mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
* [PATCH] device_shutdown can loop if the driver frees itself
@ 2006-01-04 20:31 Michael Richardson
  0 siblings, 0 replies; 2+ messages in thread
From: Michael Richardson @ 2006-01-04 20:31 UTC (permalink / raw)
  To: mochel; +Cc: linux-kernel

[-- Attachment #1: Type: text/plain, Size: 2443 bytes --]


This patch changes device_shutdown() to use a newly introduce safe
reverse list traversal.  We experienced loops on system reboot if we had
removed and re-inserted our device from the device list. 

We noticed this problem on PPC405. Our PCI IDE device comes and goes a lot.

Our hypothesis was that there was a loop caused by the driver->shutdown
freeing memory.  It is possible that we do something wrong as well, but
being unable to reboot is kind of nasty.

Signed-off-by: Michael Richardson <mcr@marajade.sandelman.ca>

---

 drivers/base/power/shutdown.c |    4 ++--
 include/linux/list.h          |   13 +++++++++++++
 2 files changed, 15 insertions(+), 2 deletions(-)

applies-to: 96a0b5842e24d6736c698cdbd820a3ad9d8d9f10
49291875d63ec697510fc4cc9a1766b7400ee2d3
diff --git a/drivers/base/power/shutdown.c b/drivers/base/power/shutdown.c
index f50a08b..3a417c8 100644
--- a/drivers/base/power/shutdown.c
+++ b/drivers/base/power/shutdown.c
@@ -35,10 +35,10 @@ extern int sysdev_shutdown(void);
  */
 void device_shutdown(void)
 {
-	struct device * dev;
+	struct device * dev, *devn;
 
 	down_write(&devices_subsys.rwsem);
-	list_for_each_entry_reverse(dev, &devices_subsys.kset.list,
+	list_for_each_entry_safe_reverse(dev, devn, &devices_subsys.kset.list,
 				kobj.entry) {
 		if (dev->driver && dev->driver->shutdown) {
 			dev_dbg(dev, "shutdown\n");
diff --git a/include/linux/list.h b/include/linux/list.h
index 8e33882..b31ec32 100644
--- a/include/linux/list.h
+++ b/include/linux/list.h
@@ -436,6 +436,19 @@ static inline void list_splice_init(stru
 	     pos = n, n = list_entry(n->member.next, typeof(*n), member))
 
 /**
+ * list_for_each_entry_safe_reverse - iterate backwards over list of given type safe against removal of list entry
+ * @pos:	the type * to use as a loop counter.
+ * @n:          another type * to use as temporary storage
+ * @head:	the head for your list.
+ * @member:	the name of the list_struct within the struct.
+ */
+#define list_for_each_entry_safe_reverse(pos, n, head, member)		\
+	for (pos = list_entry((head)->prev, typeof(*pos), member),	\
+		     n = list_entry(pos->member.next, typeof(*pos), member); \
+	     &pos->member != (head); 	\
+	     pos = n, n = list_entry(n->member.prev, typeof(*n), member))
+
+/**
  * list_for_each_rcu	-	iterate over an rcu-protected list
  * @pos:	the &struct list_head to use as a loop counter.
  * @head:	the head for your list.
---
0.99.9.GIT







[-- Attachment #2: Type: application/pgp-signature, Size: 480 bytes --]

^ permalink raw reply	[flat|nested] 2+ messages in thread
* [PATCH] Remove usb gadget generic driver methods
@ 2006-01-13 19:50 Greg KH
  2006-01-13 19:50 ` [PATCH] device_shutdown can loop if the driver frees itself Greg KH
  0 siblings, 1 reply; 2+ messages in thread
From: Greg KH @ 2006-01-13 19:50 UTC (permalink / raw)
  To: linux-kernel; +Cc: rmk

[PATCH] Remove usb gadget generic driver methods

USB gadget drivers make no use of these, remove the pointless
comments.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
commit d78967fb035aeb839a047ae69ce5f1ff39288a8d
tree e76337604583e4052b8a685223af1d342f40ad19
parent 4031bbe4bbec6c0fe50412ef7fb43a270b0f29f1
author Russell King <rmk@arm.linux.org.uk> Fri, 06 Jan 2006 11:41:32 +0000
committer Greg Kroah-Hartman <gregkh@suse.de> Fri, 13 Jan 2006 11:26:11 -0800

 drivers/usb/gadget/ether.c  |    3 ---
 drivers/usb/gadget/inode.c  |    3 ---
 drivers/usb/gadget/serial.c |    3 ---
 drivers/usb/gadget/zero.c   |    3 ---
 4 files changed, 0 insertions(+), 12 deletions(-)

diff --git a/drivers/usb/gadget/ether.c b/drivers/usb/gadget/ether.c
index 8f402f8..afc84cf 100644
--- a/drivers/usb/gadget/ether.c
+++ b/drivers/usb/gadget/ether.c
@@ -2534,9 +2534,6 @@ static struct usb_gadget_driver eth_driv
 	.driver 	= {
 		.name		= (char *) shortname,
 		.owner		= THIS_MODULE,
-		// .shutdown = ...
-		// .suspend = ...
-		// .resume = ...
 	},
 };
 
diff --git a/drivers/usb/gadget/inode.c b/drivers/usb/gadget/inode.c
index c6c279d..9a4edc5 100644
--- a/drivers/usb/gadget/inode.c
+++ b/drivers/usb/gadget/inode.c
@@ -1738,9 +1738,6 @@ static struct usb_gadget_driver gadgetfs
 
 	.driver 	= {
 		.name		= (char *) shortname,
-		// .shutdown = ...
-		// .suspend = ...
-		// .resume = ...
 	},
 };
 
diff --git a/drivers/usb/gadget/serial.c b/drivers/usb/gadget/serial.c
index 2e6926b..ba9acd5 100644
--- a/drivers/usb/gadget/serial.c
+++ b/drivers/usb/gadget/serial.c
@@ -374,9 +374,6 @@ static struct usb_gadget_driver gs_gadge
 	.disconnect =		gs_disconnect,
 	.driver = {
 		.name =		GS_SHORT_NAME,
-		/* .shutdown = ... */
-		/* .suspend = ...  */
-		/* .resume = ...   */
 	},
 };
 
diff --git a/drivers/usb/gadget/zero.c b/drivers/usb/gadget/zero.c
index 6c58636..2fc110d 100644
--- a/drivers/usb/gadget/zero.c
+++ b/drivers/usb/gadget/zero.c
@@ -1303,9 +1303,6 @@ static struct usb_gadget_driver zero_dri
 	.driver 	= {
 		.name		= (char *) shortname,
 		.owner		= THIS_MODULE,
-		// .shutdown = ...
-		// .suspend = ...
-		// .resume = ...
 	},
 };
 


^ permalink raw reply	[flat|nested] 2+ messages in thread
end of thread, other threads:[~2006-01-13 19:50 UTC | newest]

Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2006-01-04 20:31 [PATCH] device_shutdown can loop if the driver frees itself Michael Richardson
2006-01-13 19:50 [PATCH] Remove usb gadget generic driver methods Greg KH
2006-01-13 19:50 ` [PATCH] device_shutdown can loop if the driver frees itself Greg KH

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®