cvs commit: src/sys/platform/pc32/i386 busdma_machdep.c

Matthew Dillon dillon at
Tue Jun 5 11:01:44 PDT 2007

:>>   This fixes NATA's UDMA device support.  The UDMA dma controller is 
:>> limited
:>>   to a transfer size of 65536 bytes and address incrementation might not
:>>   carry over to bit 16.
:> Good catch!  Well hidden though.
:Indeed, I was staring myself blind on interrupts...
:         Thomas E. Spanjaard
:         tgen at

    I'll just say this is why sometimes being able to reproduce a problem
    locally, without having to debug it over email, can make a huge
    difference.  I've actually built DMA engines out of digital logic
    (like 15 years ago at this point!), so the moment I saw the corruption
    was on a page boundary and in page-sized chunks instead of in
    I/O-sized chunks I knew what the problem had to be.


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