[01/12] net: dsa: lantiq_gswip: mark OF related data as maybe unused

  The driver can be compile tested with !CONFIG_OF making certain data
unused:

  drivers/net/dsa/lantiq_gswip.c:1888:34: error: ‘xway_gphy_match’ defined but not used [-Werror=unused-const-variable=]

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
---
 drivers/net/dsa/lantiq_gswip.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
  

On Sat, Mar 11, 2023 at 06:32:52PM +0100, Krzysztof Kozlowski wrote:
> The driver can be compile tested with !CONFIG_OF making certain data
> unused:
> 
>   drivers/net/dsa/lantiq_gswip.c:1888:34: error: ‘xway_gphy_match’ defined but not used [-Werror=unused-const-variable=]
> 
> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> ---

Do you happen to have any context as to why of_match_node() without
CONFIG_OF is implemented as:

#define of_match_node(_matches, _node)	NULL

and not as:

static inline const struct of_device_id *
of_match_node(const struct of_device_id *matches,
	      const struct device_node *node)
{
	return NULL;
}

?

Generally, the static inline shim function model is nicer, because it
allows us to not scatter __maybe_unused all around.
  

On 11/03/2023 19:14, Vladimir Oltean wrote:
> On Sat, Mar 11, 2023 at 06:32:52PM +0100, Krzysztof Kozlowski wrote:
>> The driver can be compile tested with !CONFIG_OF making certain data
>> unused:
>>
>>   drivers/net/dsa/lantiq_gswip.c:1888:34: error: ‘xway_gphy_match’ defined but not used [-Werror=unused-const-variable=]
>>
>> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
>> ---
> 
> Do you happen to have any context as to why of_match_node() without
> CONFIG_OF is implemented as:
> 
> #define of_match_node(_matches, _node)	NULL
> 
> and not as:
> 
> static inline const struct of_device_id *
> of_match_node(const struct of_device_id *matches,
> 	      const struct device_node *node)
> {
> 	return NULL;
> }
> 
> ?
> 
> Generally, the static inline shim function model is nicer, because it
> allows us to not scatter __maybe_unused all around.

Sorry, I don't follow. I don't touch that wrappers, just fix errors
related to OF device ID tables, although in few cases it is indeed
related to of_match_node.

Best regards,
Krzysztof
  

On Sun, Mar 12, 2023 at 11:20:38AM +0100, Krzysztof Kozlowski wrote:
> On 11/03/2023 19:14, Vladimir Oltean wrote:
> > On Sat, Mar 11, 2023 at 06:32:52PM +0100, Krzysztof Kozlowski wrote:
> >> The driver can be compile tested with !CONFIG_OF making certain data
> >> unused:
> >>
> >>   drivers/net/dsa/lantiq_gswip.c:1888:34: error: ‘xway_gphy_match’ defined but not used [-Werror=unused-const-variable=]
> >>
> >> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> >> ---
> > 
> > Do you happen to have any context as to why of_match_node() without
> > CONFIG_OF is implemented as:
> > 
> > #define of_match_node(_matches, _node)	NULL
> > 
> > and not as:
> > 
> > static inline const struct of_device_id *
> > of_match_node(const struct of_device_id *matches,
> > 	      const struct device_node *node)
> > {
> > 	return NULL;
> > }
> > 
> > ?
> > 
> > Generally, the static inline shim function model is nicer, because it
> > allows us to not scatter __maybe_unused all around.
> 
> Sorry, I don't follow. I don't touch that wrappers, just fix errors
> related to OF device ID tables, although in few cases it is indeed
> related to of_match_node.

I'm saying this because in lantiq_gswip.c, xway_gphy_match is accessed
through of_match_node(). If the shim definition for of_match_node() was
different, the variable wouldn't have been unused with CONFIG_OF=n.
I guess it's worth considering changing that wrapper instead of adding
the __maybe_unused.
  

On Sun, 12 Mar 2023 12:57:29 +0200 Vladimir Oltean wrote:
> > Sorry, I don't follow. I don't touch that wrappers, just fix errors
> > related to OF device ID tables, although in few cases it is indeed
> > related to of_match_node.  
> 
> I'm saying this because in lantiq_gswip.c, xway_gphy_match is accessed
> through of_match_node(). If the shim definition for of_match_node() was
> different, the variable wouldn't have been unused with CONFIG_OF=n.
> I guess it's worth considering changing that wrapper instead of adding
> the __maybe_unused.

Hi Krzysztof, have you had a chance to check if using an empty static
inline is enough to silence the compiler? Seems like it could save
us quite some churn? Or do we want the of_match_node() decorations
to go away in general?
  

Hello:

This series was applied to netdev/net-next.git (main)
by David S. Miller <davem@davemloft.net>:

On Sat, 11 Mar 2023 18:32:52 +0100 you wrote:
> The driver can be compile tested with !CONFIG_OF making certain data
> unused:
> 
>   drivers/net/dsa/lantiq_gswip.c:1888:34: error: ‘xway_gphy_match’ defined but not used [-Werror=unused-const-variable=]
> 
> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> 
> [...]

Here is the summary with links:
  - [01/12] net: dsa: lantiq_gswip: mark OF related data as maybe unused
    https://git.kernel.org/netdev/net-next/c/6ea1e67788f3
  - [02/12] net: dsa: lan9303: drop of_match_ptr for ID table
    https://git.kernel.org/netdev/net-next/c/ced5c5a0a2ea
  - [03/12] net: dsa: seville_vsc9953: drop of_match_ptr for ID table
    https://git.kernel.org/netdev/net-next/c/1eb8566dd08d
  - [04/12] net: dsa: ksz9477: drop of_match_ptr for ID table
    https://git.kernel.org/netdev/net-next/c/00923ff2e1ba
  - [05/12] net: dsa: ocelot: drop of_match_ptr for ID table
    https://git.kernel.org/netdev/net-next/c/0f17b42827ae
  - [06/12] net: phy: ks8995: drop of_match_ptr for ID table
    https://git.kernel.org/netdev/net-next/c/b0b7d1b6260b
  - [07/12] net: ieee802154: adf7242: drop of_match_ptr for ID table
    https://git.kernel.org/netdev/net-next/c/3df09beef650
  - [08/12] net: ieee802154: mcr20a: drop of_match_ptr for ID table
    https://git.kernel.org/netdev/net-next/c/3896c40b7824
  - [09/12] net: ieee802154: at86rf230: drop of_match_ptr for ID table
    https://git.kernel.org/netdev/net-next/c/32b7030681a4
  - [10/12] net: ieee802154: ca8210: drop of_match_ptr for ID table
    https://git.kernel.org/netdev/net-next/c/cdfe4fc4d946
  - [11/12] net: ieee802154: adf7242: drop owner from driver
    https://git.kernel.org/netdev/net-next/c/059fa9972340
  - [12/12] net: ieee802154: ca8210: drop owner from driver
    https://git.kernel.org/netdev/net-next/c/613a3c44a373

You are awesome, thank you!
  

On Wed, 15 Mar 2023 08:20:20 +0000 patchwork-bot+netdevbpf@kernel.org
wrote:
> This series was applied to netdev/net-next.git (main)
> by David S. Miller <davem@davemloft.net>:

:) :) :)
  

On 15/03/2023 06:22, Jakub Kicinski wrote:
> On Sun, 12 Mar 2023 12:57:29 +0200 Vladimir Oltean wrote:
>>> Sorry, I don't follow. I don't touch that wrappers, just fix errors
>>> related to OF device ID tables, although in few cases it is indeed
>>> related to of_match_node.  
>>
>> I'm saying this because in lantiq_gswip.c, xway_gphy_match is accessed
>> through of_match_node(). If the shim definition for of_match_node() was
>> different, the variable wouldn't have been unused with CONFIG_OF=n.
>> I guess it's worth considering changing that wrapper instead of adding
>> the __maybe_unused.
> 
> Hi Krzysztof, have you had a chance to check if using an empty static
> inline is enough to silence the compiler? Seems like it could save
> us quite some churn? Or do we want the of_match_node() decorations
> to go away in general?

I am pretty sure fixing of_match_node() and of_match_ptr() (independent
case) would supersed this patchset, but it is a bit bigger change than I
have available time now.  I didn't try it yet.


Best regards,
Krzysztof