On Mon, 6 Jul 2009, Ramya Desai wrote: > On Mon, Jul 6, 2009 at 11:27 PM, Alan Stern<stern@xxxxxxxxxxxxxxxxxxx> wrote: > > On Mon, 6 Jul 2009, Ramya Desai wrote: > > > >> Dear Experts, > >> > >> Is there any limitation in calling usb_sg_init() from completion callback? > >> I am getting the srb structure parameters from URB context. > > > > You can call usb_sg_init from a completion callback, provided you pass > > it the GFP_ATOMIC memory flag. However you cannot call usb_sg_wait > > from a completion callback. > > > > Alan Stern > > If I schedule a tasklet, can I call usb_sg_wait() from that tasklet ?. Tasklets run in interrupt context, don't they? So the answer is No. As you can see from the kerneldoc in usb_sg_wait, it has to be called in process context. Alan Stern -- 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
