* rk3399: uart2 crippled signal on tx @115200
@ 2020-06-18 10:10 Chris Ruehl
2020-06-26 0:01 ` Chris Ruehl
0 siblings, 1 reply; 2+ messages in thread
From: Chris Ruehl @ 2020-06-18 10:10 UTC (permalink / raw)
To: linux-arm, linux-serial; +Cc: Jack Lo
Hi,
I run into a strange thing on our customized RK3399-LPDDR4 using the
UART2 @115200 the
console spits bad charters. Checking the signal at the TX explains the
reason, the rising edge
is very slow, (we checked with the scope).
Set the GPIO4_C4 to pcfg_pull_up_20am not working.
Kernel: 5.4.40-rt
Uboot: 2020-4
The strange observation:
U-boot TPL boot , return to Boot-rom and the 1st
lines from SPL (show uboot version) have a sharp rising edge as expected.
Anyone? I don't know anymore.
Regards
Chris
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: rk3399: uart2 crippled signal on tx @115200
2020-06-18 10:10 rk3399: uart2 crippled signal on tx @115200 Chris Ruehl
@ 2020-06-26 0:01 ` Chris Ruehl
0 siblings, 0 replies; 2+ messages in thread
From: Chris Ruehl @ 2020-06-26 0:01 UTC (permalink / raw)
To: linux-arm, linux-serial; +Cc: Jack Lo
On 18/6/2020 6:10 pm, Chris Ruehl wrote:
> Hi,
>
> I run into a strange thing on our customized RK3399-LPDDR4 using the UART2
> @115200 the
> console spits bad charters. Checking the signal at the TX explains the reason,
> the rising edge
> is very slow, (we checked with the scope).
> Set the GPIO4_C4 to pcfg_pull_up_20am not working.
>
> Kernel: 5.4.40-rt
> Uboot: 2020-4
>
> The strange observation:
> U-boot TPL boot , return to Boot-rom and the 1st
> lines from SPL (show uboot version) have a sharp rising edge as expected.
>
> Anyone? I don't know anymore.
>
> Regards
> Chris
Solved. rk3399 io_domain problem supply 3.3v for all rails.
one was configured for 1.8v and that confused the rk808 had
reverence voltage on the uart block 2.5v not 1.5v.
all good now.
Chris
^ permalink raw reply [flat|nested] 2+ messages in thread
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