[PATCH] staging: rtl8723bs: define wowlan_stub only when CONFIG_PM is enabled

[PATCH] staging: rtl8723bs: define wowlan_stub only when CONFIG_PM is enabled

[Bryan Brattlof]

The wake-on-lan stub is needed only when the device power management
functionality is enabled in the kernel. Conditionally define
wowlan_stub to avoid potential unused object warnings.

Signed-off-by: Bryan Brattlof <hello@bryanbrattlof.com>
---
 drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c b/drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c
index 34da8a569709..f4a9b4b7c97e 100644
--- a/drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c
+++ b/drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c
@@ -47,6 +47,7 @@ static const u32 rtw_cipher_suites[] = {
  * Moreover wowlan has to be enabled via a the nl80211_set_wowlan callback.
  * (from user space, e.g. iw phy0 wowlan enable)
  */
+#if defined(CONFIG_PM)
 static const struct wiphy_wowlan_support wowlan_stub = {
 	.flags = WIPHY_WOWLAN_ANY,
 	.n_patterns = 0,
@@ -54,6 +55,7 @@ static const struct wiphy_wowlan_support wowlan_stub = {
 	.pattern_min_len = 0,
 	.max_pkt_offset = 0,
 };
+#endif

 static struct ieee80211_rate rtw_rates[] = {
 	RATETAB_ENT(10,  0x1,   0),
--
2.30.2

Re: [PATCH] staging: rtl8723bs: define wowlan_stub only when CONFIG_PM is enabled

[Greg Kroah-Hartman]

On Mon, Sep 13, 2021 at 02:10:12PM +0000, Bryan Brattlof wrote:
> The wake-on-lan stub is needed only when the device power management
> functionality is enabled in the kernel. Conditionally define
> wowlan_stub to avoid potential unused object warnings.
> 
> Signed-off-by: Bryan Brattlof <hello@bryanbrattlof.com>
> ---
>  drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c b/drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c
> index 34da8a569709..f4a9b4b7c97e 100644
> --- a/drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c
> +++ b/drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c
> @@ -47,6 +47,7 @@ static const u32 rtw_cipher_suites[] = {
>   * Moreover wowlan has to be enabled via a the nl80211_set_wowlan callback.
>   * (from user space, e.g. iw phy0 wowlan enable)
>   */
> +#if defined(CONFIG_PM)
>  static const struct wiphy_wowlan_support wowlan_stub = {
>  	.flags = WIPHY_WOWLAN_ANY,
>  	.n_patterns = 0,
> @@ -54,6 +55,7 @@ static const struct wiphy_wowlan_support wowlan_stub = {
>  	.pattern_min_len = 0,
>  	.max_pkt_offset = 0,
>  };
> +#endif
> 
>  static struct ieee80211_rate rtw_rates[] = {
>  	RATETAB_ENT(10,  0x1,   0),
> --
> 2.30.2
> 
> 

Do you get a build warning with the code as-is?

Having #if in .c files is generally a bad idea, are you sure there is no
other way to solve this?

thanks,

greg k-h

Re: [PATCH] staging: rtl8723bs: define wowlan_stub only when CONFIG_PM is enabled

[Bryan Brattlof]

On this day, September 13, 2021, thus sayeth Greg Kroah-Hartman:
> On Mon, Sep 13, 2021 at 02:10:12PM +0000, Bryan Brattlof wrote:
> > The wake-on-lan stub is needed only when the device power management
> > functionality is enabled in the kernel. Conditionally define
> > wowlan_stub to avoid potential unused object warnings.
> >
> > Signed-off-by: Bryan Brattlof <hello@bryanbrattlof.com>
> > ---
> >  drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c | 2 ++
> >  1 file changed, 2 insertions(+)
> >
> > diff --git a/drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c b/drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c
> > index 34da8a569709..f4a9b4b7c97e 100644
> > --- a/drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c
> > +++ b/drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c
> > @@ -47,6 +47,7 @@ static const u32 rtw_cipher_suites[] = {
> >   * Moreover wowlan has to be enabled via a the nl80211_set_wowlan callback.
> >   * (from user space, e.g. iw phy0 wowlan enable)
> >   */
> > +#if defined(CONFIG_PM)
> >  static const struct wiphy_wowlan_support wowlan_stub = {
> >  	.flags = WIPHY_WOWLAN_ANY,
> >  	.n_patterns = 0,
> > @@ -54,6 +55,7 @@ static const struct wiphy_wowlan_support wowlan_stub = {
> >  	.pattern_min_len = 0,
> >  	.max_pkt_offset = 0,
> >  };
> > +#endif
> >
> >  static struct ieee80211_rate rtw_rates[] = {
> >  	RATETAB_ENT(10,  0x1,   0),
> > --
> > 2.30.2
> >
> >
>
> Do you get a build warning with the code as-is?
>
> Having #if in .c files is generally a bad idea, are you sure there is no
> other way to solve this?
>

Hi Greg,

Turns out I should have played with the CONFIG_PM setting more before I
sent you this patch. All of this can be ripped out.  :)

This is the warning I get with staging-next being where it is now:

  CC [M]  drivers/staging/rtl8723bs/os_dep/xmit_linux.o
drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c:50:42: warning: ‘wowlan_stub’ defined but not used [-Wunused-const-variable=]
   50 | static const struct wiphy_wowlan_support wowlan_stub = {
      |                                          ^~~~~~~~~~~

I'm using tinyconfig plus the rtl8723bs driver and it's dependencies to
build a microscopic buildroot image for an Intel Compute Stick I managed
to get my hands on recently.

I assumed disabling the power management parts of the kernel produced it
and didn't think twice. :/

I'll be back with a v2 that rips all of this out.

Thanks again Greg,
~Bryan

Re: [PATCH] staging: rtl8723bs: define wowlan_stub only when CONFIG_PM is enabled

[Dan Carpenter]

On Mon, Sep 13, 2021 at 11:42:55PM +0000, Bryan Brattlof wrote:
> I'll be back with a v2 that rips all of this out.

Or use the __maybe_unused annotation:

static __maybe_unused const struct wiphy_wowlan_support wowlan_stub = {

regards,
dan carpenter

Re: [PATCH] staging: rtl8723bs: define wowlan_stub only when CONFIG_PM is enabled

[Bryan Brattlof]

On this day, September 14, 2021, thus sayeth Dan Carpenter:
> On Mon, Sep 13, 2021 at 11:42:55PM +0000, Bryan Brattlof wrote:
> > I'll be back with a v2 that rips all of this out.
>
> Or use the __maybe_unused annotation:
>
> static __maybe_unused const struct wiphy_wowlan_support wowlan_stub = {
>

Thanks for the suggestion Dan; I like this much better. :)

I've been poking around with my config today and noticed I can still
produce this warning with CONFIG_PM enabled, which means something else
is going on that I don't fully understand yet.

I may hold off on sending v2 until I make sure I understand what's going
on and double check that I didn't bork my config.

Thanks from jumping in
~Bryan