Re: [PATCH 01/27] driver core: Constify driver API device_find_child()

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Tue, Aug 13, 2024 at 06:39:48PM +0800, quic_zijuhu wrote:
> On 8/13/2024 5:48 PM, Greg Kroah-Hartman wrote:
> > On Sun, Aug 11, 2024 at 10:24:52AM +0800, Zijun Hu wrote:
> >> From: Zijun Hu <quic_zijuhu@quicinc.com>
> >>
> >> Constify the following driver API:
> >> struct device *device_find_child(struct device *dev, void *data,
> >> 		int (*match)(struct device *dev, void *data));
> >> to
> >> struct device *device_find_child(struct device *dev, const void *data,
> >>                                  device_match_t match);
> >> typedef int (*device_match_t)(struct device *dev, const void *data);
> >> Since it should not modify caller's match data @*data.
> >>
> >> Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
> >> ---
> >>  drivers/base/core.c    | 11 +++--------
> >>  include/linux/device.h |  4 ++--
> >>  2 files changed, 5 insertions(+), 10 deletions(-)
> >>
> >> diff --git a/drivers/base/core.c b/drivers/base/core.c
> >> index 3f3ebdb5aa0b..f152e0f8fb03 100644
> >> --- a/drivers/base/core.c
> >> +++ b/drivers/base/core.c
> >> @@ -4062,8 +4062,8 @@ EXPORT_SYMBOL_GPL(device_for_each_child_reverse);
> >>   *
> >>   * NOTE: you will need to drop the reference with put_device() after use.
> >>   */
> >> -struct device *device_find_child(struct device *parent, void *data,
> >> -				 int (*match)(struct device *dev, void *data))
> >> +struct device *device_find_child(struct device *parent, const void *data,
> >> +				 device_match_t match)
> >>  {
> >>  	struct klist_iter i;
> >>  	struct device *child;
> >> @@ -4108,11 +4108,6 @@ struct device *device_find_child_by_name(struct device *parent,
> >>  }
> >>  EXPORT_SYMBOL_GPL(device_find_child_by_name);
> >>  
> >> -static int match_any(struct device *dev, void *unused)
> >> -{
> >> -	return 1;
> >> -}
> >> -
> >>  /**
> >>   * device_find_any_child - device iterator for locating a child device, if any.
> >>   * @parent: parent struct device
> >> @@ -4124,7 +4119,7 @@ static int match_any(struct device *dev, void *unused)
> >>   */
> >>  struct device *device_find_any_child(struct device *parent)
> >>  {
> >> -	return device_find_child(parent, NULL, match_any);
> >> +	return device_find_child(parent, NULL, device_match_any);
> >>  }
> >>  EXPORT_SYMBOL_GPL(device_find_any_child);
> >>  
> >> diff --git a/include/linux/device.h b/include/linux/device.h
> >> index b2423fca3d45..76f10bdbb4ea 100644
> >> --- a/include/linux/device.h
> >> +++ b/include/linux/device.h
> >> @@ -1073,8 +1073,8 @@ int device_for_each_child(struct device *dev, void *data,
> >>  			  int (*fn)(struct device *dev, void *data));
> >>  int device_for_each_child_reverse(struct device *dev, void *data,
> >>  				  int (*fn)(struct device *dev, void *data));
> >> -struct device *device_find_child(struct device *dev, void *data,
> >> -				 int (*match)(struct device *dev, void *data));
> >> +struct device *device_find_child(struct device *dev, const void *data,
> >> +				 device_match_t match);
> >>  struct device *device_find_child_by_name(struct device *parent,
> >>  					 const char *name);
> >>  struct device *device_find_any_child(struct device *parent);
> >>
> >> -- 
> >> 2.34.1
> >>
> > 
> > This patch breaks the build:
> > 
> > ./include/linux/device.h:1077:6: error: unknown type name 'device_match_t'
> >  1077 |                                  device_match_t match);
> >       |                                  ^
> > 1 error generated.
> > make[2]: *** [scripts/Makefile.build:117: arch/x86/kernel/asm-offsets.s] Error 1
> > make[1]: *** [/mnt/fast_t2/linux/work/driver-core/Makefile:1193: prepare0] Error 2
> > 
> > How did you test it?
> > 
> > And as you are changing the parameters here, doesn't the build break
> > also because of that?
> > 
> 
> it seems these dependency patches listed within [PATCH 00/27] are not
> picked up.

Of course not, please send stand-alone series if you need them to be
applied in a specific order.

thanks,

greg k-h