Wolfgang Grandegger wrote:
On 06/30/2005 10:35 AM Jan Kiszka wrote:
Wolfgang Grandegger wrote:
OK, I realized as well, that I stumbeled over untested code. For some
Why the heck is this driver located in drivers/experimental? ;)
reason the kernel of FC 2 uses "zero-copy". I disabled DD_ZEROCOPY and
Could you check this modification in? It seems to be another unwanted
dependency on the Linux kernel config.
Well, in the driver rt_3c59.c there is:
#ifdef MAX_SKB_FRAGS
#define DO_ZEROCOPY 1
#else
#define DO_ZEROCOPY 0
#endif
And MAX_SKB_FRAGS is set somewhere in the Linux kernel, for all kernels
I guess. Well, I'm really puzzled how the rt_3c59 driver already worked
... good luck accessing invalid memory space?
Don't remember when this driver last transfered some packets
successfully. It was a contribution that we were never able to test and
maintain here. And then there are those documented RT issues due to
potential long delays in IRQ or xmit context.
now it works. Is the rtskb memory contiguous? How is it allocated?
Actually what the DMA engine of the 3c59 needs is a chain of memory
chunk address and size. I will look into this later on.
rtskbs, including the contained payload buffer, are allocated via
kmalloc. Therefore, the buffer consists of contignous memory and should
cause no DMA problems.
OK. Then there is no need for the frags stuff, as I see it today.
BTW: on my PowerPC test target I get frequently the message:
RTnet: unknown layer-3 protocol
Is the reason for is known? Corrupted data?
This indicates that packet arrive for which no handling protocol driver
is registered. Are you testing on a "public" (non-rt) network? Then this
is normal.
Jan
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