Percy28
Posts: 9
Joined: Tue Jul 08, 2014 7:45 am

Prolific PL2303 Driver no longer initializes

Tue Jul 08, 2014 7:58 am

Hello experts - I hope this is the right place to post my problem.

I have had a Pi Rev B for 3 months and it has been gathering and processing data from my CurrentCost home energy monitor and feeding my own hosted (on the PI) EmonCMS energy management system.

The Pi stopped responding, and after some investigation found that the SD card was at fault, and preventing it from booting.

I created an new SD card, and it now boots fine. I read read on a forum that having the latest firmware may correct some known SD card issues on the Pi so I carried out a firmware update (rpi-update).

Now I have access to my EmonCMS server on the Pi - all good. Trying to start up my code that grabs the data via RS232 port on the CurrentCost Envir, (a small perl based script) I get an error at ttyUSB0 is not found.

# lsusb -v reports (see Bus 001 Device 004 - and note DeviceStatus 0x0000):
Bus 001 Device 002: ID 0424:9514 Standard Microsystems Corp.
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.00
bDeviceClass 9 Hub
bDeviceSubClass 0 Unused
bDeviceProtocol 2 TT per port
bMaxPacketSize0 64
idVendor 0x0424 Standard Microsystems Corp.
idProduct 0x9514
bcdDevice 2.00
iManufacturer 0
iProduct 0
iSerial 0
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 41
bNumInterfaces 1
bConfigurationValue 1
iConfiguration 0
bmAttributes 0xe0
Self Powered
Remote Wakeup
MaxPower 2mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 1
bInterfaceClass 9 Hub
bInterfaceSubClass 0 Unused
bInterfaceProtocol 1 Single TT
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x0001 1x 1 bytes
bInterval 12
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 1
bNumEndpoints 1
bInterfaceClass 9 Hub
bInterfaceSubClass 0 Unused
bInterfaceProtocol 2 TT per port
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x0001 1x 1 bytes
bInterval 12
Hub Descriptor:
bLength 9
bDescriptorType 41
nNbrPorts 5
wHubCharacteristic 0x000d
Per-port power switching
Compound device
Per-port overcurrent protection
TT think time 8 FS bits
bPwrOn2PwrGood 50 * 2 milli seconds
bHubContrCurrent 1 milli Ampere
DeviceRemovable 0x02
PortPwrCtrlMask 0xff
Hub Port Status:
Port 1: 0000.0503 highspeed power enable connect
Port 2: 0000.0103 power enable connect
Port 3: 0000.0503 highspeed power enable connect
Port 4: 0000.0100 power
Port 5: 0000.0100 power
Device Qualifier (for other device speed):
bLength 10
bDescriptorType 6
bcdUSB 2.00
bDeviceClass 9 Hub
bDeviceSubClass 0 Unused
bDeviceProtocol 0 Full speed (or root) hub
bMaxPacketSize0 64
bNumConfigurations 1
Device Status: 0x0001
Self Powered

Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.00
bDeviceClass 9 Hub
bDeviceSubClass 0 Unused
bDeviceProtocol 1 Single TT
bMaxPacketSize0 64
idVendor 0x1d6b Linux Foundation
idProduct 0x0002 2.0 root hub
bcdDevice 3.06
iManufacturer 3 Linux 3.6.11+ dwc_otg_hcd
iProduct 2 DWC OTG Controller
iSerial 1 bcm2708_usb
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 25
bNumInterfaces 1
bConfigurationValue 1
iConfiguration 0
bmAttributes 0xe0
Self Powered
Remote Wakeup
MaxPower 0mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 1
bInterfaceClass 9 Hub
bInterfaceSubClass 0 Unused
bInterfaceProtocol 0 Full speed (or root) hub
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x0004 1x 4 bytes
bInterval 12
Hub Descriptor:
bLength 9
bDescriptorType 41
nNbrPorts 1
wHubCharacteristic 0x0008
Ganged power switching
Per-port overcurrent protection
TT think time 8 FS bits
bPwrOn2PwrGood 1 * 2 milli seconds
bHubContrCurrent 0 milli Ampere
DeviceRemovable 0x00
PortPwrCtrlMask 0xff
Hub Port Status:
Port 1: 0000.0503 highspeed power enable connect
Device Status: 0x0001
Self Powered

Bus 001 Device 003: ID 0424:ec00 Standard Microsystems Corp.
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.00
bDeviceClass 255 Vendor Specific Class
bDeviceSubClass 0
bDeviceProtocol 1
bMaxPacketSize0 64
idVendor 0x0424 Standard Microsystems Corp.
idProduct 0xec00
bcdDevice 2.00
iManufacturer 0
iProduct 0
iSerial 0
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 39
bNumInterfaces 1
bConfigurationValue 1
iConfiguration 0
bmAttributes 0xe0
Self Powered
Remote Wakeup
MaxPower 2mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 3
bInterfaceClass 255 Vendor Specific Class
bInterfaceSubClass 0
bInterfaceProtocol 255
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x02 EP 2 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x83 EP 3 IN
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x0010 1x 16 bytes
bInterval 4
Device Qualifier (for other device speed):
bLength 10
bDescriptorType 6
bcdUSB 2.00
bDeviceClass 255 Vendor Specific Class
bDeviceSubClass 0
bDeviceProtocol 1
bMaxPacketSize0 64
bNumConfigurations 1
Device Status: 0x0001
Self Powered

Bus 001 Device 004: ID 067b:2303 Prolific Technology, Inc. PL2303 Serial Port
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 1.10
bDeviceClass 0 (Defined at Interface level)
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 64
idVendor 0x067b Prolific Technology, Inc.
idProduct 0x2303 PL2303 Serial Port
bcdDevice 3.00
iManufacturer 1 Prolific Technology Inc.
iProduct 2 USB-Serial Controller
iSerial 0
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 39
bNumInterfaces 1
bConfigurationValue 1
iConfiguration 0
bmAttributes 0x80
(Bus Powered)
MaxPower 100mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 3
bInterfaceClass 255 Vendor Specific Class
bInterfaceSubClass 0
bInterfaceProtocol 0
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x000a 1x 10 bytes
bInterval 1
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x02 EP 2 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0040 1x 64 bytes
bInterval 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x83 EP 3 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0040 1x 64 bytes
bInterval 0
Device Status: 0x0000
(Bus Powered)

Bus 001 Device 005: ID 152d:2338 JMicron Technology Corp. / JMicron USA Technology Corp. JM20337 Hi-Speed USB to SATA & PATA Combo Bridge
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.00
bDeviceClass 0 (Defined at Interface level)
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 64
idVendor 0x152d JMicron Technology Corp. / JMicron USA Technology Corp.
idProduct 0x2338 JM20337 Hi-Speed USB to SATA & PATA Combo Bridge
bcdDevice 1.00
iManufacturer 1 JMicron
iProduct 2 USB to ATA/ATAPI bridge
iSerial 5 113081918014
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 32
bNumInterfaces 1
bConfigurationValue 1
iConfiguration 4 USB Mass Storage
bmAttributes 0xc0
Self Powered
MaxPower 2mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 2
bInterfaceClass 8 Mass Storage
bInterfaceSubClass 6 SCSI
bInterfaceProtocol 80 Bulk-Only
iInterface 6 MSC Bulk-Only Transfer
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x02 EP 2 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Device Qualifier (for other device speed):
bLength 10
bDescriptorType 6
bcdUSB 2.00
bDeviceClass 0 (Defined at Interface level)
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 64
bNumConfigurations 1
Device Status: 0x0001
Self Powered

Checking that a driver still exists I see:
# find /lib/modules -name *2303*
returns:
/lib/modules/3.12.24+/kernel/drivers/usb/serial/pl2303.ko
/lib/modules/3.10.25+/kernel/drivers/usb/serial/pl2303.ko

If I try to install the module I get an error:
# sudo insmod /lib/modules/3.10.25+/kernel/drivers/usb/serial/pl2303.ko
Error: could not insert module /lib/modules/3.10.25+/kernel/drivers/usb/serial/pl2303.ko: Invalid module format

My limited Pi knowledge is at an end, and I'm now going around in circles on my Google based education. Can someone please help me get back up and running?

Thanks in advance.

rotwang
Posts: 243
Joined: Sat Dec 07, 2013 1:12 pm

Re: Prolific PL2303 Driver no longer initializes

Tue Jul 08, 2014 4:48 pm

I know this is going to sound like a stupid question, but from your post you have two sets of kernel modules, have you checked that the module you are trying to load is the same version as the running kernel ("uname -a" should give you the running version)

Percy28
Posts: 9
Joined: Tue Jul 08, 2014 7:45 am

Re: Prolific PL2303 Driver no longer initializes

Wed Jul 09, 2014 8:41 pm

Thanks - appreciate your input.

I checked and have this:
$ uname -a
Linux emoncms 3.6.11+ #538 PREEMPT Fri Aug 30 20:42:08 BST 2013 armv6l GNU/Linux

User avatar
joan
Posts: 14361
Joined: Thu Jul 05, 2012 5:09 pm
Location: UK

Re: Prolific PL2303 Driver no longer initializes

Wed Jul 09, 2014 8:53 pm

Percy28 wrote:Thanks - appreciate your input.

I checked and have this:
$ uname -a
Linux emoncms 3.6.11+ #538 PREEMPT Fri Aug 30 20:42:08 BST 2013 armv6l GNU/Linux
You need to get the 3.6.11 modules. Modules are built against a specific kernel version.

Percy28
Posts: 9
Joined: Tue Jul 08, 2014 7:45 am

Re: Prolific PL2303 Driver no longer initializes

Wed Jul 09, 2014 8:58 pm

Ah! Is there a straightforward way to get the correct modules on my Pi?

Thank you again

User avatar
joan
Posts: 14361
Joined: Thu Jul 05, 2012 5:09 pm
Location: UK

Re: Prolific PL2303 Driver no longer initializes

Wed Jul 09, 2014 9:02 pm

Percy28 wrote:Ah! Is there a straightforward way to get the correct modules on my Pi?

Thank you again
I don't understand how your system managed to get incompatible modules.

I suggest you do a

sudo rpi-update

That should update the kernel and modules to 3.12.23+ #692.

Percy28
Posts: 9
Joined: Tue Jul 08, 2014 7:45 am

Re: Prolific PL2303 Driver no longer initializes

Wed Jul 09, 2014 9:05 pm

Hmm..
pi# sudo rpi-update
*** Raspberry Pi firmware updater by Hexxeh, enhanced by AndrewS and Dom
*** Performing self-update
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 7037 100 7037 0 0 19863 0 --:--:-- --:--:-- --:--:-- 28375
*** Relaunching after update
*** Raspberry Pi firmware updater by Hexxeh, enhanced by AndrewS and Dom
*** Your firmware is already up to date

Percy28
Posts: 9
Joined: Tue Jul 08, 2014 7:45 am

Re: Prolific PL2303 Driver no longer initializes

Wed Jul 09, 2014 9:07 pm

Thanks...

Hmm..
pi# sudo rpi-update
*** Raspberry Pi firmware updater by Hexxeh, enhanced by AndrewS and Dom
*** Performing self-update
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 7037 100 7037 0 0 19863 0 --:--:-- --:--:-- --:--:-- 28375
*** Relaunching after update
*** Raspberry Pi firmware updater by Hexxeh, enhanced by AndrewS and Dom
*** Your firmware is already up to date

Is it possible to get the module by name? (Sorry I'm no Pi/Linux expert - as you can tell :))

User avatar
joan
Posts: 14361
Joined: Thu Jul 05, 2012 5:09 pm
Location: UK

Re: Prolific PL2303 Driver no longer initializes

Wed Jul 09, 2014 9:13 pm

I have no idea what is happening with your Pi.

This isn't a Linux problem per se, rpi-update is specific to the Pi.

You'll have to wait for someone who understands why 3.6.11 can be up to date.

MrEngman
Posts: 3856
Joined: Fri Feb 03, 2012 2:17 pm
Location: Southampton, UK

Re: Prolific PL2303 Driver no longer initializes

Wed Jul 09, 2014 9:35 pm

When rpi-update runs it looks at a file in the /boot sector to determine if it is up to date or not. If the file contains an old value or the file is not there then rpi-update should run and install the latest firmware. 3.6.11+ should be updated using rpi-update but if you've copied any files to your /boot sector for any reason then maybe an up to date copy of /boot/.firmware_revision has been copied there unintentionally.

If /boot/.firmware_revision exists you can check it's value with command

Code: Select all

cat /boot/.firmware_revision
and verify it against the list of firmware commits at https://github.com/Hexxeh/rpi-firmware/commits/master and see if it matches the latest value which would explain why rpi-update insists your firmware is up to date.

You can check if the file /boot/.firmware_revision exists with

Code: Select all

ls -A /boot
and see if it is listed and delete it if it does.

Code: Select all

sudo rm /boot/.firmware_revision

MrEngman
Simplicity is a prerequisite for reliability. Edsger W. Dijkstra

Please post ALL technical questions on the forum. Please Do Not send private messages.

Percy28
Posts: 9
Joined: Tue Jul 08, 2014 7:45 am

Re: Prolific PL2303 Driver no longer initializes

Wed Jul 09, 2014 9:44 pm

Thank you - really appreciate your help.

The cat command returned:
d9eb023ba98317d81fc53a3f9d6752b127a8dbbf

Now I'm quite confuse because that code matches kernel: Bump to 3.12.24 at the link you provide (which appears to be the latest version). I understood I was on version 3.6.11+ from the uname -a command.

So which is correct the cat key or the uname value?

(Feeling rather ignorant... so sorry of these are not related)

User avatar
joan
Posts: 14361
Joined: Thu Jul 05, 2012 5:09 pm
Location: UK

Re: Prolific PL2303 Driver no longer initializes

Wed Jul 09, 2014 9:52 pm

Who knows.

Delete the file and do an rpi-update. Then reboot and check uname again.

Percy28
Posts: 9
Joined: Tue Jul 08, 2014 7:45 am

Re: Prolific PL2303 Driver no longer initializes

Wed Jul 09, 2014 10:03 pm

joan wrote:Who knows.

Delete the file and do an rpi-update. Then reboot and check uname again.
I deleted the file. Runnig rpi-update returns:
*** Raspberry Pi firmware updater by Hexxeh, enhanced by AndrewS and Dom
*** Performing self-update
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 7037 100 7037 0 0 15644 0 --:--:-- --:--:-- --:--:-- 33669
*** Relaunching after update
*** Raspberry Pi firmware updater by Hexxeh, enhanced by AndrewS and Dom
*** We're running for the first time
*** Backing up files (this will take a few minutes)
*** Backing up firmware
*** Backing up modules 3.6.11+
cp: cannot stat `//lib/modules/3.6.11+': No such file or directory

The process refuses to run

User avatar
joan
Posts: 14361
Joined: Thu Jul 05, 2012 5:09 pm
Location: UK

Re: Prolific PL2303 Driver no longer initializes

Wed Jul 09, 2014 10:10 pm

Personally I'd have no faith in the consistency of the contents of that SD card. I'd wipe it and start again from a recent download image.

MrEngman
Posts: 3856
Joined: Fri Feb 03, 2012 2:17 pm
Location: Southampton, UK

Re: Prolific PL2303 Driver no longer initializes

Wed Jul 09, 2014 10:40 pm

Percy28 wrote:Thank you - really appreciate your help.

The cat command returned:
d9eb023ba98317d81fc53a3f9d6752b127a8dbbf

Now I'm quite confuse because that code matches kernel: Bump to 3.12.24 at the link you provide (which appears to be the latest version). I understood I was on version 3.6.11+ from the uname -a command.

So which is correct the cat key or the uname value?

(Feeling rather ignorant... so sorry of these are not related)
Glad to be able to provide some help.

You can check what version is loaded using command

Code: Select all

ls /lib/modules
which will probably show 3.12.24+ but whether it will show 3.6.11+, it probably won't.

I'm not completely sure where uname -a gets it data from but if the kernel you have loaded in the /boot directory and so are running is 3.6.11+ then that may explain why.

If your SD card had 3.12.24+ installed and then you copied 3.6.11+ files to the boot directory this could explain your problems and what you are seeing now.


MrEngman
Simplicity is a prerequisite for reliability. Edsger W. Dijkstra

Please post ALL technical questions on the forum. Please Do Not send private messages.

MrEngman
Posts: 3856
Joined: Fri Feb 03, 2012 2:17 pm
Location: Southampton, UK

Re: Prolific PL2303 Driver no longer initializes

Wed Jul 09, 2014 11:34 pm

Just a thought. If the directory /lib/modules/3.6.11+ doesn't exist you could create it, eg

Code: Select all

sudo mkdir /lib/modules/3.6.11+
and then see if rpi-update will run. Mind you it may then start complaining other directories are missing. Still maybe worth a try.



MrEngman
Simplicity is a prerequisite for reliability. Edsger W. Dijkstra

Please post ALL technical questions on the forum. Please Do Not send private messages.

Percy28
Posts: 9
Joined: Tue Jul 08, 2014 7:45 am

Re: Prolific PL2303 Driver no longer initializes

Fri Jul 11, 2014 2:27 pm

Thank you MrEngman

You were correct the directory did not exist, so I created it. Update completed successfully. However I still cannot initialise the PL2303 and access my CurrentCost envir via ttyUSB0 in perl.

I think the issue maybe related to the fact (that I haven't previously mentioned!) I use the EmonCMS SD image to boot with HDD - which gives me a 1TB HDD to register all of my energy consumption and other events.

So I'm guessing there are some files updated on the SD, but not sure if the required files are updated on the HDD - maybe this is why it still thinks I'm on an older version?

I'm a bit stuck now - all of my history and configuration is on the HDD - I don't want to reinitialise that. I've tried re-flashing the SD card with the original boot image.

Is there any logic in my assumption? If so - are there parameters for rpi-update that specify I want to update SD and HDD?

Hope this makes sense?

bdl
Posts: 2
Joined: Sat Jul 12, 2014 9:52 am

Re: Prolific PL2303 Driver no longer initializes

Sat Jul 12, 2014 10:36 am

G'Day Percy,
As you may already know, the root issue with your pi seems to be that the installed modules version doesn't match your running kernel. The kernel can't find the USB serial module for the current kernel version, and thus the /dev/ttyUSB0 won't be available.

Aside on modules: in order to support a bazillion hardware variations, drivers/etc for most non-core hardware - e.g. USB serial adapters - are provided via a 'kernel module'. A module is a piece of code that gets loaded into the kernel after the system has booted, either manually (via /etc/modules, or modprobe/insmod) or automatically (via udev). Modules are very particular to a specific kernel version, and are stored in /lib/modules/, in a sub-directory named after the kernel version. In normal circumstances, there will be a directory in /lib/modules that matches your current kernel version (uname -r). e.g. for kernel 3.12.24+, modules are in /lib/modules/3.12.24+/.

i.e. the current modules for your kernel are:
# ls /lib/modules/$(uname -r)/

e.g.
# find /lib/modules/$(uname -r)/ -name pl2303.ko
/lib/modules/3.12.24+/kernel/drivers/usb/serial/pl2303.ko

I don't know how your system got out of whack. On a normal Debian system you install the linux-image-* package which includes the matched kernel and modules. On a pi you normally use rpi-update to manage the kernel, modules and chipset firmware. I've seen the same 'missing modules' error on rpi-update-ing my pi, no idea how it got in that state, but a reboot to the new kernel and retry of rpi-update fixed it. (I wonder if what happened was an update from kernel A to B where I didn't reboot, then another update from B to C but the running kernel was still on A).

In any event when you update your pi you have to reboot to switch to the new kernel, so if rpi-update barfs on any kernel-module mismatch, reboot and try again.

Also, there are various options for rpi-update, including to skip the backup or force an update: see here for details: https://github.com/Hexxeh/rpi-update
e.g. sudo SKIP_BACKUP=1 rpi-update

Note: you DO NOT have to erase or touch your external drive. Unless you've done something quite unusual, any external drives won't have any effect on the kernel or available modules - these are always on the root filesystem (SD card).

Good luck!

Ben

Percy28
Posts: 9
Joined: Tue Jul 08, 2014 7:45 am

SOLVED Prolific PL2303 Driver no longer initializes

Sat Jul 12, 2014 8:50 pm

Thanks Ben for your suggestions. It was a helpful pointer.

I have managed to fix my problem (Hurray!). I found the solution here: http://openenergymonitor.org/emon/node/3688.

To be honest I don't fully understand the setup - but It would appear that the EmonCMS has a boot image on SD and HDD. The process at the link provides a download which I used to reflash my SD card, and clean up the HDD as described. So I'm now able to use rpi-update as designed.

Thanks for all of you time and insight - its very helpful, and encouraging to know that there are folks like you out there to offer a helping hand.

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