On Tue, Jun 6, 2017 at 3:33 PM, Alan Robertson <clinicalitltd@xxxxxxxxx> wrote: > On Tue, Jun 6, 2017 at 3:03 PM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: >> On Mon, 5 Jun 2017, Alan Robertson wrote: >>> > Try changing bcdDevice to a valid number, and change the serial number >>> > string to something different from what you were using before. >>> >>> Have changed both and also cleared Windows USB cache with DriveCleanup >>> from www.uwe-sieber.de (which forces redetection). Eject removable >>> media is showing as Cruzer Switch, but it is still showing as "Linux >>> File-Stor Gadget USB Device" in device manager (and as File-Stor on >>> other non-Windows devices I tried). >>> >>> I'm guessing we've now changed all that's changeable with >>> g_mass_storage but happy to take any further suggestions! - something >>> is still making it appear subtly different to systems cf a native USB >>> flash drive :( >> >> It's hard to say what that could be. From your description, the gadget >> does not send any information to the host that could identify it as a >> Linux-based gadget. > > Agree in lsusb -v there's nothing obvious, but the way File-Stor is > coming up on router & KDE and Windows is also identifying as that > (even after clearing devices and changing SN) make me think there must > be something that is still 'giving the game away'! Sadly I've got no > control of the devices I'm trying to use this in, I just know that > they're not recognising this as a valid memory stick when they will > happily recognise any other actual sticks that I try to use in them. > Sorry to return to this topic & appreciate it might be either specific to either the Pi or the system(s) I'm connecting it to, but have now had time to try a few more combinations out and would appreciate any thoughts from the experts here. To give some extra background - I've got the Pi configured to automatically overwrite the mass storage device filestore upon boot, so it is always presenting a fresh filesystem. Each system below is made by a different manufacturer and is a closed system, so I have no ability to perform any diagnostics at that end. System 1 - Always works System 2 - Shows no USB stick connected System 3 - Gives error when trying to save (memory error) System 4 - Says unidentified USB (Windows PC - Always works) (Linux PC - Always works) At first I thought this was due to minor subtleties of how the g_mass_storage device was being presented as a standard Sandisk USB memory stick works fine in all systems. However I then started to notice some unusual behaviour, if rather than doing a reboot (and wiping it fresh), I kept the power running and moved it between machines. If I started with System 1 first, then systems 2, 3, 4 would all recognise/write to it OK. I then copied a backup of the filesystem after it had been in System 1 - however that still didn't seem to solve the problem after a reboot. What I did then notice though was that if I powered the Pi up and then first connected it to a Windows system it then worked fine when plugged in to the others. To be clear I didn't read/write any files to the device, just started it up, then plugged it into Windows, saw the home directory on the USB open, then unplugged it and plugged it into one of the other systems - they all now recognised it. I tried starting/stopping g_mass_storage but that in itself didn't seem to do it. To be honest I'm now a bit flummoxed! It is clearly able to work with all 4 systems (I've been able to save files from them), but it seems to want to be plugged into either a PC or System 1 first before then working with the others. Can anyone think of anything that is happening when I do this? Unfortunately the idea of doing it this way is just not workable for what I'm wanting to do. Ideally I would have 1 Pi for each system, plugged into it just by the one USB data/power cable such that when the system powered on the Pi booted and then the USB was available to it to read/write. Thanks in advance for any thoughts. Alan -- 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
