FTDI spontanteous disconnect/reconnect

FTDI spontanteous disconnect/reconnect

[Sven Lahr]

Hi there

I work for a company that produces a system that contains a device with an FTDI 232R chip, as well as a Linux (Debian) computer that the device is attached to.
We often get reports from our customers that the device is disconnected, and then reconnected shortly thereafter. I have searched the web, and apparently quite a lot of people experience this when they use the Linux driver.
I wonder if there is any plan to fix this. From what I can tell the Linux driver hasn't been updated in 5 years.

Below I have pasted the relevant part of my kernel log.


Best regards
Sven Lähr, Biotage AB, Sweden

Feb 27 19:45:44 kernel: [  936.368366] ftdi_sio ttyUSB0: FTDI USB Serial Device converter now disconnected from ttyUSB0
Feb 27 19:45:44 kernel: [  936.368379] ftdi_sio 4-2:1.0: device disconnected
Feb 27 19:45:44 kernel: [  936.608030] usb 4-2: new full-speed USB device number 3 using uhci_hcd
Feb 27 19:45:44 kernel: [  936.806105] usb 4-2: New USB device found, idVendor=0403, idProduct=6001
Feb 27 19:45:44 kernel: [  936.806110] usb 4-2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
Feb 27 19:45:44 kernel: [  936.806115] usb 4-2: Product: FT232R USB UART
Feb 27 19:45:44 kernel: [  936.806118] usb 4-2: Manufacturer: FTDI
Feb 27 19:45:44 kernel: [  936.806121] usb 4-2: SerialNumber: A602WS4T
Feb 27 19:45:44 kernel: [  936.814150] ftdi_sio 4-2:1.0: FTDI USB Serial Device converter detected
Feb 27 19:45:44 kernel: [  936.814195] usb 4-2: Detected FT232RL
Feb 27 19:45:44 kernel: [  936.814198] usb 4-2: Number of endpoints 2
Feb 27 19:45:44 kernel: [  936.814201] usb 4-2: Endpoint 1 MaxPacketSize 64
Feb 27 19:45:44 kernel: [  936.814205] usb 4-2: Endpoint 2 MaxPacketSize 64
Feb 27 19:45:44 kernel: [  936.814208] usb 4-2: Setting MaxPacketSize 64
Feb 27 19:45:44 kernel: [  936.816223] usb 4-2: FTDI USB Serial Device converter now attached to ttyUSB1
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Re: FTDI spontanteous disconnect/reconnect

[Greg KH]

On Thu, Apr 03, 2014 at 07:03:13PM +0200, Sven Lahr wrote:
> Hi there
> 
> I work for a company that produces a system that contains a device with an FTDI 232R chip, as well as a Linux (Debian) computer that the device is attached to.
> We often get reports from our customers that the device is
> disconnected, and then reconnected shortly thereafter. I have searched
> the web, and apparently quite a lot of people experience this when
> they use the Linux driver.

The driver can't disconnect itself from the bus, that sounds like an
electrical issue.

> I wonder if there is any plan to fix this. From what I can tell the
> Linux driver hasn't been updated in 5 years.

Where are you looking?  The in-kernel driver is updated all the time.

> 
> Below I have pasted the relevant part of my kernel log.
> 
> 
> Best regards
> Sven Lähr, Biotage AB, Sweden
> 
> Feb 27 19:45:44 kernel: [  936.368366] ftdi_sio ttyUSB0: FTDI USB Serial Device converter now disconnected from ttyUSB0
> Feb 27 19:45:44 kernel: [  936.368379] ftdi_sio 4-2:1.0: device disconnected
> Feb 27 19:45:44 kernel: [  936.608030] usb 4-2: new full-speed USB device number 3 using uhci_hcd
> Feb 27 19:45:44 kernel: [  936.806105] usb 4-2: New USB device found, idVendor=0403, idProduct=6001
> Feb 27 19:45:44 kernel: [  936.806110] usb 4-2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
> Feb 27 19:45:44 kernel: [  936.806115] usb 4-2: Product: FT232R USB UART
> Feb 27 19:45:44 kernel: [  936.806118] usb 4-2: Manufacturer: FTDI
> Feb 27 19:45:44 kernel: [  936.806121] usb 4-2: SerialNumber: A602WS4T
> Feb 27 19:45:44 kernel: [  936.814150] ftdi_sio 4-2:1.0: FTDI USB Serial Device converter detected
> Feb 27 19:45:44 kernel: [  936.814195] usb 4-2: Detected FT232RL
> Feb 27 19:45:44 kernel: [  936.814198] usb 4-2: Number of endpoints 2
> Feb 27 19:45:44 kernel: [  936.814201] usb 4-2: Endpoint 1 MaxPacketSize 64
> Feb 27 19:45:44 kernel: [  936.814205] usb 4-2: Endpoint 2 MaxPacketSize 64
> Feb 27 19:45:44 kernel: [  936.814208] usb 4-2: Setting MaxPacketSize 64
> Feb 27 19:45:44 kernel: [  936.816223] usb 4-2: FTDI USB Serial Device converter now attached to ttyUSB1

That shows the device disconnecting itself, and then coming back.
Perhaps something is lowering the voltage on the device such that the
host thinks it is gone?

Again, this isn't something that the driver can even do, so I'd start
looking for physical issues first.

thanks,

greg k-h
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FW: FTDI spontanteous disconnect/reconnect

[Sven Lahr]

Hi!

Thank you for your quick response. We will definitely look into the electronics.

But I am not quite sure what you mean when you say the in-kernel driver is up-to-date. Where can I find that information?
The only place I have found any information about ftdi_sio is the SourceForge page, which clearly states nothing has happened since 2009.
And I have really searched the web, specifically I was trying to find a "Known Issues" kinda page, bugtracker or something.

Regards
Sven Lähr

-----Original Message-----
From: Greg KH [mailto:gregkh@linuxfoundation.org]
Sent: Thursday, April 03, 2014 8:01 PM
To: Sven Lahr
Cc: linux-serial@vger.kernel.org
Subject: Re: FTDI spontanteous disconnect/reconnect

On Thu, Apr 03, 2014 at 07:03:13PM +0200, Sven Lahr wrote:
> Hi there
> 
> I work for a company that produces a system that contains a device with an FTDI 232R chip, as well as a Linux (Debian) computer that the device is attached to.
> We often get reports from our customers that the device is 
> disconnected, and then reconnected shortly thereafter. I have searched 
> the web, and apparently quite a lot of people experience this when 
> they use the Linux driver.

The driver can't disconnect itself from the bus, that sounds like an electrical issue.

> I wonder if there is any plan to fix this. From what I can tell the 
> Linux driver hasn't been updated in 5 years.

Where are you looking?  The in-kernel driver is updated all the time.

> 
> Below I have pasted the relevant part of my kernel log.
> 
> 
> Best regards
> Sven Lähr, Biotage AB, Sweden
> 
> Feb 27 19:45:44 kernel: [  936.368366] ftdi_sio ttyUSB0: FTDI USB 
> Serial Device converter now disconnected from ttyUSB0 Feb 27 19:45:44
> kernel: [  936.368379] ftdi_sio 4-2:1.0: device disconnected Feb 27
> 19:45:44 kernel: [  936.608030] usb 4-2: new full-speed USB device 
> number 3 using uhci_hcd Feb 27 19:45:44 kernel: [  936.806105] usb
> 4-2: New USB device found, idVendor=0403, idProduct=6001 Feb 27
> 19:45:44 kernel: [  936.806110] usb 4-2: New USB device strings: 
> Mfr=1, Product=2, SerialNumber=3 Feb 27 19:45:44 kernel: [ 936.806115] 
> usb 4-2: Product: FT232R USB UART Feb 27 19:45:44 kernel:
> [  936.806118] usb 4-2: Manufacturer: FTDI Feb 27 19:45:44 kernel: [ 
> 936.806121] usb 4-2: SerialNumber: A602WS4T Feb 27 19:45:44 kernel: [ 
> 936.814150] ftdi_sio 4-2:1.0: FTDI USB Serial Device converter 
> detected Feb 27 19:45:44 kernel: [  936.814195] usb 4-2: Detected 
> FT232RL Feb 27 19:45:44 kernel: [  936.814198] usb 4-2: Number of 
> endpoints 2 Feb 27 19:45:44 kernel: [  936.814201] usb 4-2: Endpoint 1 
> MaxPacketSize 64 Feb 27 19:45:44 kernel: [  936.814205] usb 4-2:
> Endpoint 2 MaxPacketSize 64 Feb 27 19:45:44 kernel: [  936.814208] usb
> 4-2: Setting MaxPacketSize 64 Feb 27 19:45:44 kernel: [  936.816223] 
> usb 4-2: FTDI USB Serial Device converter now attached to ttyUSB1

That shows the device disconnecting itself, and then coming back.
Perhaps something is lowering the voltage on the device such that the host thinks it is gone?

Again, this isn't something that the driver can even do, so I'd start looking for physical issues first.

thanks,

greg k-h
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RE: FTDI spontanteous disconnect/reconnect

[Mats Kärrman]

Hi Sven,

The FTDI driver is now developed as an integral part of the Linux kernel source tree.
See https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/drivers/usb/serial?id=refs/tags/v3.14
(or just www.kernel.org to start with)

BR // Mats
________________________________________
From: linux-serial-owner@vger.kernel.org [linux-serial-owner@vger.kernel.org] on behalf of Sven Lahr [Sven.Lahr@biotage.com]
Sent: Friday, April 04, 2014 8:13 AM
To: linux-serial@vger.kernel.org
Subject: FW: FTDI spontanteous disconnect/reconnect

Hi!

Thank you for your quick response. We will definitely look into the electronics.

But I am not quite sure what you mean when you say the in-kernel driver is up-to-date. Where can I find that information?
The only place I have found any information about ftdi_sio is the SourceForge page, which clearly states nothing has happened since 2009.
And I have really searched the web, specifically I was trying to find a "Known Issues" kinda page, bugtracker or something.

Regards
Sven Lähr

-----Original Message-----
From: Greg KH [mailto:gregkh@linuxfoundation.org]
Sent: Thursday, April 03, 2014 8:01 PM
To: Sven Lahr
Cc: linux-serial@vger.kernel.org
Subject: Re: FTDI spontanteous disconnect/reconnect

On Thu, Apr 03, 2014 at 07:03:13PM +0200, Sven Lahr wrote:
> Hi there
>
> I work for a company that produces a system that contains a device with an FTDI 232R chip, as well as a Linux (Debian) computer that the device is attached to.
> We often get reports from our customers that the device is
> disconnected, and then reconnected shortly thereafter. I have searched
> the web, and apparently quite a lot of people experience this when
> they use the Linux driver.

The driver can't disconnect itself from the bus, that sounds like an electrical issue.

> I wonder if there is any plan to fix this. From what I can tell the
> Linux driver hasn't been updated in 5 years.

Where are you looking?  The in-kernel driver is updated all the time.

>
> Below I have pasted the relevant part of my kernel log.
>
>
> Best regards
> Sven Lähr, Biotage AB, Sweden
>
> Feb 27 19:45:44 kernel: [  936.368366] ftdi_sio ttyUSB0: FTDI USB
> Serial Device converter now disconnected from ttyUSB0 Feb 27 19:45:44
> kernel: [  936.368379] ftdi_sio 4-2:1.0: device disconnected Feb 27
> 19:45:44 kernel: [  936.608030] usb 4-2: new full-speed USB device
> number 3 using uhci_hcd Feb 27 19:45:44 kernel: [  936.806105] usb
> 4-2: New USB device found, idVendor=0403, idProduct=6001 Feb 27
> 19:45:44 kernel: [  936.806110] usb 4-2: New USB device strings:
> Mfr=1, Product=2, SerialNumber=3 Feb 27 19:45:44 kernel: [ 936.806115]
> usb 4-2: Product: FT232R USB UART Feb 27 19:45:44 kernel:
> [  936.806118] usb 4-2: Manufacturer: FTDI Feb 27 19:45:44 kernel: [
> 936.806121] usb 4-2: SerialNumber: A602WS4T Feb 27 19:45:44 kernel: [
> 936.814150] ftdi_sio 4-2:1.0: FTDI USB Serial Device converter
> detected Feb 27 19:45:44 kernel: [  936.814195] usb 4-2: Detected
> FT232RL Feb 27 19:45:44 kernel: [  936.814198] usb 4-2: Number of
> endpoints 2 Feb 27 19:45:44 kernel: [  936.814201] usb 4-2: Endpoint 1
> MaxPacketSize 64 Feb 27 19:45:44 kernel: [  936.814205] usb 4-2:
> Endpoint 2 MaxPacketSize 64 Feb 27 19:45:44 kernel: [  936.814208] usb
> 4-2: Setting MaxPacketSize 64 Feb 27 19:45:44 kernel: [  936.816223]
> usb 4-2: FTDI USB Serial Device converter now attached to ttyUSB1

That shows the device disconnecting itself, and then coming back.
Perhaps something is lowering the voltage on the device such that the host thinks it is gone?

Again, this isn't something that the driver can even do, so I'd start looking for physical issues first.

thanks,

greg k-h
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Re: FW: FTDI spontanteous disconnect/reconnect

[Greg KH]

On Fri, Apr 04, 2014 at 08:13:01AM +0200, Sven Lahr wrote:
> Hi!
> 
> Thank you for your quick response. We will definitely look into the electronics.
> 
> But I am not quite sure what you mean when you say the in-kernel
> driver is up-to-date. Where can I find that information?
> The only place I have found any information about ftdi_sio is the
> SourceForge page, which clearly states nothing has happened since
> 2009.
> And I have really searched the web, specifically I was trying to find
> a "Known Issues" kinda page, bugtracker or something.

As Mats said, the driver is developed in the Linux kernel directly, like
almost all kernel drivers are.  There's no way we have individual pages
for each Linux driver, or have bug trackers like that, there are just
too many drivers that we support to do that.  The
linux-usb@vger.kernel.org mailing list is the place the driver is
discussed if you have any questions about it or the USB subsystem.

hope this helps,

greg k-h