other: 0.186 semantic: 0.148 device: 0.109 performance: 0.078 vnc: 0.063 permissions: 0.057 PID: 0.052 graphic: 0.052 network: 0.049 debug: 0.047 socket: 0.047 files: 0.047 KVM: 0.033 boot: 0.032 debug: 0.209 device: 0.166 other: 0.106 performance: 0.106 files: 0.104 PID: 0.063 network: 0.056 semantic: 0.046 socket: 0.036 boot: 0.029 vnc: 0.024 permissions: 0.021 graphic: 0.018 KVM: 0.016 UHCI fails to signal stall response When TD execution results in STALL error (STALL handshake, no stall as a result of err count reaching 0), there is no way to know about it except for checking that TD. IMO it is an error condition and it should be reflected in the status register (and issue an interrupt if enabled). Ways to replicate: Send a query that is answered by stall (like set_idle request to a mouse) Expected behavior: UHCI hc sets status bit 1 (usb error interrupt) and issues an interrupt current behavior: Neither status bit is set nor interrupt triggered Version 0.14 attached patch for current master (quick fix, it might be I got something wrong) Hi, Thanks for reporting this issue. Just so you are aware: the qemu USB maintainer is probably going to be away for a while longer, so don't be too worried if this patch doesn't get looked at for 2-4 weeks. Brad No problem, it's not like it breaks something. This fix just makes driver development easier. On Thu, Apr 14, 2011 at 11:35 AM, jvesely