diff options
Diffstat (limited to 'drivers/mtd/ubi/build.c')
| -rw-r--r-- | drivers/mtd/ubi/build.c | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c index 964a99d48bc..286ed594e5a 100644 --- a/drivers/mtd/ubi/build.c +++ b/drivers/mtd/ubi/build.c @@ -41,6 +41,7 @@ #include <linux/miscdevice.h> #include <linux/log2.h> #include <linux/kthread.h> +#include <linux/reboot.h> #include "ubi.h" /* Maximum length of the 'mtd=' parameter */ @@ -823,6 +824,34 @@ static int autoresize(struct ubi_device *ubi, int vol_id) } /** + * ubi_reboot_notifier - halt UBI transactions immediately prior to a reboot. + * @n: reboot notifier object + * @state: SYS_RESTART, SYS_HALT, or SYS_POWER_OFF + * @cmd: pointer to command string for RESTART2 + * + * This function stops the UBI background thread so that the flash device + * remains quiescent when Linux restarts the system. Any queued work will be + * discarded, but this function will block until do_work() finishes if an + * operation is already in progress. + * + * This function solves a real-life problem observed on NOR flashes when an + * PEB erase operation starts, then the system is rebooted before the erase is + * finishes, and the boot loader gets confused and dies. So we prefer to finish + * the ongoing operation before rebooting. + */ +static int ubi_reboot_notifier(struct notifier_block *n, unsigned long state, + void *cmd) +{ + struct ubi_device *ubi; + + ubi = container_of(n, struct ubi_device, reboot_notifier); + if (ubi->bgt_thread) + kthread_stop(ubi->bgt_thread); + ubi_sync(ubi->ubi_num); + return NOTIFY_DONE; +} + +/** * ubi_attach_mtd_dev - attach an MTD device. * @mtd: MTD device description object * @ubi_num: number to assign to the new UBI device @@ -978,6 +1007,11 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset) wake_up_process(ubi->bgt_thread); spin_unlock(&ubi->wl_lock); + /* Flash device priority is 0 - UBI needs to shut down first */ + ubi->reboot_notifier.priority = 1; + ubi->reboot_notifier.notifier_call = ubi_reboot_notifier; + register_reboot_notifier(&ubi->reboot_notifier); + ubi_devices[ubi_num] = ubi; ubi_notify_all(ubi, UBI_VOLUME_ADDED, NULL); return ubi_num; @@ -1049,6 +1083,7 @@ int ubi_detach_mtd_dev(int ubi_num, int anyway) * Before freeing anything, we have to stop the background thread to * prevent it from doing anything on this device while we are freeing. */ + unregister_reboot_notifier(&ubi->reboot_notifier); if (ubi->bgt_thread) kthread_stop(ubi->bgt_thread); |