[U-Boot] [U-Boot, v2, 4/4] arm: am33xx: Add support for mulitiple PLL input frequencies

[Tom Rini <trini@konsulko.com>]

On Fri, Jun 09, 2017 at 09:53:14PM +0200, Emmanuel Vadot wrote:
> On Fri, 9 Jun 2017 15:13:05 -0400
> Tom Rini <trini@konsulko.com> wrote:
> 
> > On Fri, Jun 09, 2017 at 05:55:10PM +0200, Heiko Schocher wrote:
> > > Hello Tom,
> > > 
> > > Am 09.06.2017 um 13:20 schrieb Tom Rini:
> > > >On Fri, Jun 09, 2017 at 12:22:44PM +0200, Heiko Schocher wrote:
> > > >>Hello Lokesh,
> > > >>
> > > >>Am 09.06.2017 um 11:25 schrieb Lokesh Vutla:
> > > >>>
> > > >>>
> > > >>>On Friday 09 June 2017 09:30 AM, Heiko Schocher wrote:
> > > >>>>Hello Tom,
> > > >>>>
> > > >>>>Am 09.06.2017 um 02:45 schrieb Tom Rini:
> > > >>>>>On Thu, Jun 08, 2017 at 10:17:09AM +0530, Lokesh Vutla wrote:
> > > >>>>>>
> > > >>>>>>
> > > >>>>>>On Thursday 08 June 2017 12:20 AM, Emmanuel Vadot wrote:
> > > >>>>>>>On Fri, 12 May 2017 13:20:50 -0400
> > > >>>>>>>Tom Rini <trini@konsulko.com> wrote:
> > > >>>>>>>
> > > >>>>>>>>On Fri, May 05, 2017 at 12:59:10PM +0530, Lokesh Vutla wrote:
> > > >>>>>>>>
> > > >>>>>>>>>am335x supports various sysclk frequencies which can be determined
> > > >>>>>>>>>using sysboot pins. PLLs should be configures based on this
> > > >>>>>>>>>sysclk frequency. Add PLL configurations for all supported
> > > >>>>>>>>>frequencies.
> > > >>>>>>>>>
> > > >>>>>>>>>Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
> > > >>>>>>>>>Reviewed-by: Tom Rini <trini@konsulko.com>
> > > >>>>>>>>
> > > >>>>>>>>Applied to u-boot/master, thanks!
> > > >>>>>>>>
> > > >>>>>>>>--
> > > >>>>>>>>Tom
> > > >>>>>>>
> > > >>>>>>>   Hello,
> > > >>>>>>>
> > > >>>>>>>   This appears to break beaglebone black support, reverting this commit
> > > >>>>>>>make u-boot works again.
> > > >>>>>>
> > > >>>>>>hmm..I see the problem. Here we are hard coding MPU freq to 1GHz even
> > > >>>>>>efuse say it is not supported(I am not sure why this is being done, may
> > > >>>>>>be Tom can give more details). Even in kernel I see that cpufreq is
> > > >>>>>>reading efuse to determine mpu frequency. Now that we have jitter
> > > >>>>>>optimized pll configurations, looks like unsupported freq is causing an
> > > >>>>>>issue. Can you see if the below patch helps?
> > > >>>>>
> > > >>>>>Well, in the kernel, did anyone poke the Beagleboard folks about this,
> > > >>>>>before pushing the change?  There's BBB shipping with chips that did not
> > > >>>>>have their efuses set, hence the way things were structured in U-Boot.
> > > >>>>
> > > >>>>I have runnint tbot tests on a BBB [1] ... and yes, currently test
> > > >>>>is red = bad ... :-(
> > > >>>>
> > > >>>>Not sure, if it is this patch ...
> > > >>>
> > > >>>Yeah, I don't think this is the patch causing the issue. AM335x-evm
> > > >>>boots fine for me. There are similar boot failures reported[1] on NVIDIA
> > > >>>platforms as well. Not sure if we are hitting the same issue. Ill did
> > > >>>more into this and update you guys.
> > > >>>
> > > >>>[1] https://www.mail-archive.com/u-boot at lists.denx.de/msg252698.html
> > > >>
> > > >>Time for using tbot and automated git bisect testcase ;-)
> > > >
> > > >How do you have the BBB configured such that you can recover it from a
> > > >bad U-Boot, automatically?  Thanks!
> > > 
> > > That;s exactly the reason, why I did not started a "git bisect", as this
> > > is not solved for the BBB in our lab. Wolfgang bought such a Airflash
> > > card, but we did not found time to try it.
> > 
> > Ah, the problem with BBB is that it wants to boot from eMMC, not SD,
> > unless the button is pressed.  It's possible, and I'd have to look at
> > the TRM and maybe the schematic, to see about changing the order, or
> > being able to remote boot it with a blank eMMC.
> 
>  BBB can directly boot from SD if you leave the eMMC blank, that's what
> I do on all my BBB.

I think I knew that, and forgot.  Thanks!  Time to order up more WiFi SD
cards I suspect...

-- 
Tom
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