On Tuesday 23 June 2009, Marek Szyprowski wrote: > /* low_latency means ldiscs work in tasklet context, without > * needing a workqueue schedule ... easier to keep up. > */ > > So in low latency mode calls are made from a tasklet. ... and that has, at some point since 2.6.26 or so, become a problem that caused oopsing. > This is not true in > my case, as the S3C OTG UDC driver does all its job in interrupts. This > way also a (usb) packet_done callback is done from an interrupt. I expect > that g_serial driver interacts with tty layer in that packet_done callback, > so this is the source of the problems. I noticed that some other UDC > drivers also does all its job from an interrupt, so they also might be > affected. How this bug should be properly resolved? Change the u_serial.c code so that this newish tty behavior stops causing problems: don't set low_latency. But also try and sort through any consequences of that, and don't forget to update the comments which talk about how the low_latency setting is affecting code flow. - Dave -- 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
