Hi Pierre, On Tue, Nov 23, 2010 at 16:43:27, Pierre wrote: > Hi, > > I have tested the new driver using DMA mode on our custom DM355 board. I > replaced the linux 2.6.32 spi driver by this driver and it seemed to > work except for on point. The dm355 spi polling mode was correctly > working but the DMA mode was causing some communication problems. It > appeared that when dm355 was reading on the spi, it was actually > resending received data to our slave device on the spi bus, i didn't
Hmm, didn't really see this before. > fully checked what i am saying i am just supposing that it's what > occured. Anyway the behaviour was different in DMA and polling mode. I While working on the patches I noticed that DM355 has an errata regarding behavior of CSHOLD. In the patches, I take care of it by having DM355 define cshold_bug to true. Can you please make sure you have taken care of this as well while porting to 2.6.32? http://linux.davincidsp.com/pipermail/davinci-linux-open-source/2010-November/021045.html > didn't dig deep into the driver i just solved the problem (quick and > dirty) by setting tx buffer to zero in the spidev driver. > The problem can be caused by using SPIDAT as dma buffer when the tx > buffer is empty. > (If it helps i have tested before the spi patch V5 from Brian Niebuhr > and the problem was already there) How about with Brian's patch applied? Thanks, Sekhar _______________________________________________ Davinci-linux-open-source mailing list Davinci-linux-open-source@linux.davincidsp.com http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
