On Fri, 6 Sep 2019 at 11:14, Belisko Marek <marek.belisko@xxxxxxxxx> wrote: > > Hi, > > I'm trying to get some insights about how to debug emmc speed issue. > We're using board with am437x CPU using mainline 4.12 kernel (added > only devicetree for our custom board). eMMC is 8bit connect (using > sandisk SDINBDG4-8G-I1 chip). > > Issue is that when copying data from SD card to eMMC we get throughput > only ~300kB/s (it should be bit higher IIRC). I'm just looking for > some advice what to check and how to find out where issue can be > (still unsure if SW or HW). Thanks a lot. Mount debugfs and look at the ios node for the mmc host in question. There is information about clocks, busdwidth, etc. Kind regards Uffe
