On 05/30/2017 02:28 PM, Jeff Epler wrote: >> However, there already is a solution for this! The linux kernel has a >> SPI driver, which is quite good (used it before). It solves all the >> userspace problems and, to say the least, some very clever people have >> had a crack at this problem before. > [snip] > > We already have a driver for hostmot2 that uses /dev/spidev*, > hm2_spi. hm2_rpspi exists because its contributor stated that on > their system, hm2_spi did not perform adequately.
My guess is that it was on a Pi2. The Pi3 should perform better. The problem is that you cannot control the SMP behavior correctly from userspace, unless all interrupts are disabled and caching is taken into account. The only performance issue I can see is the asynchronous chip select. The original code in the hm2_rpspi is significantly slower in transfers due to synchronous write/read sequences. -- Greetings Bertho (disclaimers are disclaimed) ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
