Jakub Kicinski [mailto:jakub.kicinski@xxxxxxxxxxxxx] [...] > > static int rtl_stop_rx(struct r8152 *tp) > > { > > - int i; > > + struct list_head *cursor, *next, tmp_list; > > + unsigned long flags; > > + > > + INIT_LIST_HEAD(&tmp_list); > > > > - for (i = 0; i < RTL8152_MAX_RX; i++) > > - usb_kill_urb(tp->rx_info[i].urb); > > + /* The usb_kill_urb() couldn't be used in atomic. > > + * Therefore, move the list of rx_info to a tmp one. > > + * Then, list_for_each_safe could be used without > > + * spin lock. > > + */ > > Would you mind explaining in a little more detail why taking the > entries from the list for a brief period of time is safe? Usually, it needs the spin lock before accessing the entry of the list "tp->rx_info". However, for some reasons, if we want to access the entry without spin lock, we cloud move all entries to a local list temporally. Then, we could make sure no other one could access the entries included in the temporal local list. For this case, when I move all entries to a temporal local list, no other one could access them. Therefore, I could access the entries included in the temporal local list without spin lock. Best Regards, Hayes
