[PATCH master] Revert "ARM: beaglebone: init MPU speed to 800Mhz"

[Ahmad Fatoum]

Hello Marc,

On 03.12.21 19:51, Ahmad Fatoum wrote:
> Commit 130c7d6715e9 ("ARM: beaglebone: init MPU speed to 800Mhz") causes
> warm reboot from within Linux v5.14.0 to no longer succeed.
> barebox MLO is entered, but hangs. Reset from within barebox is
> unaffected.
> This can be reproduced using DistroKit 949c5ef2b9a6 ("v7a: barebox:
> version bump v2021.08.0 → v2021.11.0") on a Beaglebone Black.
> Until that's figured out, revert the commit; functional reboot is more
> important than the quicker boot up.
> 
> This reverts commit 130c7d6715e932a1e0b3e026fea97f700ab33ea9.

I send a revert, so barebox v2021.12.0 can ship with the regression fixed.
Would be great if you could take a look to see what needs to be done
differently to reinstate the clock frequency increase.

Cheers,
Ahmad

> 
> Fixes: 130c7d6715e9 ("ARM: beaglebone: init MPU speed to 800Mhz")
> Reported-by: arwie # IRC
> Cc: Marc Reilly <marc at cpdesign.com.au>
> Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
> ---
>  arch/arm/boards/beaglebone/lowlevel.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/arm/boards/beaglebone/lowlevel.c b/arch/arm/boards/beaglebone/lowlevel.c
> index 31211448f5e8..91d143e4150b 100644
> --- a/arch/arm/boards/beaglebone/lowlevel.c
> +++ b/arch/arm/boards/beaglebone/lowlevel.c
> @@ -126,7 +126,7 @@ static noinline int beaglebone_sram_init(void)
>  
>  	/* Setup the PLLs and the clocks for the peripherals */
>  	if (is_beaglebone_black()) {
> -		am33xx_pll_init(MPUPLL_M_800, DDRPLL_M_400);
> +		am33xx_pll_init(MPUPLL_M_500, DDRPLL_M_400);
>  		am335x_sdram_init(0x18B, &ddr3_cmd_ctrl, &ddr3_regs,
>  				&ddr3_data);
>  	} else {
> 


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