* [PATCH v1] of/platform: Unconditionally pause/resume sync state during kernel init
@ 2019-12-07 1:03 Saravana Kannan
2019-12-08 4:53 ` Frank Rowand
0 siblings, 1 reply; 2+ messages in thread
From: Saravana Kannan @ 2019-12-07 1:03 UTC (permalink / raw)
To: Rob Herring, Frank Rowand, Greg Kroah-Hartman, Saravana Kannan
Cc: kernel test robot, kernel-team, devicetree, linux-kernel
Commit 5e6669387e22 ("of/platform: Pause/resume sync state during init
and of_platform_populate()") paused/resumed sync state during init only
if Linux had parsed and populated a devicetree.
However, the check for that (of_have_populated_dt()) can change between
initcall levels when device tree unittests are enabled. This causes an
unmatched pause/resume of sync state. To avoid this, just
unconditionally pause/resume sync state during init.
Fixes: 5e6669387e22 ("of/platform: Pause/resume sync state during init and of_platform_populate()")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Saravana Kannan <saravanak@google.com>
---
drivers/of/platform.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index d93891a05f60..3371e4a06248 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -518,10 +518,11 @@ static int __init of_platform_default_populate_init(void)
{
struct device_node *node;
+ device_links_supplier_sync_state_pause();
+
if (!of_have_populated_dt())
return -ENODEV;
- device_links_supplier_sync_state_pause();
/*
* Handle certain compatibles explicitly, since we don't want to create
* platform_devices for every node in /reserved-memory with a
@@ -545,8 +546,7 @@ arch_initcall_sync(of_platform_default_populate_init);
static int __init of_platform_sync_state_init(void)
{
- if (of_have_populated_dt())
- device_links_supplier_sync_state_resume();
+ device_links_supplier_sync_state_resume();
return 0;
}
late_initcall_sync(of_platform_sync_state_init);
--
2.24.0.393.g34dc348eaf-goog
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH v1] of/platform: Unconditionally pause/resume sync state during kernel init
2019-12-07 1:03 [PATCH v1] of/platform: Unconditionally pause/resume sync state during kernel init Saravana Kannan
@ 2019-12-08 4:53 ` Frank Rowand
0 siblings, 0 replies; 2+ messages in thread
From: Frank Rowand @ 2019-12-08 4:53 UTC (permalink / raw)
To: Saravana Kannan, Rob Herring, Greg Kroah-Hartman
Cc: kernel test robot, kernel-team, devicetree, linux-kernel
On 12/6/19 7:03 PM, Saravana Kannan wrote:
> Commit 5e6669387e22 ("of/platform: Pause/resume sync state during init
> and of_platform_populate()") paused/resumed sync state during init only
> if Linux had parsed and populated a devicetree.
>
I _think_ (but I have not actually checked the code) that enabling unittests
is not the only way that of_root can be changed from NULL (thus changing
the value returned by of_have_populated_dt()). I _think_ that applying
an overlay on top of an empty devicetree will have the same result. So
I would change the following paragraph:
> However, the check for that (of_have_populated_dt()) can change between
> initcall levels when device tree unittests are enabled. This causes an
> unmatched pause/resume of sync state. To avoid this, just
> unconditionally pause/resume sync state during init.
to something like:
However, the check for that (of_have_populated_dt()) can change
after of_platform_default_populate_init() executes. One example
of this is when devicetree unittests are enabled. This causes an
nmatched pause/resume of sync state. To avoid this, just
unconditionally pause/resume sync state during init.
>
> Fixes: 5e6669387e22 ("of/platform: Pause/resume sync state during init and of_platform_populate()")
> Reported-by: kernel test robot <lkp@intel.com>
> Signed-off-by: Saravana Kannan <saravanak@google.com>
> ---
> drivers/of/platform.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/of/platform.c b/drivers/of/platform.c
> index d93891a05f60..3371e4a06248 100644
> --- a/drivers/of/platform.c
> +++ b/drivers/of/platform.c
> @@ -518,10 +518,11 @@ static int __init of_platform_default_populate_init(void)
> {
> struct device_node *node;
>
> + device_links_supplier_sync_state_pause();
> +
> if (!of_have_populated_dt())
> return -ENODEV;
>
> - device_links_supplier_sync_state_pause();
> /*
> * Handle certain compatibles explicitly, since we don't want to create
> * platform_devices for every node in /reserved-memory with a
> @@ -545,8 +546,7 @@ arch_initcall_sync(of_platform_default_populate_init);
>
> static int __init of_platform_sync_state_init(void)
> {
> - if (of_have_populated_dt())
> - device_links_supplier_sync_state_resume();
> + device_links_supplier_sync_state_resume();
> return 0;
> }
> late_initcall_sync(of_platform_sync_state_init);
>
Reviewed-by: Frank Rowand <frowand.list@gmail.com>
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