Re: [PATCH v2] clk: bcm2835: Do not use prediv with bcm2711's PLLs

From: Nathan Chancellor
Date: Thu Jul 30 2020 - 22:05:59 EST


On Thu, Jul 30, 2020 at 08:26:19PM +0200, Nicolas Saenz Julienne wrote:
> Contrary to previous SoCs, bcm2711 doesn't have a prescaler in the PLL
> feedback loop. Bypass it by zeroing fb_prediv_mask when running on
> bcm2711.
>
> Note that, since the prediv configuration bits were re-purposed, this
> was triggering miscalculations on all clocks hanging from the VPU clock,
> notably the aux UART, making its output unintelligible.
>
> Fixes: 42de9ad400af ("clk: bcm2835: Add BCM2711_CLOCK_EMMC2 support")
> Reported-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
> Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@xxxxxxx>

I updated to the latest version of the firmware
(668419cb9876474053574b2b1dc20ca996e14cc8) and my serial console
works :) thank you for the quick fix!

Tested-by: Nathan Chancellor <natechancellor@xxxxxxxxx>