On Fri, Aug 16, 2013 at 10:07 AM, Robert Nelson <robertcnel...@gmail.com> wrote: > On Fri, Aug 16, 2013 at 9:34 AM, Peter A. Bigot <p...@pabigot.com> wrote: >> On 08/16/2013 08:38 AM, Tom Rini wrote: >>> >>> On Wed, Aug 14, 2013 at 09:53:16PM -0500, Peter A. Bigot wrote: >>>> >>>> On 07/09/2013 02:43 AM, Naumann Andreas wrote: >>>>> >>>>> In chapter 'Advisory 2.1 USB Host Clock Drift Causes USB Spec >>>>> Non-compliance in Certain Configurations' of the TI Errata it is >>>>> recommended >>>>> to use certain div/mult values for the DPLL5 clock setup. >>>>> So far u-boot used the old 34xx values, so I added the errata >>>>> recommended values specificly for 36xx init only. >>>>> Also, the FSEL registers exist no longer, so removed them from init. >>>>> >>>>> Tested this on a AM3703 board with 19.2MHz oscillator, which previously >>>>> couldnt lock the dpll5 (kernel complained). As a consequence the EHCI USB >>>>> port wasnt usable in U-Boot and kernel. With this patch, kernel panics >>>>> disappear and USB working fine in u-boot and kernel. >>>>> >>>>> Signed-off-by: Andreas Naumann <anaum...@ultratronik.de> >>>> >>>> While this patch works with Linux that has been patched for this >>>> erratum, it will cause problems with some unpatched versions of >>>> Linux. >>> >>> Right. So Linux also needs to be patched for the erratum. >> >> >> Yes. My point was that if you update u-boot alone, then try to use it to >> boot an unpatched Linux that assumes CM_CLKSEL5_PLL has its power-on value, >> USB will not work. >> >> I think it's dangerous to assume that the mixture of an unpatched Linux with >> a patched u-boot will never occur, and the cause of the failure that results >> is pretty subtle. So whatever gets merged would be safer if it restored the >> default setting of CM_CLKSEL5_PLL prior to handing off control to Linux. > > Agree, we should not apply this, till we also have an 'approved' patch > for mainline linux posted. Right now we have a set of kernel hacks, > but no agreed on method as the kernel maintainer did not have a board > that suffered from the errata..
btw: here's a version that seems to work on v3.11-rc5: https://raw.github.com/RobertCNelson/armv7-multiplatform/v3.11.x/patches/omap_sprz319_erratum_v2.1/0001-hack-omap-clockk-dpll5-apply-sprz319e-2.1-erratum-kernel-3.11-rc2.patch Regards, -- Robert Nelson http://www.rcn-ee.com/ _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot