On Tue, Jun 25, 2013 at 09:25:50AM -0400, raespi wrote: > Hi ... I'm using an ARM Samsung S3C24XX processor with a 3.1.10 > kernel. Note, this is a very old and unsupported kernel version, you really should consider upgrading, or getting support for these types of issues from the vendor that is forcing you to use this kernel version. > I'm interested in creating medical equipment using Linux > and came onto an issue today. I've created an application that > connects to two FTDI devices and reads continuous data from a > medical sensor. I have a custom based board ( no external ports ), > and my FTDI devices go directly to the S3C24xx USB pins and my app > is configured to read from a specific product, vendor and device > address location. I've been testing it without problems and today > it stopped working. Apparently, when checking the *dmesg* messages, > the kernel disconnected those two USB devices and assigned them two > new addresses ( 5 and 6 ) different from the original 3 and 4. I > always noticed on PC's that this issue was somehow related to > hardware problems and/or disconnection from the USB port. Also both > the /dev/ttyUSB0 and /dev/ttyUSB1 devices on the /dev directory > dissapeared ( for now not a problem since I don't access the FTDI > device this way ). How are you accessing the FTDI devices, if not through their ttyUSB ports? Your system should also have some persistant device names for these ports in the /dev/serial/ directory if you are using udev. I'd recommend using them and making sure each of these devices has a unique serial number, in order to always know you are talking to the correct device. good luck, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
