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| author | Koen Vandeputte <koen.vandeputte@ncentric.com> | 2021-06-28 10:57:21 +0200 |
|---|---|---|
| committer | Koen Vandeputte <koen.vandeputte@ncentric.com> | 2021-07-09 17:14:01 +0200 |
| commit | 0ad49d368b33de12a20ee5c9adcf0273aac891fa (patch) | |
| tree | 3a7cecd30fc9fcc98547895255a1531547d66670 /target/linux | |
| parent | ffa943f0b913f0f26018df7eebddab2f0a1daada (diff) | |
| download | upstream-0ad49d368b33de12a20ee5c9adcf0273aac891fa.tar.gz upstream-0ad49d368b33de12a20ee5c9adcf0273aac891fa.tar.bz2 upstream-0ad49d368b33de12a20ee5c9adcf0273aac891fa.zip | |
ath79: mikrotik: fix beeper phantom noise on RB912
Analysis done by Denis Kalashnikov:
It seems that some ROS versions on some routerboard models have this bug:
after silence boot (no output to uart, no beeps) beeper clicks when wireless traffic is.
https://forum.mikrotik.com/viewtopic.php?f=3&t=92269
https://forum.mikrotik.com/viewtopic.php?t=63399
From these links:
1)
Hello, I have RB951G-2HnD and I noticed strange thing
when I loaded the device with some wireless traffic it
produced strange sound - like hissing, fizzing etc.
2)
Same problem still on 6.33, with silent boot enabled
I hear buzzing noise on wireless load.
3)
The sound is fixed in v5.19, it was a bug that caused beeper to make clicks.
It also got fixed in RouterOS:
* What's new in 5.19 (2012-Jul-16 10:51):
fix ticking sound on RB411UAHL;
* What's new in 6.38.3 (2017-Feb-07 09:52):
rb3011 - fixed noise from buzzer after silent boot;
I've checked with an oscilloscope that:
* When on the ssr beeper pin is 0,
on the beeper itself is 1 (~5V),
and when on the ssr beeper pin is 1,
on the beeper is 0
The beeper doesn't consume power,
so 1 should be a default/idle value for the ssr beeper pin).
* When there is wireless traffic (ping packets)
in the background and the beeper clicks, I see
pulses on the beeper itself,
but no pulses on the ssr beeper pin (Q5 pin of 74hc595).
When I manually toggle the ssr beeper pin I see pulses on both.
So, it is likely that the phantom beeper clicks are caused by the EMI.
Suggested-by: Denis Kalashnikov <denis281089@gmail.com>
Reviewed-by: Sergey Ryazanov <ryazanov.s.a@gmail.com>
Signed-off-by: Koen Vandeputte <koen.vandeputte@ncentric.com>
(cherry picked from commit a58bcc9e673db3c6aa39f2089d216d51c8356418)
Diffstat (limited to 'target/linux')
| -rw-r--r-- | target/linux/ath79/dts/ar9342_mikrotik_routerboard-912uag-2hpnd.dts | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/target/linux/ath79/dts/ar9342_mikrotik_routerboard-912uag-2hpnd.dts b/target/linux/ath79/dts/ar9342_mikrotik_routerboard-912uag-2hpnd.dts index cc5553acda..ee2c12b4e0 100644 --- a/target/linux/ath79/dts/ar9342_mikrotik_routerboard-912uag-2hpnd.dts +++ b/target/linux/ath79/dts/ar9342_mikrotik_routerboard-912uag-2hpnd.dts @@ -107,6 +107,12 @@ gpio-export { compatible = "gpio-export"; + beeper { + gpio-export,name = "beeper"; + gpio-export,output = <1>; /* Must be 1 to avoid EMI induced clicking noise */ + gpios = <&ssr 5 GPIO_ACTIVE_HIGH>; + }; + usb_power { gpio-export,name = "power-usb"; gpio-export,output = <1>; |