> -----Original Message----- > From: [email protected] [mailto:[email protected]] > On Behalf Of chris c > Sent: Tuesday, October 12, 2010 6:55 AM > To: [email protected] > Subject: Re: [U-Boot] Testing Data Cache for armv7 (beagleboard) > > Thanks for the replies. I didn't realize that the MMC module was > operating > in 1-bit mode inside U-boot. I'll concentrate on looking at that. Has > anybody done any work to try and get 4-bit mode working for OMAP3 in > U-boot?
[Ghorai] can you give a test using this patch series? This uses the generic mmc/sd driver for beagle board. And mmc/sd card will work at 4-bit, 48Mhz. http://www.mail-archive.com/[email protected]/msg38690.html > > Thanks, > Chris > > On Thu, Oct 7, 2010 at 1:04 PM, Wolfgang Denk <[email protected]> wrote: > > > Dear chris c, > > > > In message > <[email protected]<usuEyf4YuUVW > rrlu80bmrfprf%[email protected]>> > > you wrote: > > > > > > I was comparing time just by timing it manually. How did you > instrument > > > u-boot to display the time? > > > > That's no instrumentation of U-Boot, but just timestamping the output > > on the serial console. See for example > > ftp://ftp.denx.de/pub/tools/time_log > > > > > As for the small versus large file, I did the same test for 1MB of > data > > > using nand read and saw a x4 performance advantage. I also did a test > on > > > mmc with 100 MB file and saw no performance increase. Looks like file > > size > > > doesn't matter. > > > > > > So does that mean that MMC file loading will not benefit from dcache > > > enabled? Can anybody explain this? > > > > It depends on where the time is actually spent. If you have a slow > > (say, bit-banging) MMC driver and a low-performance CPU then the > > transfer from MMC might simply not depend as much on caches. It is > > wrong to check just a simple use case. Try a number of different > > operations, like umcompressing a large image in RAM or from NOR to > > RAM, or downloading over the net, or ... > > > > Best regards, > > > > Wolfgang Denk > > > > -- > > DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel > > HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany > > Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: [email protected] > > "Remember, Information is not knowledge; Knowledge is not Wisdom; > > Wisdom is not truth; Truth is not beauty; Beauty is not love; Love is > > not music; Music is the best." - Frank Zappa > > _______________________________________________ U-Boot mailing list [email protected] http://lists.denx.de/mailman/listinfo/u-boot
