MacOs Mojave Kernel Panic

USB Cables PL2303-DB9
1

Hi, I’ve been using Plugable PL2303s for years on Macbook Pros without issues. However, after upgrading to Mojave, my Macbook has a kernel panic several times a week, and it might be caused by the Prolific driver, because it appears near the top of the report. Are there any updates for Mojave?

Thanks

2

Hi,

Thanks for reaching out to us, I am sorry to hear about the kernel panics.

We haven’t seen any reports of our USB to Serial adapter causing kernel panics in macOS Mojave, it is possibly a damaged driver. Diagnosing kernel panics can be difficult and time consuming, it often requires testing with and then without suspect hardware and software to determine if it affects the system stability. Our first step should be to remove and reinstall the USB serial driver to make sure it is in a good state.

The latest drivers for our PL2303-DB9 USB to RS232 serial adapter are available on our website here ( https://plugable.com/drivers/downloads ). The DMG file includes a PDF with instructions for removing the previous version of the drivers, I recommend following these instructions before reinstalling the drivers to help make sure nothing is left behind.

After the driver has been updated or reloaded I recommend restarting the system, please let me know if this helps to reduce or resolve the kernel panics and we can go from there.

Thank you,

Pat
Plugable Technology

3

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5

Hello,

This thread was automatically closed due to inactivity, but if you have any further questions please feel free to contact support@plugable.com and we’ll be happy to help.

Thanks,

Pat
Plugable Technologies

6

Unfortunately, I am still seeing this issue, almost every day, even after updating my macbook to 10.14.4:

Fri Apr 12 07:31:02 2019

*** Panic Report ***
panic(cpu 0 caller 0xffffff800a2dd16d): Kernel trap at 0xffffff8009f93333, type 14=page fault, registers:
…

Mac OS version:
18E226

Kernel version:
Darwin Kernel Version 18.5.0: Mon Mar 11 20:40:32 PDT 2019; root:xnu-4903.251.3~3/RELEASE_X86_64
…
System model name: MacBookPro11,4 (Mac-06F11FD93F0323C5)

System uptime in nanoseconds: 38117564408763
last loaded kext at 38074703102142: com.apple.iokit.IOBluetoothUSBDFU 6.0.11f4 (addr 0xffffff7f8c77a000, size 12288)
last unloaded kext at 21821120368696: com.apple.driver.AppleHDAHardwareConfigDriver 282.54 (addr 0xffffff7f8c4bf000, size 8192)
loaded kexts:
com.prolific.driver.PL2303 1.6.0

7

Hi,

I am sorry the system is still crashing, unfortunately the log file segment does not point to a specific cause.

Is it possible to send the entire crash log to my email ‘support@plugable.com’ with the subject line ‘Ticket #268104 - Attention Pat’? I can dig into the log file to see if it has any relevant information about the failure.

Does the system enter the panic state only when the serial adapter is connected and active or just when connected, or even if the adapter is disconnected?

Thank you,

Pat
Plugable Technology

8

Hi Julian,

Thank you for emailing the log file, I will be digging into this to see if I can find anything that can help! Also, thank you for the additional details that this error comes up when waking from sleep.

While I am digging into this log and consulting our Mac expert, would it be possible to test the system overnight after removing the prolific driver ( per the instructions in the PDF file in the Prolific driver .dmg file ) and disconnecting the serial adapter. Then closing the lid like normal to see if the error is still being produced at startup?

I will post an update when I have had a chance to run this by our Mac expert.

Thank you,

Pat
Plugable Technology

9

Hi Julian,

I ran this log file by our Mac expert, and it is telling us the system is encountering an unspecified error. Based on the state of the system when this is crashing it would appear to be trying to load drivers for hardware after waking from sleep.

This can potentially be caused by a software glitch causing the system to load the wrong driver for a specific piece of hardware, for example loading a generic driver when a more specific driver is available.

Based on this we can reset the NVRAM and PRAM ( following the instructions from Apple here: https://support.apple.com/en-us/HT204063 ) and then we can put the system to sleep and wake to see if the errors are continuing before removing the Prolific Serial Drivers per my previous post.

To reset the NVRAM and PRAM:

  1. Shut down your MacBook ( Apple → Shutdown )
  2. Press the power button to turn it on and immediately press and hold these four keys together: Option, Command, P, and R.
  3. After about 20 seconds you can release the keys, during this time MacBook might appear to restart
    After booting back to the operating system please double check the serial adapter is detected and working correctly with your serial device, then close the lid to put the system to sleep. After a couple of minutes open the lid to wake the system.

Please let me know if the kernel panic occurs, if not we can let it go over night and check again in the morning.

Thank you,

Pat
Plugable Technology