2010/10/25 Marc-André Hébert <[email protected]>: > Hi, > > I would have replied directly to the original thread but I wasn't on > the mailing list back then. I wanted to report I encountered some > problems using the [PATCH v5 1/1] davinci: spi: replace existing > driver. > > I am currently using the Arago tree. I also applied the required DMA > patch > (http://linux.davincidsp.com/pipermail/davinci-linux-open-source/2010-March/018022.html). > I will try to test with linux-davinci but for that I would need more > work on the omapl138 spi first. > > Reading a block of at least 64k of data does not work with the new > driver. Here is how I reproduced (/dev/mtd1 is a spi flash with 256KB > sector size): > > dd if=/dev/mtd1 of=/dev/null count=1bs=32768 #OK > dd if=/dev/mtd1 of=/dev/null count=2bs=32768 #OK > dd if=/dev/mtd1 of=/dev/null count=1bs=65536 #Stalls in davinci_spi_txrx_bufs > > Trying with a block size of 128KB also fails. I am just unsure if this > failure is due to me using the Arago tree (maybe something else is > missing) or this is really an issue with the driver. If anybody else > can confirm or deny, it would be great. > > Regards > Marc > Think I identified part of the problem (from davinci_spi_txrx_bufs in driver/spi/davinci_spi.c): tx_param.a_b_cnt = davinci_spi->wcount << 16 | data_type;
With my example wcount equals the bs argument. So there is no way this can work if wcount requires more than 16 bits. Is the edma supposed to be limited to transfers with a len of 16 bits or less? Is the spi driver supposed to split the transfers or is there another way to set higher len bits? Marc _______________________________________________ Davinci-linux-open-source mailing list [email protected] http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
