2016-10-11 19:41:12

by Rob Herring (Arm)

Subject: [PATCH 1/2] driver core: skip removal test for non-removable drivers

Some drivers do not support removal/unbinding. These drivers should have
drv->suppress_bind_attrs set to true, so use that to skip the removal
test.

This doesn't fix anything reported so far, but should prevent some other
cases. Some drivers will need fixes to set suppress_bind_attrs to avoid
this test.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=177021
Fixes: bea5b158ff0d ("driver core: add test of driver remove calls during probe")
Reported-by: Laszlo Ersek <[email protected]>
Signed-off-by: Rob Herring <[email protected]>
---
drivers/base/dd.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index d22a7260f42b..8937a7ad7165 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -324,7 +324,8 @@ static int really_probe(struct device *dev, struct device_driver *drv)
{
int ret = -EPROBE_DEFER;
int local_trigger_count = atomic_read(&deferred_trigger_count);
- bool test_remove = IS_ENABLED(CONFIG_DEBUG_TEST_DRIVER_REMOVE);
+ bool test_remove = IS_ENABLED(CONFIG_DEBUG_TEST_DRIVER_REMOVE) &&
+ !drv->suppress_bind_attrs;

if (defer_all_probes) {
/*
--
2.10.0

2016-10-11 19:46:57

by Rob Herring (Arm)

Subject: [PATCH 2/2] driver core: fix smatch warning on dev->bus check

Commit d42a09802174 (driver core: skip removal test for non-removable
drivers) introduced a smatch warning:

drivers/base/dd.c:386 really_probe()
warn: variable dereferenced before check 'dev->bus' (see line 373)

Fix the warning by removing the dev->bus NULL check. dev->bus will never
be NULL, so the check was unnecessary.

Reported-by: Dan Carpenter <[email protected]>
Signed-off-by: Rob Herring <[email protected]>
---
drivers/base/dd.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index 8937a7ad7165..d76cd97a98b6 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -384,7 +384,7 @@ static int really_probe(struct device *dev, struct device_driver *drv)
if (test_remove) {
test_remove = false;

- if (dev->bus && dev->bus->remove)
+ if (dev->bus->remove)
dev->bus->remove(dev);
else if (drv->remove)
drv->remove(dev);
--
2.10.0

2016-10-12 07:10:33

by Laszlo Ersek

Subject: Re: [PATCH 1/2] driver core: skip removal test for non-removable drivers

Hi Rob,

On 10/11/16 20:41, Rob Herring wrote:
> Some drivers do not support removal/unbinding. These drivers should have
> drv->suppress_bind_attrs set to true, so use that to skip the removal
> test.
>
> This doesn't fix anything reported so far, but should prevent some other
> cases. Some drivers will need fixes to set suppress_bind_attrs to avoid
> this test.
>
> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=177021
> Fixes: bea5b158ff0d ("driver core: add test of driver remove calls during probe")
> Reported-by: Laszlo Ersek <[email protected]>
> Signed-off-by: Rob Herring <[email protected]>
> ---
> drivers/base/dd.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/base/dd.c b/drivers/base/dd.c
> index d22a7260f42b..8937a7ad7165 100644
> --- a/drivers/base/dd.c
> +++ b/drivers/base/dd.c
> @@ -324,7 +324,8 @@ static int really_probe(struct device *dev, struct device_driver *drv)
> {
> int ret = -EPROBE_DEFER;
> int local_trigger_count = atomic_read(&deferred_trigger_count);
> - bool test_remove = IS_ENABLED(CONFIG_DEBUG_TEST_DRIVER_REMOVE);
> + bool test_remove = IS_ENABLED(CONFIG_DEBUG_TEST_DRIVER_REMOVE) &&
> + !drv->suppress_bind_attrs;
>
> if (defer_all_probes) {
> /*
>

can you please repost the full series with me CC'd on all of the
messages; I'm not subscribed to LKML.

Thanks,
Laszlo