On Wed, 31 Mar 2010 12:33:01 +0530 kishore kadiyala <kishorek.kadiyala@xxxxxxxxx> wrote: > This patch improves low speeds for SD cards. > OMAP-MMC controller's can support maximum bus width of '8'. > when bus width is mentioned as "8" in controller data,the SD > stack will check whether bus width is "4" and if not it will > set bus width to "1" and there by degrading performance. > This patch fixes the issue and improves the performance of > SD cards. > > Signed-off-by: Kishore Kadiyala <kishore.kadiyala@xxxxxx> > Signed-off-by: Venkatraman S <svenkatr@xxxxxx> > Acked-by: Madhusudhan Chikkature <madhu.cr@xxxxxx> > > --- > In V2 : Appended Signed-off by Venkat and Ack by Madhu > > Here are my experiment numbers, on a Class 6 SDHC card: > Read peformance is increased by 220% > Write Performance is increased by 52% > Some results from the BeagleBoard and 2 GB SD card: sync; time (dd if=/dev/zero of=`date +%s`.bin bs=1M count=100; sync) -> ~40 % improvement over 4 writes. time dd if=12700xxxxx.bin of=/dev/null -> ~96 % improvement over 4 reads. Feel free to add my tested-by. Tested-by: Jarkko Nikula <jhnikula@xxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
