Hi Markus, On Thursday 10 July 2008, Markus Klotzbücher wrote: > This patch fixes a potentially serious issue related to USB which was > discouvered by Martin Krause <[EMAIL PROTECTED]> and fixed for > ARM920T. Martin wrote: > > Turn off USB to prevent the host controller from writing to the > SDRAM while Linux is booting. This could happen, because the HCCA > (Host Controller Communication Area) lies within the SDRAM and the > host controller writes continously to this area (as busmaster!), for > example to increase the HccaFrameNumber variable, which happens > every 1 ms. > > This is a slightly modified version of the patch in order to shutdown > USB when booting on all architectures.
Yes, I remember hearing of this problem. I thought it was already fixed. Seems not to be the case. Please find a comment below. > Signed-off-by: Markus Klotzbuecher <[EMAIL PROTECTED]> > --- > common/cmd_bootm.c | 18 ++++++++++++++++++ > 1 files changed, 18 insertions(+), 0 deletions(-) > > diff --git a/common/cmd_bootm.c b/common/cmd_bootm.c By implementing this usb_stop() in do_bootm() you prevent this problem in many cases (e.g. Linux booting). But unfortunately not in all cases. For example "bootelf" or "bootvx" are not fixed. Can't this be solved in a different way. By calling usb_stop each time after an USB command completes. IIRC, this is how it is done in the U-Boot network implementation too. What do you think? Best regards, Stefan ===================================================================== DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: +49-8142-66989-0 Fax: +49-8142-66989-80 Email: [EMAIL PROTECTED] ===================================================================== ------------------------------------------------------------------------- Sponsored by: SourceForge.net Community Choice Awards: VOTE NOW! Studies have shown that voting for your favorite open source project, along with a healthy diet, reduces your potential for chronic lameness and boredom. Vote Now at http://www.sourceforge.net/community/cca08 _______________________________________________ U-Boot-Users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/u-boot-users
