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Hi, all.
I'm testing Linux MMU version, on my NEEK.
http://www.nioswiki.com/linux It works fine and I can use "bash" shell. This is the evident proof that we are using the true 'fork' instead of 'vfork'.
May be this will depends on the version, but TSE driver claims an error and doesn't work on this design. The error is
ERROR: altera_tse.c:1666: request_mem_region() failed
I think that this error is caused by misunderstanding of the usage for the function request_mem_region(). Inside of the request_mem_region(), the function __request_region() is called. If the resource has been already registered, this function returns a non-NULL value, that is the pointer for its resource. But the resource 'sgdma_rx_base' is already registered in the initialization process, so this function returns the 'conflict' and
if (!request_mem_region(sgdma_rx_base, sgdma_rx_size, "altera_tse")) {
is always true. So I made a dirty patch,
if (!request_mem_region(sgdma_rx_base, sgdma_rx_size, "altera_tse")) {
reg_resource = __request_region(&iomem_resource, sgdma_rx_base, sgdma_rx_size, "altera_tse", 0);
if (reg_resource != NULL && reg_resource->flags & IORESOURCE_BUSY) {
printk(KERN_ERR "ERROR: %s:%d: request_mem_region() failed\n", __FILE__, __LINE__);
ret = -EBUSY;
goto out_sgdma_rx;
}
}
Moreover, the author is forgetting that the DMA is working in the physical address world,
so we need to set the pointers of descripters like
// desc->source = read_addr;
desc->source = virt_to_phys(read_addr);
// desc->destination = write_addr;
desc->destination = virt_to_phys(write_addr);
// desc->next = (unsigned int *)next;
desc->next = (unsigned int *)((unsigned long)next & 0x1fffffffUL);
and so on.
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Did you get any of these patches into the distribution? I am starting to work with the MMU and both of the Altera TSE drivers are broken with this version (more so than before ;)). I have fixed the atse.c driver to use the new macros for addresses, but need some more work on it to put ioremap()s in the right places because it uses phycal addresses for MAC control registers and descriptor memory. I am fairly new to driver programming so I am also a bit confused between ioremap, request_mem_region, phys_to_virt and all. Did you have to do anything else to get the altera_tse.c driver working?
Honored Contributor
