(switched to email. Please respond via emailed reply-to-all, not via the bugzilla web interface). On Mon, 29 Mar 2010 13:48:38 GMT bugzilla-daemon@xxxxxxxxxxxxxxxxxxx wrote: > https://bugzilla.kernel.org/show_bug.cgi?id=15649 > > Summary: Default scheduler not working, make > CONFIG_USB_EHCI_TT_NEWSCHED the default? > Product: Drivers > Version: 2.5 > Platform: All > OS/Version: Linux > Tree: Mainline > Status: NEW > Severity: normal > Priority: P1 > Component: USB > AssignedTo: greg@xxxxxxxxx > ReportedBy: jacob.benoit.1@xxxxxxxxx > Regression: No > > > I have met a situation where USB was not working correctly on my system, and > the fix was to build a kernel with CONFIG_USB_EHCI_TT_NEWSCHED enabled. So my > hope is that you will: > - either fix the default scheduler; > - or make CONFIG_USB_EHCI_TT_NEWSCHED the default. > > ==================================================== > Description of my problem with the default scheduler > ==================================================== > > I have a USB mouse and a USB audio DAC. > > Both work fine separately on my system (linux 2.6.33, x86-64, distro: Arch > Linux). > > The problem is when I try using both simultaneously. The first-plugged device > will work fine, but not the second-plugged device. For example, if I plug the > audio DAC first and the mouse second, then the audio DAC works and the mouse > doesn't work. And conversely. > > If I then unplug the first-plugged device and plug the other one, then it > works. No need to reboot. > > When I say that the second-plugged device doesn't work, here's what I mean: the > USB device is detected by the system, but gets "reset" every 2 seconds and > can't be actually used at all. > > Here are some log messages. > > lsusb output: > > $ lsusb | egrep -i mouse\|texas > Bus 002 Device 009: ID 08bb:2704 Texas Instruments Japan > Bus 002 Device 007: ID 046d:c526 Logitech, Inc. MX Revolution Cordless Mouse > > Here, "Texas Instruments Japan" is my audio DAC. So, at the level of lsusb, all > is well. > > Now here's what dmesg says when I plug the second device: > > usb 2-1.1: reset full speed USB device using ehci_hcd and address 4 > usb 2-1.1: reset full speed USB device using ehci_hcd and address 4 > usb 2-1.1: reset full speed USB device using ehci_hcd and address 4 > cannot submit datapipe for urb 0, error -28: not enough bandwidth > cannot submit datapipe for urb 0, error -28: not enough bandwidth > cannot submit datapipe for urb 0, error -28: not enough bandwidth > cannot submit datapipe for urb 0, error -28: not enough bandwidth > cannot submit datapipe for urb 0, error -28: not enough bandwidth > cannot submit datapipe for urb 0, error -28: not enough bandwidth > cannot submit datapipe for urb 0, error -28: not enough bandwidth > cannot submit datapipe for urb 0, error -28: not enough bandwidth > > The second-plugged device then doesn't work at all. > > The problem only happens with this precise combination of USB devices (mouse > and DAC). > > =========================== > Description of the solution > =========================== > > Compiled a vanilla kernel 2.6.33.1 with my current /proc/config.gz and only > this option changed: CONFIG_USB_EHCI_TT_NEWSCHED set to Yes. > > This fixed the problem immediately. > > Note also that my distro, Arch linux, doesn't patch much (if at all) kernels. > Thus it is very reasonable to assume that CONFIG_USB_EHCI_TT_NEWSCHED is what > fixed this problem. > > ================= > What I would like > ================= > > I would like Linux's default USB scheduler to be clever enough that I don't > have to compile custom kernels again in the future :) > > Thanks for listening. -- 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
