David Brownell <[email protected]> writes: > The following four patches make the MMC/SD driver use EDMA > reload slots to make it get good throughput without needing > to enable CONFIG_MMC_BLOCK_BOUNCE: > > - Allocate EDMA slots when NR_SG > 1 ... at a typical > one page per scatterlist entry, NR_SG = 16 pages is > 64 KB, the same as the biggest bounce buffer. > > - Clean up some fault handling problems. With this, > I was often able to get 12 MByte/sec throughput on > a DM6446 EVM ... but that's out-of-spec and would > not even be reproducible on some days. > > - Some minor code shrinkage ... I happened to notice > needless indirections, code became smaller/clearer. > > - Kick in NR_SG=16 and use those slots. There's no > longer any reason to enable CONFIG_MMC_BLOCK_BOUNCE > with DaVinci; it won't kick in. > > If you were using CONFIG_MMC_BLOCK_BOUNCE before, you > won't notice much difference ... except that more CPU > time is available for Real Work, and sometimes you might > need fewer I/O requests to transfer the data. If you > didn't configure that, you'll see a significant speedup. > > - Dave > > p.s. If you recall that an earlier patch ripped out some > EDMA linkage support ... that was NR_SG=2 and didn't > work very well (AFAICT). > > p.p.s. After these merge, I think it's time for this > driver to go to mainline. So if anyone has other > patches for this code, or comments, pile on soon!!
Thanks, pushing this series today. Kevin _______________________________________________ Davinci-linux-open-source mailing list [email protected] http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
