[PATCH] drivers/base: use READ_ONCE instead of deprecated ACCESS_ONCE

[PATCH] drivers/base: use READ_ONCE instead of deprecated ACCESS_ONCE

[Davidlohr Bueso]

With the new standardized functions, we can replace all ACCESS_ONCE()
calls across relevant drivers/base/.

ACCESS_ONCE() does not work reliably on non-scalar types. For example
gcc 4.6 and 4.7 might remove the volatile tag for such accesses during
the SRA (scalar replacement of aggregates) step:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58145

Update the new calls regardless of if it is a scalar type, this is
cleaner than having three alternatives.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
---
 drivers/base/core.c          | 2 +-
 drivers/base/power/runtime.c | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/base/core.c b/drivers/base/core.c
index ce057a568673..c0b3a2a03d72 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -101,7 +101,7 @@ const char *dev_driver_string(const struct device *dev)
 	 * so be careful about accessing it.  dev->bus and dev->class should
 	 * never change once they are set, so they don't need special care.
 	 */
-	drv = ACCESS_ONCE(dev->driver);
+	drv = READ_ONCE(dev->driver);
 	return drv ? drv->name :
 			(dev->bus ? dev->bus->name :
 			(dev->class ? dev->class->name : ""));
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
index 60ebb04d8140..747c19286250 100644
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -132,11 +132,11 @@ unsigned long pm_runtime_autosuspend_expiration(struct device *dev)
 	if (!dev->power.use_autosuspend)
 		goto out;
 
-	autosuspend_delay = ACCESS_ONCE(dev->power.autosuspend_delay);
+	autosuspend_delay = READ_ONCE(dev->power.autosuspend_delay);
 	if (autosuspend_delay < 0)
 		goto out;
 
-	last_busy = ACCESS_ONCE(dev->power.last_busy);
+	last_busy = READ_ONCE(dev->power.last_busy);
 	elapsed = jiffies - last_busy;
 	if (elapsed < 0)
 		goto out;	/* jiffies has wrapped around. */
-- 
2.6.6

Re: [PATCH] drivers/base: use READ_ONCE instead of deprecated ACCESS_ONCE

[Greg KH]

On Sat, Nov 19, 2016 at 11:52:48AM -0800, Davidlohr Bueso wrote:
> With the new standardized functions, we can replace all ACCESS_ONCE()
> calls across relevant drivers/base/.
> 
> ACCESS_ONCE() does not work reliably on non-scalar types. For example
> gcc 4.6 and 4.7 might remove the volatile tag for such accesses during
> the SRA (scalar replacement of aggregates) step:
> 
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58145
> 
> Update the new calls regardless of if it is a scalar type, this is
> cleaner than having three alternatives.
> 
> Signed-off-by: Davidlohr Bueso <dbueso@suse.de>

>From does not match signed-off-by, so I can't take this, sorry.

greg k-h

[PATCH v2] drivers/base: use READ_ONCE instead of deprecated ACCESS_ONCE

[Davidlohr Bueso]

With the new standardized functions, we can replace all ACCESS_ONCE()
calls across relevant drivers/base/.

ACCESS_ONCE() does not work reliably on non-scalar types. For example
gcc 4.6 and 4.7 might remove the volatile tag for such accesses during
the SRA (scalar replacement of aggregates) step:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58145

Update the new calls regardless of if it is a scalar type, this is
cleaner than having three alternatives.

Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>
---
 drivers/base/core.c          | 2 +-
 drivers/base/power/runtime.c | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/base/core.c b/drivers/base/core.c
index ce057a568673..c0b3a2a03d72 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -101,7 +101,7 @@ const char *dev_driver_string(const struct device *dev)
 	 * so be careful about accessing it.  dev->bus and dev->class should
 	 * never change once they are set, so they don't need special care.
 	 */
-	drv = ACCESS_ONCE(dev->driver);
+	drv = READ_ONCE(dev->driver);
 	return drv ? drv->name :
 			(dev->bus ? dev->bus->name :
 			(dev->class ? dev->class->name : ""));
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
index 60ebb04d8140..747c19286250 100644
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -132,11 +132,11 @@ unsigned long pm_runtime_autosuspend_expiration(struct device *dev)
 	if (!dev->power.use_autosuspend)
 		goto out;
 
-	autosuspend_delay = ACCESS_ONCE(dev->power.autosuspend_delay);
+	autosuspend_delay = READ_ONCE(dev->power.autosuspend_delay);
 	if (autosuspend_delay < 0)
 		goto out;
 
-	last_busy = ACCESS_ONCE(dev->power.last_busy);
+	last_busy = READ_ONCE(dev->power.last_busy);
 	elapsed = jiffies - last_busy;
 	if (elapsed < 0)
 		goto out;	/* jiffies has wrapped around. */
-- 
2.6.6

Re: [PATCH v2] drivers/base: use READ_ONCE instead of deprecated ACCESS_ONCE

[Greg KH]

On Wed, Nov 30, 2016 at 05:49:26AM -0800, Davidlohr Bueso wrote:
> With the new standardized functions, we can replace all ACCESS_ONCE()
> calls across relevant drivers/base/.
> 
> ACCESS_ONCE() does not work reliably on non-scalar types. For example
> gcc 4.6 and 4.7 might remove the volatile tag for such accesses during
> the SRA (scalar replacement of aggregates) step:
> 
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58145
> 
> Update the new calls regardless of if it is a scalar type, this is
> cleaner than having three alternatives.
> 
> Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>
> ---
> drivers/base/core.c          | 2 +-
> drivers/base/power/runtime.c | 4 ++--
> 2 files changed, 3 insertions(+), 3 deletions(-)

What changed from v1?  Please always include it below the --- line to
keep maintainer's semi-sane.

Try again?

thanks,

greg k-h

Re: [PATCH v2] drivers/base: use READ_ONCE instead of deprecated ACCESS_ONCE

[Davidlohr Bueso]

On Wed, 30 Nov 2016, Greg KH wrote:
>What changed from v1?  Please always include it below the --- line to
>keep maintainer's semi-sane.

If anything changed I would have -- this is only the From != SoB thing
you were complaining about. There's nothing to try again, this is a trivial.

Re: [PATCH v2] drivers/base: use READ_ONCE instead of deprecated ACCESS_ONCE

[Greg KH]

On Wed, Nov 30, 2016 at 09:02:49AM -0800, Davidlohr Bueso wrote:
> On Wed, 30 Nov 2016, Greg KH wrote:
> > What changed from v1?  Please always include it below the --- line to
> > keep maintainer's semi-sane.
> 
> If anything changed I would have -- this is only the From != SoB thing
> you were complaining about.

How am I supposed to remember that?  And that is a change, so please
list it.  Otherwise I just will drop it.

Remember, maintainers get hundreds of patches, and have no short term
memory at all, you have to remind them of everything.  That's your job.

> There's nothing to try again, this is a trivial.

a trivial what?

Anyway, you are going to have to fix it up if you want it accepted, it's
long gone from my patch queue...

thanks,

greg k-h