[PATCH 0/2] Revert "device property: Keep secondary firmware node secondary by type"

[PATCH 0/2] Revert "device property: Keep secondary firmware node secondary by type"

[Bard Liao]

While the commit d5dcce0 ("device property: Keep secondary firmware
node secondary by type")
describes everything correct in its commit message the change it made does
the opposite and original commit c15e1bd ("device property: Fix the
secondary firmware node handling in set_primary_fwnode()") was fully
correct. Thus, revert the former one here and improve documentation.

Bard Liao (2):
  Revert "device property: Keep secondary firmware node secondary by
    type"
  device property: add description of fwnode cases

 drivers/base/core.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

-- 
2.17.1

[PATCH 1/2] Revert "device property: Keep secondary firmware node secondary by type"

[Bard Liao]

While the commit d5dcce0c414f ("device property: Keep secondary firmware
node secondary by type")
describes everything correct in its commit message the change it made does
the opposite and original commit c15e1bdda436 ("device property: Fix the
secondary firmware node handling in set_primary_fwnode()") was fully
correct. Thus, revert the former one here and improve documentation in
the next patch.

Fixes: d5dcce0c414f ("device property: Keep secondary firmware node secondary by type")
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
---
 drivers/base/core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 25e08e5f40bd..51b9545a050b 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -4433,7 +4433,7 @@ void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
 		if (fwnode_is_primary(fn)) {
 			dev->fwnode = fn->secondary;
 			if (!(parent && fn == parent->fwnode))
-				fn->secondary = ERR_PTR(-ENODEV);
+				fn->secondary = NULL;
 		} else {
 			dev->fwnode = NULL;
 		}
-- 
2.17.1

[PATCH 2/2] device property: add description of fwnode cases

[Bard Liao]

There are only four valid fwnode cases which are
- primary --> secondary --> -ENODEV
- primary --> NULL
- secondary --> -ENODEV
- NULL

dev->fwnode should be converted between the 4 cases above no matter
how/when set_primary_fwnode() and set_secondary_fwnode() are called.
Describe it in the code so people will keep it in mind.

Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
---
 drivers/base/core.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 51b9545a050b..17eb14607074 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -4414,6 +4414,12 @@ static inline bool fwnode_is_primary(struct fwnode_handle *fwnode)
  *
  * Set the device's firmware node pointer to @fwnode, but if a secondary
  * firmware node of the device is present, preserve it.
+ *
+ * Valid fwnode cases are:
+ *  - primary --> secondary --> -ENODEV
+ *  - primary --> NULL
+ *  - secondary --> -ENODEV
+ *  - NULL
  */
 void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
 {
@@ -4432,6 +4438,7 @@ void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
 	} else {
 		if (fwnode_is_primary(fn)) {
 			dev->fwnode = fn->secondary;
+			/* Set fn->secondary = NULL to keep fn as a primary fwnode */
 			if (!(parent && fn == parent->fwnode))
 				fn->secondary = NULL;
 		} else {
-- 
2.17.1

Re: [PATCH 1/2] Revert "device property: Keep secondary firmware node secondary by type"

[Andy Shevchenko]

On Tue, Jan 05, 2021 at 05:11:45PM +0800, Bard Liao wrote:
> While the commit d5dcce0c414f ("device property: Keep secondary firmware
> node secondary by type")
> describes everything correct in its commit message the change it made does
> the opposite and original commit c15e1bdda436 ("device property: Fix the
> secondary firmware node handling in set_primary_fwnode()") was fully
> correct. Thus, revert the former one here and improve documentation in
> the next patch.

Thanks for catching this!
Yes, my bad that I have misinterpreted Heikki's idea.
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

> Fixes: d5dcce0c414f ("device property: Keep secondary firmware node secondary by type")
> Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
> ---
>  drivers/base/core.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/base/core.c b/drivers/base/core.c
> index 25e08e5f40bd..51b9545a050b 100644
> --- a/drivers/base/core.c
> +++ b/drivers/base/core.c
> @@ -4433,7 +4433,7 @@ void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
>  		if (fwnode_is_primary(fn)) {
>  			dev->fwnode = fn->secondary;
>  			if (!(parent && fn == parent->fwnode))
> -				fn->secondary = ERR_PTR(-ENODEV);
> +				fn->secondary = NULL;
>  		} else {
>  			dev->fwnode = NULL;
>  		}
> -- 
> 2.17.1
> 

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH 2/2] device property: add description of fwnode cases

[Andy Shevchenko]

On Tue, Jan 05, 2021 at 05:11:46PM +0800, Bard Liao wrote:
> There are only four valid fwnode cases which are
> - primary --> secondary --> -ENODEV
> - primary --> NULL
> - secondary --> -ENODEV
> - NULL
> 
> dev->fwnode should be converted between the 4 cases above no matter
> how/when set_primary_fwnode() and set_secondary_fwnode() are called.
> Describe it in the code so people will keep it in mind.

Thanks! It will help in the future to understand better this code.
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

> Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
> ---
>  drivers/base/core.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/drivers/base/core.c b/drivers/base/core.c
> index 51b9545a050b..17eb14607074 100644
> --- a/drivers/base/core.c
> +++ b/drivers/base/core.c
> @@ -4414,6 +4414,12 @@ static inline bool fwnode_is_primary(struct fwnode_handle *fwnode)
>   *
>   * Set the device's firmware node pointer to @fwnode, but if a secondary
>   * firmware node of the device is present, preserve it.
> + *
> + * Valid fwnode cases are:
> + *  - primary --> secondary --> -ENODEV
> + *  - primary --> NULL
> + *  - secondary --> -ENODEV
> + *  - NULL
>   */
>  void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
>  {
> @@ -4432,6 +4438,7 @@ void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
>  	} else {
>  		if (fwnode_is_primary(fn)) {
>  			dev->fwnode = fn->secondary;
> +			/* Set fn->secondary = NULL to keep fn as a primary fwnode */
>  			if (!(parent && fn == parent->fwnode))
>  				fn->secondary = NULL;
>  		} else {
> -- 
> 2.17.1
> 

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH 1/2] Revert "device property: Keep secondary firmware node secondary by type"

[Heikki Krogerus]

On Tue, Jan 05, 2021 at 05:11:45PM +0800, Bard Liao wrote:
> While the commit d5dcce0c414f ("device property: Keep secondary firmware
> node secondary by type")
> describes everything correct in its commit message the change it made does
> the opposite and original commit c15e1bdda436 ("device property: Fix the
> secondary firmware node handling in set_primary_fwnode()") was fully
> correct. Thus, revert the former one here and improve documentation in
> the next patch.
> 
> Fixes: d5dcce0c414f ("device property: Keep secondary firmware node secondary by type")
> Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>

FWIW:

Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>

> ---
>  drivers/base/core.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/base/core.c b/drivers/base/core.c
> index 25e08e5f40bd..51b9545a050b 100644
> --- a/drivers/base/core.c
> +++ b/drivers/base/core.c
> @@ -4433,7 +4433,7 @@ void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
>  		if (fwnode_is_primary(fn)) {
>  			dev->fwnode = fn->secondary;
>  			if (!(parent && fn == parent->fwnode))
> -				fn->secondary = ERR_PTR(-ENODEV);
> +				fn->secondary = NULL;
>  		} else {
>  			dev->fwnode = NULL;
>  		}
> -- 
> 2.17.1

-- 
heikki

Re: [PATCH 2/2] device property: add description of fwnode cases

[Heikki Krogerus]

On Tue, Jan 05, 2021 at 05:11:46PM +0800, Bard Liao wrote:
> There are only four valid fwnode cases which are
> - primary --> secondary --> -ENODEV
> - primary --> NULL
> - secondary --> -ENODEV
> - NULL
> 
> dev->fwnode should be converted between the 4 cases above no matter
> how/when set_primary_fwnode() and set_secondary_fwnode() are called.
> Describe it in the code so people will keep it in mind.
> 
> Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>

Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>

> ---
>  drivers/base/core.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/drivers/base/core.c b/drivers/base/core.c
> index 51b9545a050b..17eb14607074 100644
> --- a/drivers/base/core.c
> +++ b/drivers/base/core.c
> @@ -4414,6 +4414,12 @@ static inline bool fwnode_is_primary(struct fwnode_handle *fwnode)
>   *
>   * Set the device's firmware node pointer to @fwnode, but if a secondary
>   * firmware node of the device is present, preserve it.
> + *
> + * Valid fwnode cases are:
> + *  - primary --> secondary --> -ENODEV
> + *  - primary --> NULL
> + *  - secondary --> -ENODEV
> + *  - NULL
>   */
>  void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
>  {
> @@ -4432,6 +4438,7 @@ void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
>  	} else {
>  		if (fwnode_is_primary(fn)) {
>  			dev->fwnode = fn->secondary;
> +			/* Set fn->secondary = NULL to keep fn as a primary fwnode */
>  			if (!(parent && fn == parent->fwnode))
>  				fn->secondary = NULL;
>  		} else {
> -- 
> 2.17.1

thanks,

-- 
heikki

Re: [PATCH 2/2] device property: add description of fwnode cases

[Rafael J. Wysocki]

On Thu, Jan 7, 2021 at 3:11 PM Heikki Krogerus
<heikki.krogerus@linux.intel.com> wrote:
>
> On Tue, Jan 05, 2021 at 05:11:46PM +0800, Bard Liao wrote:
> > There are only four valid fwnode cases which are
> > - primary --> secondary --> -ENODEV
> > - primary --> NULL
> > - secondary --> -ENODEV
> > - NULL
> >
> > dev->fwnode should be converted between the 4 cases above no matter
> > how/when set_primary_fwnode() and set_secondary_fwnode() are called.
> > Describe it in the code so people will keep it in mind.
> >
> > Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
>
> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
>
> > ---
> >  drivers/base/core.c | 7 +++++++
> >  1 file changed, 7 insertions(+)
> >
> > diff --git a/drivers/base/core.c b/drivers/base/core.c
> > index 51b9545a050b..17eb14607074 100644
> > --- a/drivers/base/core.c
> > +++ b/drivers/base/core.c
> > @@ -4414,6 +4414,12 @@ static inline bool fwnode_is_primary(struct fwnode_handle *fwnode)
> >   *
> >   * Set the device's firmware node pointer to @fwnode, but if a secondary
> >   * firmware node of the device is present, preserve it.
> > + *
> > + * Valid fwnode cases are:
> > + *  - primary --> secondary --> -ENODEV
> > + *  - primary --> NULL
> > + *  - secondary --> -ENODEV
> > + *  - NULL
> >   */
> >  void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
> >  {
> > @@ -4432,6 +4438,7 @@ void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
> >       } else {
> >               if (fwnode_is_primary(fn)) {
> >                       dev->fwnode = fn->secondary;
> > +                     /* Set fn->secondary = NULL to keep fn as a primary fwnode */
> >                       if (!(parent && fn == parent->fwnode))
> >                               fn->secondary = NULL;
> >               } else {
> > --

Applied (with a minor edit in the new comment) along with the [1/2] as
5.11-rc material, thanks!