
Thanks in advance.
Sumudu
