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Re: [PATCH] Create PNP device attributes via dev_attrs field of struct device

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[view original message]
From: Drew Moseley
Subject: [PATCH] Create PNP device attributes via dev_attrs field of struct device
Date: Tuesday, September 23, 2008 - 2:24 pm

Hello,

I have seen an issue where the sysfs entries for a PNP device are
created nonatomically resulting in a race condition with freedesktop
HAL.  The patch below is my first attempt at addressing this by creating
the device attributes as default bus attributes and allowing the
device_register() call to create them.  Any nasty side effects I am not
addressing?  Comments?

Regards,
Drew Moseley


Signed-off-by: Drew Moseley <dmoseley@mvista.com>
diff --git a/drivers/pnp/base.h b/drivers/pnp/base.h
index 9fd7bb9..b07787f 100644
--- a/drivers/pnp/base.h
+++ b/drivers/pnp/base.h
@@ -16,7 +16,7 @@ struct pnp_card *pnp_alloc_card(struct pnp_protocol *,
int id, char *pnpid);

 int pnp_add_device(struct pnp_dev *dev);
 struct pnp_id *pnp_add_id(struct pnp_dev *dev, char *id);
-int pnp_interface_attach_device(struct pnp_dev *dev);
+void pnp_interface_attach_device(struct pnp_dev *dev);

 int pnp_add_card(struct pnp_card *card);
 void pnp_remove_card(struct pnp_card *card);
diff --git a/drivers/pnp/core.c b/drivers/pnp/core.c
index a411582..bcd49ba 100644
--- a/drivers/pnp/core.c
+++ b/drivers/pnp/core.c
@@ -159,8 +159,6 @@ struct pnp_dev *pnp_alloc_dev(struct pnp_protocol
*protocol, int id, char *pnpid

 int __pnp_add_device(struct pnp_dev *dev)
 {
-	int ret;
-
 	pnp_fixup_device(dev);
 	dev->status = PNP_READY;
 	spin_lock(&pnp_lock);
@@ -168,12 +166,8 @@ int __pnp_add_device(struct pnp_dev *dev)
 	list_add_tail(&dev->protocol_list, &dev->protocol->devices);
 	spin_unlock(&pnp_lock);

-	ret = device_register(&dev->dev);
-	if (ret)
-		return ret;
-
 	pnp_interface_attach_device(dev);
-	return 0;
+	return device_register(&dev->dev);
 }

 /*
diff --git a/drivers/pnp/interface.c b/drivers/pnp/interface.c
index a876ecf..442684d 100644
--- a/drivers/pnp/interface.c
+++ b/drivers/pnp/interface.c
@@ -243,8 +243,6 @@ static ssize_t pnp_show_options(struct device *dmdev,
 	return ret;
 }

-static DEVICE_ATTR(options, S_IRUGO, pnp_show_options, NULL);
-
 static ...
[ message continues ]
[view original message]
From: Kay Sievers
Subject: Re: [PATCH] Create PNP device attributes via dev_attrs field of struct device
Date: Tuesday, September 23, 2008 - 9:59 pm

Any reason not to assign it statically to pnp_bus_type at in

Thanks,
Kay
--


[ message continues ]
[view original message]
From: Drew Moseley
Subject: Re: [PATCH] Create PNP device attributes via dev_attrs field of struct device
Date: Wednesday, September 24, 2008 - 10:22 am

Not really but since everything in the dev_attrs array is statically
defined in interface.c it was simpler to implement it this way.  To
assign it in driver.c, the array can be made non-static and an extern
added in driver.c, or the array definition can be moved to driver.c and
all the set and show functions be made non-static.  Is there a preference?

Thanks,
Drew
--


[ message continues ]
[view original message]
From: Kay Sievers
Subject: Re: [PATCH] Create PNP device attributes via dev_attrs field of struct device
Date: Wednesday, September 24, 2008 - 12:03 pm

Yeah, it looks weird to mangle the bus_type values from a device
routine, and set the same value again and again with every device
creation. Just declare the array non-static, if moving the code around
between files does not allow a static declaration.

Thanks,
Kay
--


[ message continues ]
[view original message]
From: Drew Moseley
Subject: Re: [PATCH] Create PNP device attributes via dev_attrs field of struct device
Date: Wednesday, September 24, 2008 - 12:37 pm

Updated patch.

Drew

Signed-off-by: Drew Moseley <dmoseley@mvista.com>
Index: linux-2.6.21/drivers/pnp/base.h
===================================================================
--- linux-2.6.21.orig/drivers/pnp/base.h
+++ linux-2.6.21/drivers/pnp/base.h
@@ -1,6 +1,5 @@
 extern spinlock_t pnp_lock;
 void *pnp_alloc(long size);
-int pnp_interface_attach_device(struct pnp_dev *dev);
 void pnp_fixup_device(struct pnp_dev *dev);
 void pnp_free_option(struct pnp_option *option);
 int __pnp_add_device(struct pnp_dev *dev);
Index: linux-2.6.21/drivers/pnp/core.c
===================================================================
--- linux-2.6.21.orig/drivers/pnp/core.c
+++ linux-2.6.21/drivers/pnp/core.c
@@ -111,7 +111,6 @@ static void pnp_release_device(struct de

 int __pnp_add_device(struct pnp_dev *dev)
 {
-	int ret;
 	pnp_fixup_device(dev);
 	dev->dev.bus = &pnp_bus_type;
 	dev->dev.release = &pnp_release_device;
@@ -120,11 +119,7 @@ int __pnp_add_device(struct pnp_dev *dev
 	list_add_tail(&dev->global_list, &pnp_global);
 	list_add_tail(&dev->protocol_list, &dev->protocol->devices);
 	spin_unlock(&pnp_lock);
-
-	ret = device_register(&dev->dev);
-	if (ret == 0)
-		pnp_interface_attach_device(dev);
-	return ret;
+	return device_register(&dev->dev);
 }

 /*
Index: linux-2.6.21/drivers/pnp/interface.c
===================================================================
--- linux-2.6.21.orig/drivers/pnp/interface.c
+++ linux-2.6.21/drivers/pnp/interface.c
@@ -233,9 +233,6 @@ static ssize_t pnp_show_options(struct d
 	return ret;
 }

-static DEVICE_ATTR(options,S_IRUGO,pnp_show_options,NULL);
-
-
 static ssize_t pnp_show_current_resources(struct device *dmdev, struct
device_attribute *attr, char *buf)
 {
 	struct pnp_dev *dev = to_pnp_dev(dmdev);
@@ -441,9 +438,6 @@ pnp_set_current_resources(struct device
 	return count;
 }

-static DEVICE_ATTR(resources,S_IRUGO | S_IWUSR,
-		   pnp_show_current_resources,pnp_set_current_resources);
-
 static ssize_t ...
[ message continues ]
[view original message]
From: Kay Sievers
Subject: Re: [PATCH] Create PNP device attributes via dev_attrs field of struct device
Date: Thursday, September 25, 2008 - 3:13 am

Thanks,
Kay
--


[ message continues ]
[view original message]
From: Drew Moseley
Subject: Re: [PATCH] Create PNP device attributes via dev_attrs field of struct device
Date: Thursday, September 25, 2008 - 9:42 am

Ack.  Sorry about that.  Wrong tree.  Here's the right one. ;-)

Signed-off-by: Drew Moseley <dmoseley@mvista.com>
diff --git a/drivers/pnp/base.h b/drivers/pnp/base.h
index 9fd7bb9..3532984 100644
--- a/drivers/pnp/base.h
+++ b/drivers/pnp/base.h
@@ -4,6 +4,7 @@
  */

 extern spinlock_t pnp_lock;
+extern struct device_attribute pnp_interface_attrs[];
 void *pnp_alloc(long size);

 int pnp_register_protocol(struct pnp_protocol *protocol);
@@ -16,7 +17,6 @@ struct pnp_card *pnp_alloc_card(struct pnp_protocol *,
int id, char *pnpid);

 int pnp_add_device(struct pnp_dev *dev);
 struct pnp_id *pnp_add_id(struct pnp_dev *dev, char *id);
-int pnp_interface_attach_device(struct pnp_dev *dev);

 int pnp_add_card(struct pnp_card *card);
 void pnp_remove_card(struct pnp_card *card);
diff --git a/drivers/pnp/core.c b/drivers/pnp/core.c
index a411582..7d65da8 100644
--- a/drivers/pnp/core.c
+++ b/drivers/pnp/core.c
@@ -159,21 +159,13 @@ struct pnp_dev *pnp_alloc_dev(struct pnp_protocol
*protocol, int id, char *pnpid

 int __pnp_add_device(struct pnp_dev *dev)
 {
-	int ret;
-
 	pnp_fixup_device(dev);
 	dev->status = PNP_READY;
 	spin_lock(&pnp_lock);
 	list_add_tail(&dev->global_list, &pnp_global);
 	list_add_tail(&dev->protocol_list, &dev->protocol->devices);
 	spin_unlock(&pnp_lock);
-
-	ret = device_register(&dev->dev);
-	if (ret)
-		return ret;
-
-	pnp_interface_attach_device(dev);
-	return 0;
+	return device_register(&dev->dev);
 }

 /*
diff --git a/drivers/pnp/driver.c b/drivers/pnp/driver.c
index d3f869e..e3f7e89 100644
--- a/drivers/pnp/driver.c
+++ b/drivers/pnp/driver.c
@@ -206,6 +206,7 @@ struct bus_type pnp_bus_type = {
 	.remove  = pnp_device_remove,
 	.suspend = pnp_bus_suspend,
 	.resume  = pnp_bus_resume,
+	.dev_attrs = pnp_interface_attrs,
 };

 int pnp_register_driver(struct pnp_driver *drv)
diff --git a/drivers/pnp/interface.c b/drivers/pnp/interface.c
index a876ecf..478a4a7 100644
--- a/drivers/pnp/interface.c
+++ ...
[ message continues ]
[view original message]
From: Kay Sievers
Subject: Re: [PATCH] Create PNP device attributes via dev_attrs field of struct device
Date: Saturday, September 27, 2008 - 4:31 pm

Looks good to me, and seems to work fine here. Thanks for the patch.

Greg, can you pick up the patch below?

Thanks,
Kay


From: Drew Moseley <dmoseley@mvista.com>
Subject: PNP: create device attributes via default device attributes

This creates the attributes before the uevent is sent.

Signed-off-by: Drew Moseley <dmoseley@mvista.com>
Acked-by: Kay Sievers <kay.sievers@vrfy.org>
---

diff --git a/drivers/pnp/base.h b/drivers/pnp/base.h
index 9fd7bb9..3532984 100644
--- a/drivers/pnp/base.h
+++ b/drivers/pnp/base.h
@@ -4,6 +4,7 @@
  */

 extern spinlock_t pnp_lock;
+extern struct device_attribute pnp_interface_attrs[];
 void *pnp_alloc(long size);

 int pnp_register_protocol(struct pnp_protocol *protocol);
@@ -16,7 +17,6 @@ struct pnp_card *pnp_alloc_card(struct pnp_protocol *, int id, char *pnpid);

 int pnp_add_device(struct pnp_dev *dev);
 struct pnp_id *pnp_add_id(struct pnp_dev *dev, char *id);
-int pnp_interface_attach_device(struct pnp_dev *dev);

 int pnp_add_card(struct pnp_card *card);
 void pnp_remove_card(struct pnp_card *card);
diff --git a/drivers/pnp/core.c b/drivers/pnp/core.c
index a411582..7d65da8 100644
--- a/drivers/pnp/core.c
+++ b/drivers/pnp/core.c
@@ -159,21 +159,13 @@ struct pnp_dev *pnp_alloc_dev(struct pnp_protocol *protocol, int id, char *pnpid

 int __pnp_add_device(struct pnp_dev *dev)
 {
-	int ret;
-
 	pnp_fixup_device(dev);
 	dev->status = PNP_READY;
 	spin_lock(&pnp_lock);
 	list_add_tail(&dev->global_list, &pnp_global);
 	list_add_tail(&dev->protocol_list, &dev->protocol->devices);
 	spin_unlock(&pnp_lock);
-
-	ret = device_register(&dev->dev);
-	if (ret)
-		return ret;
-
-	pnp_interface_attach_device(dev);
-	return 0;
+	return device_register(&dev->dev);
 }

 /*
diff --git a/drivers/pnp/driver.c b/drivers/pnp/driver.c
index d3f869e..e3f7e89 100644
--- a/drivers/pnp/driver.c
+++ b/drivers/pnp/driver.c
@@ -206,6 +206,7 @@ struct bus_type pnp_bus_type = {
 	.remove  = pnp_device_remove,
 	.suspend = ...
[ message continues ]
Previous thread: [patch 4/7] x86, cpa: dont use large pages for kernel identity mapping with DEBUG_PAGEALLOC by Suresh Siddha on Tuesday, September 23, 2008 - 2:00 pm. (1 message)

Next thread: SDHCI: timeout during data transfer by Luca Tettamanti on Tuesday, September 23, 2008 - 2:24 pm. (11 messages)