Hi Jeroen, After debugging a bit more, I found that in our code, we didn't set the RAM size correctly (so no real RAM section was setup for caching). Fixing this fixed our time to 2.4 seconds (U-boot still took 1.8 sec).
Adding your SRAM patch (modified, since AM335x has more SRAM), The load time dropped from 2.4 -> 1.9 seconds. So adding this small area saved half a second! I write off the remaing difference (1.8 vs 1.9 seconds) to code differences between our SPL and U-boot nand functions. Thanks, Bas _____ From: Tom Rini [mailto:tr...@ti.com] To: Jeroen Hofstee [mailto:jer...@myspectrum.nl] Cc: Wolfgang Denk [mailto:w...@denx.de], bas.van.den.b...@alten.nl, u-boot@lists.denx.de Sent: Fri, 21 Jun 2013 20:56:53 +0100 Subject: Re: [U-Boot] AM335x: enabling datacache in SPL slows down system? On Fri, Jun 21, 2013 at 08:46:47PM +0200, Jeroen Hofstee wrote: > Hello Wolfgang, > > On 06/21/2013 07:33 AM, Wolfgang Denk wrote: > >We observed the very same issue with the verry first prototype > >implementation of Falcon mode on an AM3517 based board. [..] > For the am3517 the only thing needed is to add SRAM > to the known memory. See [1], that should change the > cache misses (which likely cause the extra delays) to > actual caches. U-boot only adds the detected memory > and since U-boot is running from DRAM and SPL is not, > the difference seems obvious. This would be my guess as folks have done functional but not mainlineable changes in this direction, as well as DMA, before. -- Tom
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