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| author | UCHINO Satoshi <satoshi.uchino@toshiba.co.jp> | 2013-05-23 11:10:11 +0900 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2013-07-27 05:34:08 +0100 |
| commit | c818402a62e9b82e5c8552479a2c56bb8cdca3d9 (patch) | |
| tree | 7d7cf9b8e3a2151fcf4769336b4cdb98e1f25286 /drivers/usb/gadget | |
| parent | c5c54396415c451ae4540bb23a0d8cc5f6d71d7d (diff) | |
| download | kernel_samsung_smdk4412-c818402a62e9b82e5c8552479a2c56bb8cdca3d9.zip kernel_samsung_smdk4412-c818402a62e9b82e5c8552479a2c56bb8cdca3d9.tar.gz kernel_samsung_smdk4412-c818402a62e9b82e5c8552479a2c56bb8cdca3d9.tar.bz2 | |
usb: gadget: f_mass_storage: add missing memory barrier for thread_wakeup_needed
commit d68c277b501889b3a50c179d1c3d704db7947b83 upstream.
Without this memory barrier, the file-storage thread may fail to
escape from the following while loop, because it may observe new
common->thread_wakeup_needed and old bh->state which are updated by
the callback functions.
/* Wait for the CBW to arrive */
while (bh->state != BUF_STATE_FULL) {
rc = sleep_thread(common);
if (rc)
return rc;
}
Signed-off-by: UCHINO Satoshi <satoshi.uchino@toshiba.co.jp>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'drivers/usb/gadget')
| -rw-r--r-- | drivers/usb/gadget/f_mass_storage.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/usb/gadget/f_mass_storage.c b/drivers/usb/gadget/f_mass_storage.c index a5570b6..8d7fb6b 100644 --- a/drivers/usb/gadget/f_mass_storage.c +++ b/drivers/usb/gadget/f_mass_storage.c @@ -512,6 +512,7 @@ static int fsg_set_halt(struct fsg_dev *fsg, struct usb_ep *ep) /* Caller must hold fsg->lock */ static void wakeup_thread(struct fsg_common *common) { + smp_wmb(); /* ensure the write of bh->state is complete */ /* Tell the main thread that something has happened */ common->thread_wakeup_needed = 1; if (common->thread_task) @@ -731,6 +732,7 @@ static int sleep_thread(struct fsg_common *common) } __set_current_state(TASK_RUNNING); common->thread_wakeup_needed = 0; + smp_rmb(); /* ensure the latest bh->state is visible */ return rc; } |