lkml.org 
[lkml]   [2014]   [Feb]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH v2 5/9] usb: don't use PREPARE_DELAYED_WORK
Hello,

If this is actually safe, let's do it from the get-go.

Thanks!
------- 8< -------
PREPARE_[DELAYED_]WORK() are being phased out. They have few users
and a nasty surprise in terms of reentrancy guarantee as workqueue
considers work items to be different if they don't have the same work
function.

usb_hub->init_work is multiplexed with multiple work functions;
however, the work item is never queued while in-flight, so we can
simply use INIT_DELAYED_WORK() before each queueing.

It would probably be best to route this with other related updates
through the workqueue tree.

Lightly tested.

v2: Greg and Alan confirm that the work item is never queued while
in-flight. Simply use INIT_DELAYED_WORK().

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: linux-usb@vger.kernel.org
---
drivers/usb/core/hub.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1040,7 +1040,7 @@ static void hub_activate(struct usb_hub
*/
if (type == HUB_INIT) {
delay = hub_power_on(hub, false);
- PREPARE_DELAYED_WORK(&hub->init_work, hub_init_func2);
+ INIT_DELAYED_WORK(&hub->init_work, hub_init_func2);
schedule_delayed_work(&hub->init_work,
msecs_to_jiffies(delay));

@@ -1194,7 +1194,7 @@ static void hub_activate(struct usb_hub

/* Don't do a long sleep inside a workqueue routine */
if (type == HUB_INIT2) {
- PREPARE_DELAYED_WORK(&hub->init_work, hub_init_func3);
+ INIT_DELAYED_WORK(&hub->init_work, hub_init_func3);
schedule_delayed_work(&hub->init_work,
msecs_to_jiffies(delay));
return; /* Continues at init3: below */

\
 
 \ /
  Last update: 2014-02-22 16:41    [W:0.208 / U:0.488 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site