On Thu, Sep 10, 2020 at 3:57 AM Hector Martin <hector@xxxxxxxxxxxxxx> wrote: > > On 10/09/2020 18.52, James Hilliard wrote: > > So I'm having trouble coming up with a reliable way to fix this in userspace, > > I've already got quite a few moving parts there as is and most of what I > > come up with seems like it would not work reliably, at least for automatically > > repairing the eeprom. > > I'm confused as to why this is hard to fix in userspace. You already > said you have userspace code binding to the proper VID/PID, so your code > won't find the bricked device. Then it's just a matter of having a udev > rule run the unbricker when it detects the bad device (which should > issue a USB reset when it's done reprogramming, making the device appear > as the right VID/PID), thus effectively doing the same thing the kernel > does. If this is embedded and not using udev, then substitute whatever > equivalent you have. If you're polling for the device at runtime instead > and don't have a device manager, just poll for the VID 0 device too and > apply the fix. Wouldn't you have to do a bunch of stuff like unbind the ftdi_sio driver before you can issue usb control commands from userspace? I haven't tested this yet but my assumption was that either a kernel driver or libusb can issue usb control messages, but both can not be bound to a device at the same time. I figured this wouldn't have come up when you tested your python script since the script likely predated adding the brick PID to the ftdi_sio Linux kernel driver. Maybe it makes sense to add a sysfs interface for reading/writing eeprom values without having to unbind the ftdi_sio driver. > > I can't think of a scenario where this would be difficult to fix in > userspace... > > -- > Hector Martin (hector@xxxxxxxxxxxxxx) > Public Key: https://mrcn.st/pub
