On Tue, Apr 6, 2010 at 11:13 PM, Maulik <x0082077@xxxxxx> wrote: > >> -----Original Message----- >> From: linux-usb-owner@xxxxxxxxxxxxxxx [mailto:linux-usb- >> owner@xxxxxxxxxxxxxxx] On Behalf Of Maulik >> Sent: Tuesday, April 06, 2010 7:24 PM >> To: 'Alan Cox'; 'Greg KH' >> Cc: linux-usb@xxxxxxxxxxxxxxx >> Subject: RE: g_serial: scheduling while atomic bug >> >> > >> > Trace is fairly clear - someone has tty->low_latency set when they >> > shouldn't. As a result the push to the ldisc ran n_tty in the wrong >> > context. So its a driver bug. >> >> Yes I just found that disabling tty->low_latency in u_serial.c resolves >> the >> issue. >> > > The test works in the two cases as listed below for me. > > (1) Setting tty->low_latency = 0 in u_serial.c > (2) Using the patch at [1] which uses a workqueue instead of tasklet in > u_serial.c > > [1] http://marc.info/?l=linux-usb&m=126405382220848&w=2 > > > Cliff, > > You mentioned at [2] that "Disabling tty_low_latency doesn't work". > > Did you face any practical issues or was it related to theoretical concern > of "waking up the read thread right after calling tty_flip_buffer_push()"? > > [2] http://marc.info/?l=linux-usb&m=126408502425287&w=2 > > Yes,it will introduce another kind of crash in practice.The second solution works, but it seems that even with this patch,transfering a large file can cause data corruption. Cliff -- 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
