> From: Trent Piepho > Are there any numbers to show if memory mapped read support is a > benefit in Linux? There is some question as to whether it's useful at > all or not. > > If it is, I think low latency for small reads is probably one of the > only advantages. To do that, you aren't going to want to deal with > device PM for every single read. It would make more sense to turn the > hardware on when the MTD device is opened and leave it on until > closed. > +1
Therefore early suggestions were to make 'MM_MODE' as default (if device enables it via DT). This means: (1) switch to 'SPI_MODE' _only_ when required for commands like mtd_erase, etc. and switch back to 'MM_MODE' when done. (2) And keep your controller clocks on. This would ensure that you do minimum config-switching when using MM_MODE. And would thus achieve low latency, and no driver intervention. Yes, real thruput numbers would help clear the picture here .. with regards, pekon ------------------------------------------------------------------------------ October Webinars: Code for Performance Free Intel webinars can help you accelerate application performance. Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from the latest Intel processors and coprocessors. See abstracts and register > http://pubads.g.doubleclick.net/gampad/clk?id=60135031&iu=/4140/ostg.clktrk _______________________________________________ spi-devel-general mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/spi-devel-general
