SD Overclock = Kernel Panic

navi87

Pi Model 2b+
Power Supply used: Official Pi
RetroPie Version Used: 4.5
Built From: Pre made SD Image on RetroPie website 4.5
USB Devices connected: Bluteooth Dongle
Controller used: PS4 via Blutetooth
Error messages received: "kernel panic-not syncing: vfs: unable to mount root fs on unknown-block(179,2)"
How to replicate the problem:
Inserting "dtparam=sd_overclock=100" into config.txt

Ive been trying to overclock my SD card (32gb Samsung Evo Plus) but after editing the config.txt I get the kernel panic message.

I did try to fix this by changing the cmdline.txt file and editing the root directory as suggested by JonnyKesh on this thread:
https://retropie.org.uk/forum/topic/10935/retropie-kernel-panic-not-syncing-vfs-unable-to-mount-root-fs-on-unknown-block-179-2/10
But that just change the error message from "unknown-block(179,2)" to "unknown-block(179,6)"

Once I remove the overclock line in the config.txt I am able to boot , the SD card is fine.

Is this overclock even possible on the Pi 2b+? I have seen guides which mentions it is for all the Pi's but all the threads I found on this subject seem to be Pi 3 users.

Help?

Regards,

Navi

dankcushions

@navi87
try a lower overclock, like 83?

navi87

Yeah I tried that out too, I thought I was pushing it too hard as well but I got the same result.

backstander

@navi87
Try this instead:
dtoverlay=sdhost,overclock_50=100

Cesarpuig

@navi87

I had a problem similar to yours on a Raspberry Pi 3B. I solved it by decreasing the overclock I had done to the CPU, GPU and RAM. Not only did I have problems with the SD Overclock, but I also had some type of return castle of Wolfesteim game.

With this overclock I had the same problem as you:

#uncomment to overclock the arm. 700 MHz is the default.
arm_freq=1400
over_voltage=6
gpu_freq=550
core_freq=550
sdram_freq=550
sdram_schmoo=0x02000020
over_voltage_sdram_p=6
over_voltage_sdram_i=4
over_voltage_sdram_c=4

#uncomment to increased the sdcard reader speed (No default)
dtparam=sd_overclock=100

And so solve it:

#uncomment to overclock the arm. 700 MHz is the default.
arm_freq=1400
over_voltage=6
gpu_freq=525
core_freq=525
sdram_freq=550
sdram_schmoo=0x02000020
over_voltage_sdram_p=6
over_voltage_sdram_i=4
over_voltage_sdram_c=4

#uncomment to increased the sdcard reader speed (No default)
dtparam=sd_overclock=100

navi87

@backstander I tried that didnt work as well. I have a feeling my SD card just isnt upto scratch.

I got myself a Pi 4b now with a 64GB micro sd card, the "dtparam=sd_overclock=100" and it works fine. Consider this case closed, cheers for all the input though guys :)