[PATCH v2 0/6] Stop NULLifying match pointer in of_match_device()

[PATCH v2 0/6] Stop NULLifying match pointer in of_match_device()

[Stephen Boyd]

(This is a continuation of this series[1] per Rob's request. I've picked
up the acks, etc. with b4 and compile tested the patches along with an
arm64 allmodconfig build. Presumably Rob will pick these up directly.)

of_match_device() uses of_match_ptr() to make the match table argument
NULL via the pre-processor when CONFIG_OF=n. This makes life harder for
compilers who think that match tables are never used and warn about
unused variables when CONFIG_OF=n. This series changes various callers
to use of_device_get_match_data() instead, which doesn't have this
problem, and removes the of_match_ptr() usage from of_match_device() so
that the compiler can stop complaining about unused variables. It will
do dead code elimination instead and remove the match table if it isn't
actually used.

[1] https://lore.kernel.org/r/20191004214334.149976-1-swboyd@chromium.org

Cc: Alexandre Torgue <alexandre.torgue@st.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Jacopo Mondi <jacopo@jmondi.org>
Cc: Jean Delvare <jdelvare@suse.com>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: <linux-hwmon@vger.kernel.org>
Cc: <linux-kernel@vger.kernel.org>,
Cc: <linux-media@vger.kernel.org>
Cc: <linux-omap@vger.kernel.org>
Cc: <linux-renesas-soc@vger.kernel.org>
Cc: <linux-serial@vger.kernel.org>
Cc: <linux-usb@vger.kernel.org>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Richard Leitner <richard.leitner@skidata.com>
Cc: Rob Herring <robh+dt@kernel.org>

Stephen Boyd (6):
  media: renesas-ceu: Use of_device_get_match_data()
  drivers: net: davinci_mdio: Use of_device_get_match_data()
  serial: stm32: Use of_device_get_match_data()
  usb: usb251xb: Use of_device_get_match_data()
  hwmon: (lm70) Avoid undefined reference to match table
  of/device: Don't NULLify match table in of_match_device() with
    CONFIG_OF=n

 drivers/hwmon/lm70.c                   |  2 +-
 drivers/media/platform/renesas-ceu.c   |  2 +-
 drivers/net/ethernet/ti/davinci_mdio.c | 12 ++---
 drivers/tty/serial/stm32-usart.c       | 71 ++++++++++++--------------
 drivers/tty/serial/stm32-usart.h       |  2 +-
 drivers/usb/misc/usb251xb.c            | 12 ++---
 include/linux/of_device.h              |  4 +-
 7 files changed, 47 insertions(+), 58 deletions(-)


base-commit: 19c329f6808995b142b3966301f217c831e7cf31
-- 
https://chromeos.dev

[PATCH v2 5/6] hwmon: (lm70) Avoid undefined reference to match table

[Stephen Boyd]

We're going to remove of_match_ptr() from the definition of
of_match_device() when CONFIG_OF=n. This way we can always be certain
that of_match_device() acts the same when CONFIG_OF is set and when it
isn't. Add of_match_ptr() here so that this doesn't break when that
change is made to the of_match_device() API.

Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Jean Delvare <jdelvare@suse.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: <linux-hwmon@vger.kernel.org>
---

Please ack so Rob can apply.

 drivers/hwmon/lm70.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/hwmon/lm70.c b/drivers/hwmon/lm70.c
index ae2b84263a44..e3153ae80634 100644
--- a/drivers/hwmon/lm70.c
+++ b/drivers/hwmon/lm70.c
@@ -178,7 +178,7 @@ static int lm70_probe(struct spi_device *spi)
 	struct lm70 *p_lm70;
 	int chip;
 
-	of_match = of_match_device(lm70_of_ids, &spi->dev);
+	of_match = of_match_device(of_match_ptr(lm70_of_ids), &spi->dev);
 	if (of_match)
 		chip = (int)(uintptr_t)of_match->data;
 	else {
-- 
https://chromeos.dev

Re: [PATCH v2 5/6] hwmon: (lm70) Avoid undefined reference to match table

[Guenter Roeck]

On 1/22/21 7:44 PM, Stephen Boyd wrote:
> We're going to remove of_match_ptr() from the definition of
> of_match_device() when CONFIG_OF=n. This way we can always be certain
> that of_match_device() acts the same when CONFIG_OF is set and when it
> isn't. Add of_match_ptr() here so that this doesn't break when that
> change is made to the of_match_device() API.
> 
> Signed-off-by: Stephen Boyd <swboyd@chromium.org>
> Acked-by: Guenter Roeck <linux@roeck-us.net>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Geert Uytterhoeven <geert@linux-m68k.org>
> Cc: Jean Delvare <jdelvare@suse.com>
> Cc: Guenter Roeck <linux@roeck-us.net>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: Frank Rowand <frowand.list@gmail.com>
> Cc: <linux-hwmon@vger.kernel.org>
> ---
> 
> Please ack so Rob can apply.
> 

This patch already has my Acked-by: above.

Guenter

>  drivers/hwmon/lm70.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/hwmon/lm70.c b/drivers/hwmon/lm70.c
> index ae2b84263a44..e3153ae80634 100644
> --- a/drivers/hwmon/lm70.c
> +++ b/drivers/hwmon/lm70.c
> @@ -178,7 +178,7 @@ static int lm70_probe(struct spi_device *spi)
>  	struct lm70 *p_lm70;
>  	int chip;
>  
> -	of_match = of_match_device(lm70_of_ids, &spi->dev);
> +	of_match = of_match_device(of_match_ptr(lm70_of_ids), &spi->dev);
>  	if (of_match)
>  		chip = (int)(uintptr_t)of_match->data;
>  	else {
> 

Re: [PATCH v2 0/6] Stop NULLifying match pointer in of_match_device()

[Rob Herring]

On Fri, Jan 22, 2021 at 9:44 PM Stephen Boyd <swboyd@chromium.org> wrote:
>
> (This is a continuation of this series[1] per Rob's request. I've picked
> up the acks, etc. with b4 and compile tested the patches along with an
> arm64 allmodconfig build. Presumably Rob will pick these up directly.)
>
> of_match_device() uses of_match_ptr() to make the match table argument
> NULL via the pre-processor when CONFIG_OF=n. This makes life harder for
> compilers who think that match tables are never used and warn about
> unused variables when CONFIG_OF=n. This series changes various callers
> to use of_device_get_match_data() instead, which doesn't have this
> problem, and removes the of_match_ptr() usage from of_match_device() so
> that the compiler can stop complaining about unused variables. It will
> do dead code elimination instead and remove the match table if it isn't
> actually used.
>
> [1] https://lore.kernel.org/r/20191004214334.149976-1-swboyd@chromium.org
>
> Cc: Alexandre Torgue <alexandre.torgue@st.com>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Frank Rowand <frowand.list@gmail.com>
> Cc: Geert Uytterhoeven <geert@linux-m68k.org>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: Grygorii Strashko <grygorii.strashko@ti.com>
> Cc: Guenter Roeck <linux@roeck-us.net>
> Cc: Jacopo Mondi <jacopo@jmondi.org>
> Cc: Jean Delvare <jdelvare@suse.com>
> Cc: Jiri Slaby <jslaby@suse.com>
> Cc: <linux-hwmon@vger.kernel.org>
> Cc: <linux-kernel@vger.kernel.org>,
> Cc: <linux-media@vger.kernel.org>
> Cc: <linux-omap@vger.kernel.org>
> Cc: <linux-renesas-soc@vger.kernel.org>
> Cc: <linux-serial@vger.kernel.org>
> Cc: <linux-usb@vger.kernel.org>
> Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
> Cc: Richard Leitner <richard.leitner@skidata.com>
> Cc: Rob Herring <robh+dt@kernel.org>
>
> Stephen Boyd (6):
>   media: renesas-ceu: Use of_device_get_match_data()
>   drivers: net: davinci_mdio: Use of_device_get_match_data()
>   serial: stm32: Use of_device_get_match_data()
>   usb: usb251xb: Use of_device_get_match_data()
>   hwmon: (lm70) Avoid undefined reference to match table
>   of/device: Don't NULLify match table in of_match_device() with
>     CONFIG_OF=n
>
>  drivers/hwmon/lm70.c                   |  2 +-
>  drivers/media/platform/renesas-ceu.c   |  2 +-
>  drivers/net/ethernet/ti/davinci_mdio.c | 12 ++---
>  drivers/tty/serial/stm32-usart.c       | 71 ++++++++++++--------------
>  drivers/tty/serial/stm32-usart.h       |  2 +-
>  drivers/usb/misc/usb251xb.c            | 12 ++---
>  include/linux/of_device.h              |  4 +-
>  7 files changed, 47 insertions(+), 58 deletions(-)

Series applied.


Rob

Re: [PATCH v2 5/6] hwmon: (lm70) Avoid undefined reference to match table

[Rob Herring]

On Fri, Jan 22, 2021 at 9:44 PM Stephen Boyd <swboyd@chromium.org> wrote:
>
> We're going to remove of_match_ptr() from the definition of
> of_match_device() when CONFIG_OF=n. This way we can always be certain
> that of_match_device() acts the same when CONFIG_OF is set and when it
> isn't. Add of_match_ptr() here so that this doesn't break when that
> change is made to the of_match_device() API.
>
> Signed-off-by: Stephen Boyd <swboyd@chromium.org>
> Acked-by: Guenter Roeck <linux@roeck-us.net>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Geert Uytterhoeven <geert@linux-m68k.org>
> Cc: Jean Delvare <jdelvare@suse.com>
> Cc: Guenter Roeck <linux@roeck-us.net>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: Frank Rowand <frowand.list@gmail.com>
> Cc: <linux-hwmon@vger.kernel.org>
> ---
>
> Please ack so Rob can apply.
>
>  drivers/hwmon/lm70.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/hwmon/lm70.c b/drivers/hwmon/lm70.c
> index ae2b84263a44..e3153ae80634 100644
> --- a/drivers/hwmon/lm70.c
> +++ b/drivers/hwmon/lm70.c
> @@ -178,7 +178,7 @@ static int lm70_probe(struct spi_device *spi)
>         struct lm70 *p_lm70;
>         int chip;
>
> -       of_match = of_match_device(lm70_of_ids, &spi->dev);
> +       of_match = of_match_device(of_match_ptr(lm70_of_ids), &spi->dev);
>         if (of_match)
>                 chip = (int)(uintptr_t)of_match->data;

Why can't this do:

if (spi->dev.of_node)
    chip = (int)(uintptr_t)of_device_get_match_data();
else {

>         else {
> --
> https://chromeos.dev
>