Messages in this thread | | | Date | Mon, 9 Mar 2009 12:15:29 -0400 (EDT) | From | Alan Stern <> | Subject | Re: [BUG] Loading both ehci-hcd and uhci-hcd drivers causes my printer to fail |
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On Mon, 9 Mar 2009, Maxim Levitsky wrote:
> > Is your printer connected directly to the computer, or does it go > > through a hub? (If it is connected directly then EHCI_TT_NEWSCHED > > should not affect it at all.) > > > > If it does go through a hub, does it behave better when you attach it > > directly? > > > > Alan Stern > > > No, it is connected directly. > Just tried 'bad' driver, and firmware upload failed > > Do you mean that CONFIG_USB_EHCI_TT_NEWSCHED doesn't affect the driver > at all when no hub is presented?
That's right. Transaction Translators (TTs) live inside hubs. If you don't use a hub then the TT code never runs.
> Btw, at least according to lsusb -t, there are no internal hubs in the > printer.
What does /proc/bus/usb/devices say?
> But it can be a coincidence, it seems that with 'bad' driver printer > works 'better' to as it failed back few days ago much more often, maybe > cable is bad, don't know, but according to the web these printers > 1018/1020.. have usb problems, there is even a readme for that in > foo2zjz > > I try to use the 'good' driver > (without CONFIG_USB_EHCI_TT_NEWSCHED) for some time.
Please don't forget to collect usbmon traces when the problem occurs.
Alan Stern
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