[U-Boot] non SPL boot on beagleboard-xm

Marek Vasut marek.vasut at gmail.com
Wed Jan 25 18:53:20 CET 2012


> On 01/25/2012 08:43 AM, Peter Meerwald wrote:
> > Hello Tom,
> > 
> >>> MLO/SPL + current u-boot breaks the USB ethernet patches (i.e. booting
> >>> via tftp)
> >> 
> >> Even with 'dc off' before you start usb?
> > 
> > I was not aware of the u-boot command 'dc off' -- yes, it solve my USB
> > ethernet problem
> > 
> > here is my story (from bisecting):
> > 
> > v2011.06 + Koen et al. patches (git://github.com/koenkooi/u-boot.git)
> > works
> > 
> > shortly afterwards, dcache was enabled (commit
> > c2dd0d45540397704de9b13287417d21049d34c6) and USB ethernet fails
> > 
> > v2011.09 works if using 'dc off' before 'usb start' (I tried it as a
> > recent non-SPL u-boot version)
> > 
> > u-boot current (137703b811502dfea364650fb3e17f20b4c21333) works as well
> > with 'dc off' before 'usb start'
> 
> So what's going on is that the dcache has been enabled now, but the USB
> stack is not safe, so we have to issue 'dcache off' (or 'dc off') before
> starting USB (or in other cases, networking).

Why would it not be safe? Because we don't have the unified cache ops in place 
yet? :-(

M


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