[U-Boot] [PATCH] am33xx, spl, siemens: enable debug uart output again

[Tom Rini <trini@konsulko.com>]

On Thu, May 14, 2015 at 12:37:40PM +0200, Heiko Schocher wrote:
> Hello Tom,
> 
> Am 06.03.2015 08:24, schrieb Heiko Schocher:
> >Hello Tom,
> >
> >Am 05.03.2015 15:50, schrieb Tom Rini:
> >>On Thu, Mar 05, 2015 at 09:46:50AM +0100, Heiko Schocher wrote:
> >>>Hello Tom,
> >>>
> >>>Am 05.03.2015 07:22, schrieb Heiko Schocher:
> >>>>Hello Tom,
> >>>>
> >>>>Am 04.03.2015 17:40, schrieb Tom Rini:
> >>>>>On Wed, Mar 04, 2015 at 08:42:58AM +0100, Heiko Schocher wrote:
> >>>>>>Hello Tom,
> >>>>>>
> >>>>>>Am 02.03.2015 14:59, schrieb Tom Rini:
> >>>>>>>On Mon, Mar 02, 2015 at 07:56:41AM +0100, Heiko Schocher wrote:
> >>>>>>>>Hello Simon,
> >>>>>>>>
> >>>>>>>>Am 24.02.2015 14:31, schrieb Simon Glass:
> >>>>>>>>>Hi Heiko,
> >>>>>>>>>
> >>>>>>>>>On 23 February 2015 at 23:18, Heiko Schocher <hs@denx.de> wrote:
> >>>>>>>>>>a6b541b090: TI ARMv7: Don't use GD before crt0.S has set it
> >>>>>>>>>>
> >>>>>>>>>>moves the init of the debug uart at the very end of SPL code.
> >>>>>>>>>>Enable it for the siemens board earlier, as they print
> >>>>>>>>>>ddr settings ... all debug output before board_init_r()
> >>>>>>>>>>is here currently useless. Maybe we must rework this
> >>>>>>>>>>globally?
> >>>>>>>>>
> >>>>>>>>>Assuming we are talking about U-Boot proper, the DDR init should
> >>>>>>>>>happen in board_init_f(), specifically dram_init(). so I think this
> >>>>>>>>>code should be updated.
> >>>>>>>>>
> >>>>>>>>>If it is SPL, then DDR init should happen in SPL's board_init_f().
> >>>>>>>>
> >>>>>>>>It is in SPL...
> >>>>>>>>
> >>>>>>>>sdram_init() is called from:
> >>>>>>>>
> >>>>>>>>./arch/arm/cpu/armv7/am33xx/board.c from s_init() ...
> >>>>>>>>
> >>>>>>>>>I sent a series a few weeks ago (available at u-boot-dm branch
> >>>>>>>>>spl-working) related to this topic:
> >>>>>>>>>
> >>>>>>>>>http://patchwork.ozlabs.org/patch/438581/
> >>>>>>>>
> >>>>>>>>Ah ... Hmm... so "./arch/arm/cpu/armv7/am33xx/board.c" needs
> >>>>>>>>a rework, right?
> >>>>>>>>
> >>>>>>>>Is a simple rename s_init() -> board_init_f() correct?
> >>>>>>>
> >>>>>>>Right so, no, we can't just rename s_init to board_init_f.  This is what
> >>>>>>>I was talking about in the thread about the function Hans wants to add
> >>>>>>>to enable some bits in CP15 on sunxi, iirc.
> >>>>>>>
> >>>>>>>In short, armv7 has a different set of abstraction hooks than the
> >>>>>>>previous ARM cores (armv8 followed what we have for v7) and I'm not
> >>>>>>>convinced in the end that it really won us anything.  See
> >>>>>>>http://lists.denx.de/pipermail/u-boot/2015-January/202350.html
> >>>>>>>
> >>>>>>>For today you need to rework the Siemens code to print out the DDR
> >>>>>>>values (when desired) in spl_board_init() as we do not, or will not
> >>>>>>>shortly, have gd prior to board_init_f running.
> >>>>>>
> >>>>>>Hmm... first I thought, ok, no problem, move the output from the RAM
> >>>>>>parameters to spl_board_init() ... but thats only the half of the
> >>>>>>story ... They read the RAM parameters from an i2c eeprom, and if
> >>>>>>there are errors, they print this errors ... currently this does
> >>>>>>not work, and thats I think the more important case ... and I could
> >>>>>>not move this error printfs to somewhere, because if RAM is not
> >>>>>>working ... there is no later ...
> >>>>>>
> >>>>>>So I have to enable the console early ... maybe I missed something,
> >>>>>>but this worked fine in the past (and I think we should not break
> >>>>>>this, as this is an essential feature).
> >>>>>
> >>>>>OK, I missed something too.  I think this gets better now once I merge
> >>>>>Simon's SPL series as we do all of this from board_init_f() and the
> >>>>>siemens code should just work again.
> >>>>
> >>>>Yes, just saw your patch ;-)
> >>>>
> >>>>If they are in mainline (or do you have them somewhere in a git repo?),
> >>>>I test it again on the dxr2 board, thanks!
> >>>
> >>>If I am correct, all needed patches from you are in mainline, just
> >>>tried this on the dxr2 board ... but I still need:
> >>>
> >>>diff --git a/board/siemens/common/board.c b/board/siemens/common/board.c
> >>>index a39cbd0..8724604 100644
> >>>--- a/board/siemens/common/board.c
> >>>+++ b/board/siemens/common/board.c
> >>>@@ -40,6 +40,11 @@ void set_uart_mux_conf(void)
> >>>
> >>>  void set_mux_conf_regs(void)
> >>>  {
> >>>+       /* enable early the console */
> >>>+       gd->baudrate = CONFIG_BAUDRATE;
> >>>+       serial_init();
> >>>+       gd->have_console = 1;
> >>>+
> >>>         /* Initalize the board header */
> >>>         enable_i2c0_pin_mux();
> >>>         i2c_set_bus_num(0);
> >>>
> >>>to see the console output ...
> >>
> >>Yes, if you want console prior to spl_board_init() then you need to do
> >>that where you are.
> >>
> >
> >Ah, ok... so this patch is OK?
> 
> Just found this thread again, as I want to post updates for the am335x
> based siemens boards ... Is this patch [1] Ok, and can get applied?
> 
> Thanks!
> 
> bye,
> Heiko
> [1] Patchwork [U-Boot] am33xx, spl, siemens: enable debug uart output again
> https://patchwork.ozlabs.org/patch/446644/
> 
> Hups... found this patch in patchwork marked as RFC and Delegated
> to me ... ?

I'll look it over again then, thanks.

-- 
Tom
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