[PATCH 0/2] Support reboot power-off driver as module

[PATCH 0/2] Support reboot power-off driver as module

[Elliot Berman]

This series supports reboot power-off driver as a module by exporting
reboot_mode symbol.

Elliot Berman (2):
  reboot: Export reboot_mode
  power: reset: Enable tristate on restart power-off driver

 drivers/power/reset/Kconfig | 2 +-
 kernel/reboot.c             | 2 ++
 2 files changed, 3 insertions(+), 1 deletion(-)

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[PATCH 1/2] reboot: Export reboot_mode

[Elliot Berman]

Export reboot_mode to support DLKMs wishing to modify reboot_mode.

Signed-off-by: Elliot Berman <eberman@codeaurora.org>
---
 kernel/reboot.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/kernel/reboot.c b/kernel/reboot.c
index c4d472b..6518370 100644
--- a/kernel/reboot.c
+++ b/kernel/reboot.c
@@ -32,7 +32,9 @@ EXPORT_SYMBOL(cad_pid);
 #define DEFAULT_REBOOT_MODE
 #endif
 enum reboot_mode reboot_mode DEFAULT_REBOOT_MODE;
+EXPORT_SYMBOL(reboot_mode);
 enum reboot_mode panic_reboot_mode = REBOOT_UNDEFINED;
+EXPORT_SYMBOL(panic_reboot_mode);
 
 /*
  * This variable is used privately to keep track of whether or not
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

Re: [PATCH 1/2] reboot: Export reboot_mode

[Greg KH]

On Fri, Nov 08, 2019 at 11:32:11AM -0800, Elliot Berman wrote:
> Export reboot_mode to support DLKMs wishing to modify reboot_mode.

"DLKMs"?  What's that?

A kernel module?

> 
> Signed-off-by: Elliot Berman <eberman@codeaurora.org>
> ---
>  kernel/reboot.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/kernel/reboot.c b/kernel/reboot.c
> index c4d472b..6518370 100644
> --- a/kernel/reboot.c
> +++ b/kernel/reboot.c
> @@ -32,7 +32,9 @@ EXPORT_SYMBOL(cad_pid);
>  #define DEFAULT_REBOOT_MODE
>  #endif
>  enum reboot_mode reboot_mode DEFAULT_REBOOT_MODE;
> +EXPORT_SYMBOL(reboot_mode);
>  enum reboot_mode panic_reboot_mode = REBOOT_UNDEFINED;
> +EXPORT_SYMBOL(panic_reboot_mode);

EXPORT_SYMBOL_GPL() perhaps?

thanks,

greg k-h

Re: [PATCH 1/2] reboot: Export reboot_mode

[Christoph Hellwig]

On Fri, Nov 08, 2019 at 08:39:58PM +0100, Greg KH wrote:
> > diff --git a/kernel/reboot.c b/kernel/reboot.c
> > index c4d472b..6518370 100644
> > --- a/kernel/reboot.c
> > +++ b/kernel/reboot.c
> > @@ -32,7 +32,9 @@ EXPORT_SYMBOL(cad_pid);
> >  #define DEFAULT_REBOOT_MODE
> >  #endif
> >  enum reboot_mode reboot_mode DEFAULT_REBOOT_MODE;
> > +EXPORT_SYMBOL(reboot_mode);
> >  enum reboot_mode panic_reboot_mode = REBOOT_UNDEFINED;
> > +EXPORT_SYMBOL(panic_reboot_mode);
> 
> EXPORT_SYMBOL_GPL() perhaps?

Absolutely.  But then again drivers/power/reset/reboot-mode.c, which
he wants to make modular in patch 2 is just a trivial abstraction
that avoids drivers directly poking into these values.  I really don't
see a point to make that modular to start with.

[PATCH 2/2] power: reset: Enable tristate on restart power-off driver

[Elliot Berman]

Since reboot_mode is an exported symbol, restart power-off driver can be
compiled as module.

Signed-off-by: Elliot Berman <eberman@codeaurora.org>
---
 drivers/power/reset/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
index a564237..8db1d9d 100644
--- a/drivers/power/reset/Kconfig
+++ b/drivers/power/reset/Kconfig
@@ -150,7 +150,7 @@ config POWER_RESET_QNAP
 	  Say Y if you have a QNAP NAS.
 
 config POWER_RESET_RESTART
-	bool "Restart power-off driver"
+	tristate "Restart power-off driver"
 	help
 	  Some boards don't actually have the ability to power off.
 	  Instead they restart, and u-boot holds the SoC until the
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