On Fri, 5 Aug 2016, Robin Murphy wrote:

Hi Julia,

On 05/08/16 09:56, Julia Lawall wrote:

...

Use of_property_read_bool to check for the existence of a property.

This caught my eye since Rob told me off for doing the same recently[1].

...

The semantic patch that makes this change is as follows: (http://coccinelle.lip6.fr/)

// <smpl> @@ expression e1,e2; statement S2,S1; @@

•   if (of_get_property(e1,e2,NULL))
  

•   if (of_property_read_bool(e1,e2))
    S1 else S2
  

// </smpl>

Signed-off-by: Julia Lawall Julia.Lawall@lip6.fr

---

drivers/soc/ti/knav_qmss_queue.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/soc/ti/knav_qmss_queue.c b/drivers/soc/ti/knav_qmss_queue.c index b73e353..56b5d7c 100644 --- a/drivers/soc/ti/knav_qmss_queue.c +++ b/drivers/soc/ti/knav_qmss_queue.c @@ -1240,7 +1240,7 @@ static int knav_setup_queue_range(struct knav_device *kdev, if (of_get_property(node, "qalloc-by-id", NULL))

According to the binding, "qalloc-by-id" _is_ a boolean property, so this one really does deserve to be of_property_read_bool()...

...

range->flags |= RANGE_RESERVED;

• if (of_get_property(node, "accumulator", NULL)) {

• if (of_property_read_bool(node, "accumulator")) {

...whereas "accumulator" must have a value, so this isn't technically appropriate. In general, most of these "if the property exists, read the property and do stuff" checks are probably a sign of code that could be simplified by refactoring the "do stuff" step to just specifically handle the "read the property" step returning -EINVAL when it's not present.

Thanks for the very helpful feedback. I will rethink the patch set in light of this information.

julia

Robin.

...

ret = knav_init_acc_range(kdev, node, range);
if (ret < 0) {
	devm_kfree(dev, range);

---

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