(switched to email. Please respond via emailed reply-to-all, not via the bugzilla web interface). On Fri, 11 Sep 2009 13:49:50 GMT bugzilla-daemon@xxxxxxxxxxxxxxxxxxx wrote: > http://bugzilla.kernel.org/show_bug.cgi?id=14163 > > Summary: Data loss in CDC-ACM reception > Product: Drivers > Version: 2.5 > Kernel Version: 2.6.30.5 > Platform: All > OS/Version: Linux > Tree: Mainline > Status: NEW > Severity: normal > Priority: P1 > Component: USB > AssignedTo: greg@xxxxxxxxx > ReportedBy: ksb@xxxxxxxxxxxxxx > Regression: No > > > I have a CDC-ACM device sending pseudo random data as fast as possible. On my > computer I check the received sequence using a pseudo random generator > identical to the one in the device. On a 2.6.29.2 kernel this runs without any > errors. > On a 2.6.30.5 kernel it fails after approx. 1e6 bytes. > Using usbmon I can see that all data is correctly received but one packet (of > 128 bytes) is lost on it's way to the tty. > Checking git I found out that the older kernel hade the line > tty->low_latency = 1; > in cdc-acm.c > > After reintroducing that line into the driver it worked without errors agian. > I'll mark this as a regression. Can we just set ->low_latency again? What are the implications of that? -- 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
