[#5739] Blackfin serial dma is wonky after 2.6.32 upgrade
Submitted By: Mike Frysinger
2009-12-03 19:42:21 Close Date
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Summary: Blackfin serial dma is wonky after 2.6.32 upgrade
the serial core under went some changes that seems to have made our dma mode angry. boot up a BF537-STAMP_defconfig and see the misbehavior. RX seems to work fine, but TX lags way behind.
--- Mike Frysinger 2009-12-15 15:27:24
as a data point, vanilla 2.6.32 and current master (2.6.33-rc0) dont suffer this
problem. but i havent picked through the big pile of serial changes we have
locally to find out which one is causing the problem exactly.
--- Sonic Zhang 2009-12-15 23:07:44
Just figure out the cacheflush against the tx dma buffer should not be punt,
because it is allocated in cacheable memory region by kernel. Only the rx dma
buffer is allocated in uncacheable DMA region in bfin serial driver.
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