Device node iterators put the previous value of the index variable,
so an explicit put causes a double put.
I detect the issue with the help of Coccinelle.
Signed-off-by: zhong jiang <redacted>
---
arch/arm/mach-at91/pm.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)
diff --git a/arch/arm/mach-at91/pm.c b/arch/arm/mach-at91/pm.c
index 32fae4d..a5ec35f 100644
--- a/arch/arm/mach-at91/pm.c
+++ b/arch/arm/mach-at91/pm.c
@@ -143,15 +143,12 @@ static int at91_pm_config_ws(unsigned int pm_mode, bool set)
/* Check if enabled on SHDWC. */
if (wsi->shdwc_mr_bit && !(val & wsi->shdwc_mr_bit))
- goto put_node;
+ continue;
mode |= wsi->pmc_fsmr_bit;
if (wsi->set_polarity)
polarity |= wsi->pmc_fsmr_bit;
}
-
-put_node:
- of_node_put(np);
}
if (mode) {--
1.7.12.4
On 14/08/2018 09:54:56+0800, zhong jiang wrote:
Device node iterators put the previous value of the index variable,
so an explicit put causes a double put.
While for_each_matching_node_and_match will get and put the node
properly, there is also a call to of_find_device_by_node that will get a
reference to the node.
quoted hunk
I detect the issue with the help of Coccinelle.
Signed-off-by: zhong jiang <redacted>
---
arch/arm/mach-at91/pm.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)
diff --git a/arch/arm/mach-at91/pm.c b/arch/arm/mach-at91/pm.c
index 32fae4d..a5ec35f 100644
--- a/arch/arm/mach-at91/pm.c
+++ b/arch/arm/mach-at91/pm.c
@@ -143,15 +143,12 @@ static int at91_pm_config_ws(unsigned int pm_mode, bool set)
/* Check if enabled on SHDWC. */
if (wsi->shdwc_mr_bit && !(val & wsi->shdwc_mr_bit))
- goto put_node;
+ continue;
mode |= wsi->pmc_fsmr_bit;
if (wsi->set_polarity)
polarity |= wsi->pmc_fsmr_bit;
}
-
-put_node:
- of_node_put(np);
}
if (mode) {--
1.7.12.4
--
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
Hi Alexandre,
On 14.08.2018 15:59, Alexandre Belloni wrote:
On 14/08/2018 09:54:56+0800, zhong jiang wrote:
quoted
Device node iterators put the previous value of the index variable,
so an explicit put causes a double put.
While for_each_matching_node_and_match will get and put the node
properly, there is also a call to of_find_device_by_node that will get a
reference to the node.
Looking through of_find_device_by_node() it seems that a put_device() on the
struct device member of the returned struct platform_device has to be called
instead of of_node_put().
of_find_device_by_node() calls bus_find_device():
dev = bus_find_device(&platform_bus_type, NULL, np, of_dev_node_match);
the match function, of_dev_node_match(), is just as follows:
static int of_dev_node_match(struct device *dev, void *data)
{
return dev->of_node == data;
}
but bus_find_device() takes a reference to the struct device returned in case it
founds a match, via get_device():
struct device *bus_find_device(struct bus_type *bus,
struct device *start, void *data,
int (*match)(struct device *dev,
void*data))
{
struct klist_iter i;
struct device *dev;
if (!bus || !bus->p)
return NULL;
klist_iter_init_node(&bus->p->klist_devices, &i,
(start ? &start->p->knode_bus : NULL));
while ((dev = next_device(&i)))
if (match(dev, data) && get_device(dev))
break;
klist_iter_exit(&i);
return dev;
}
So, I think a put_device(&pdev->dev) has to be called in at91_pm_config_ws()
instead of of_node_put(np). My bad!
Thank you,
Claudiu Beznea
quoted
I detect the issue with the help of Coccinelle.
Signed-off-by: zhong jiang <redacted>
---
arch/arm/mach-at91/pm.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)
diff --git a/arch/arm/mach-at91/pm.c b/arch/arm/mach-at91/pm.c
index 32fae4d..a5ec35f 100644
--- a/arch/arm/mach-at91/pm.c
+++ b/arch/arm/mach-at91/pm.c
@@ -143,15 +143,12 @@ static int at91_pm_config_ws(unsigned int pm_mode, bool set)
/* Check if enabled on SHDWC. */
if (wsi->shdwc_mr_bit && !(val & wsi->shdwc_mr_bit))
- goto put_node;
+ continue;
mode |= wsi->pmc_fsmr_bit;
if (wsi->set_polarity)
polarity |= wsi->pmc_fsmr_bit;
}
-
-put_node:
- of_node_put(np);
}
if (mode) {--
1.7.12.4
On 2018/8/16 17:32, Claudiu Beznea wrote:
Hi Alexandre,
On 14.08.2018 15:59, Alexandre Belloni wrote:
quoted
On 14/08/2018 09:54:56+0800, zhong jiang wrote:
quoted
Device node iterators put the previous value of the index variable,
so an explicit put causes a double put.
While for_each_matching_node_and_match will get and put the node
properly, there is also a call to of_find_device_by_node that will get a
reference to the node.
Looking through of_find_device_by_node() it seems that a put_device() on the
struct device member of the returned struct platform_device has to be called
instead of of_node_put().
of_find_device_by_node() calls bus_find_device():
dev = bus_find_device(&platform_bus_type, NULL, np, of_dev_node_match);
the match function, of_dev_node_match(), is just as follows:
static int of_dev_node_match(struct device *dev, void *data)
{
return dev->of_node == data;
}
but bus_find_device() takes a reference to the struct device returned in case it
founds a match, via get_device():
struct device *bus_find_device(struct bus_type *bus,
struct device *start, void *data,
int (*match)(struct device *dev,
void*data))
{
struct klist_iter i;
struct device *dev;
if (!bus || !bus->p)
return NULL;
klist_iter_init_node(&bus->p->klist_devices, &i,
(start ? &start->p->knode_bus : NULL));
while ((dev = next_device(&i)))
if (match(dev, data) && get_device(dev))
break;
klist_iter_exit(&i);
return dev;
}
So, I think a put_device(&pdev->dev) has to be called in at91_pm_config_ws()
instead of of_node_put(np). My bad!
Yes, you're right. Thanks, Claudiu. I will repost in v2.
Sincerely,
zhong jiang
Thank you,
Claudiu Beznea
quoted
quoted
I detect the issue with the help of Coccinelle.
Signed-off-by: zhong jiang <redacted>
---
arch/arm/mach-at91/pm.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)
diff --git a/arch/arm/mach-at91/pm.c b/arch/arm/mach-at91/pm.c
index 32fae4d..a5ec35f 100644
--- a/arch/arm/mach-at91/pm.c
+++ b/arch/arm/mach-at91/pm.c
@@ -143,15 +143,12 @@ static int at91_pm_config_ws(unsigned int pm_mode, bool set)
/* Check if enabled on SHDWC. */
if (wsi->shdwc_mr_bit && !(val & wsi->shdwc_mr_bit))
- goto put_node;
+ continue;
mode |= wsi->pmc_fsmr_bit;
if (wsi->set_polarity)
polarity |= wsi->pmc_fsmr_bit;
}
-
-put_node:
- of_node_put(np);
}
if (mode) {--
1.7.12.4
.