405EP and pci_alloc_consistent()

Mark S. Mathews mark at linux-wlan.com
Fri Aug 20 03:11:30 EST 2004

Hi Folks,

I've got a wlan driver I'm running on a 405EP target with the 2.4.27
rsynch'd from the mvista site last week (my customer did that, I don't
have the exact details).

This device/driver relies on a dma'd 'control block' where all the queues
(heads,tails,metadata etc.) are managed.  We allocate that block with
pci_alloc_consistent().  I had some trouble with stale values until I
wrapped all the accesses of the block with invalidate_dcache_range()
before reads and flush_dcache_range() after writes.

I don't have a problem with the necessity to do all that, but it does
leave me a little uncomfortable.  I thought the pci_alloc_consistent call
should mark the tlb entrie(s) for that memory as non-cacheable.  Am I
missing something?



Mark S. Mathews

AbsoluteValue Systems      Web:    http://www.linux-wlan.com
721-D North Drive          e-mail: mark at linux-wlan.com
Melbourne, FL 32934        Phone:  321.259.0737
USA                        Fax:    321.259.0286

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