Messages in this thread | | | Date | Mon, 22 Feb 2010 15:12:41 -0500 (EST) | From | Alan Stern <> | Subject | Re: [REGRESSION] "USB: use kfifo to buffer usb-generic serial writes" causes gobi_loader to hang |
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On Mon, 22 Feb 2010, Matthew Garrett wrote:
> On Mon, Feb 22, 2010 at 02:10:33PM -0500, Alan Stern wrote: > > On Mon, 22 Feb 2010, Anssi Hannula wrote: > > > Does this mean a tty interface is ill-suited for the microcode upload, and > > > instead qcserial should use the kernel's generic microcode upload mechanism or > > > the userspace should use libusb to do it? > > > > I don't know. Didn't the old successful code use a tty interface? > > Yes. The kfifo changes have caused some sort of alteration in behaviour. > > > > Any idea what could be causing the hang, then? > > > > No idea, unless it's the device. > > Once the device hangs, it then tends to refuse any input until power > cycled. So it's clearly getting into some sort of undefined state, > though whether that's because it only gets sent half of its firmware > (ie, the hang occurs and as a result the hardware dies) or whether it's > causing the hang by dying is unclear.
The latest logs did show all the firmware getting sent -- or at least, they show that as much data was sent by the nonworking driver as by the working driver. So I'd say the device causes the hang by dying, although I don't know where the hang is or why a dead device should cause it.
Alan Stern
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