* Re: [PATCH] b43: shut up clang -Wuninitialized variable warning
2019-03-22 14:37 [PATCH] b43: shut up clang -Wuninitialized variable warning Arnd Bergmann
@ 2019-03-22 15:47 ` Larry Finger
2019-03-22 16:06 ` Nathan Chancellor
2019-04-04 10:14 ` Kalle Valo
2 siblings, 0 replies; 4+ messages in thread
From: Larry Finger @ 2019-03-22 15:47 UTC (permalink / raw)
To: Arnd Bergmann, Kalle Valo, David S. Miller, Priit Laes
Cc: clang-built-linux, Nick Desaulniers, Nathan Chancellor,
linux-wireless, b43-dev, netdev, linux-kernel
On 3/22/19 9:37 AM, Arnd Bergmann wrote:
> Clang warns about what is clearly a case of passing an uninitalized
> variable into a static function:
>
> drivers/net/wireless/broadcom/b43/phy_lp.c:1852:23: error: variable 'gains' is uninitialized when used here
> [-Werror,-Wuninitialized]
> lpphy_papd_cal(dev, gains, 0, 1, 30);
> ^~~~~
> drivers/net/wireless/broadcom/b43/phy_lp.c:1838:2: note: variable 'gains' is declared here
> struct lpphy_tx_gains gains, oldgains;
> ^
> 1 error generated.
>
> However, this function is empty, and its arguments are never evaluated,
> so gcc in contrast does not warn here. Both compilers behave in a
> reasonable way as far as I can tell, so we should change the code
> to avoid the warning everywhere.
>
> We could just eliminate the lpphy_papd_cal() function entirely,
> given that it has had the TODO comment in it for 10 years now
> and is rather unlikely to ever get done. I'm doing a simpler
> change here, and just pass the 'oldgains' variable in that has
> been initialized, based on the guess that this is what was
> originally meant.
>
> Fixes: 2c0d6100da3e ("b43: LP-PHY: Begin implementing calibration & software RFKILL support")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
> drivers/net/wireless/broadcom/b43/phy_lp.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/net/wireless/broadcom/b43/phy_lp.c b/drivers/net/wireless/broadcom/b43/phy_lp.c
> index 46408a560814..aedee026c5e2 100644
> --- a/drivers/net/wireless/broadcom/b43/phy_lp.c
> +++ b/drivers/net/wireless/broadcom/b43/phy_lp.c
> @@ -1835,7 +1835,7 @@ static void lpphy_papd_cal(struct b43_wldev *dev, struct lpphy_tx_gains gains,
> static void lpphy_papd_cal_txpwr(struct b43_wldev *dev)
> {
> struct b43_phy_lp *lpphy = dev->phy.lp;
> - struct lpphy_tx_gains gains, oldgains;
> + struct lpphy_tx_gains oldgains;
> int old_txpctl, old_afe_ovr, old_rf, old_bbmult;
>
> lpphy_read_tx_pctl_mode_from_hardware(dev);
> @@ -1849,9 +1849,9 @@ static void lpphy_papd_cal_txpwr(struct b43_wldev *dev)
> lpphy_set_tx_power_control(dev, B43_LPPHY_TXPCTL_OFF);
>
> if (dev->dev->chip_id == 0x4325 && dev->dev->chip_rev == 0)
> - lpphy_papd_cal(dev, gains, 0, 1, 30);
> + lpphy_papd_cal(dev, oldgains, 0, 1, 30);
> else
> - lpphy_papd_cal(dev, gains, 0, 1, 65);
> + lpphy_papd_cal(dev, oldgains, 0, 1, 65);
>
> if (old_afe_ovr)
> lpphy_set_tx_gains(dev, oldgains);
>
Acked-by: Larry Finger <Larry.Finger@lwfinger.net>
Thanks. I will submit a patch that removes lpphy_papd_cal(). You are correct
that it is unlikely ever to be implemented.
Larry
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] b43: shut up clang -Wuninitialized variable warning
2019-03-22 14:37 [PATCH] b43: shut up clang -Wuninitialized variable warning Arnd Bergmann
2019-03-22 15:47 ` Larry Finger
@ 2019-03-22 16:06 ` Nathan Chancellor
2019-04-04 10:14 ` Kalle Valo
2 siblings, 0 replies; 4+ messages in thread
From: Nathan Chancellor @ 2019-03-22 16:06 UTC (permalink / raw)
To: Arnd Bergmann
Cc: Kalle Valo, David S. Miller, Larry Finger, Priit Laes,
clang-built-linux, Nick Desaulniers, linux-wireless, b43-dev,
netdev, linux-kernel
On Fri, Mar 22, 2019 at 03:37:02PM +0100, Arnd Bergmann wrote:
> Clang warns about what is clearly a case of passing an uninitalized
> variable into a static function:
>
> drivers/net/wireless/broadcom/b43/phy_lp.c:1852:23: error: variable 'gains' is uninitialized when used here
> [-Werror,-Wuninitialized]
> lpphy_papd_cal(dev, gains, 0, 1, 30);
> ^~~~~
> drivers/net/wireless/broadcom/b43/phy_lp.c:1838:2: note: variable 'gains' is declared here
> struct lpphy_tx_gains gains, oldgains;
> ^
> 1 error generated.
>
> However, this function is empty, and its arguments are never evaluated,
> so gcc in contrast does not warn here. Both compilers behave in a
> reasonable way as far as I can tell, so we should change the code
> to avoid the warning everywhere.
>
> We could just eliminate the lpphy_papd_cal() function entirely,
> given that it has had the TODO comment in it for 10 years now
> and is rather unlikely to ever get done. I'm doing a simpler
> change here, and just pass the 'oldgains' variable in that has
> been initialized, based on the guess that this is what was
> originally meant.
>
> Fixes: 2c0d6100da3e ("b43: LP-PHY: Begin implementing calibration & software RFKILL support")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
> ---
> drivers/net/wireless/broadcom/b43/phy_lp.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/net/wireless/broadcom/b43/phy_lp.c b/drivers/net/wireless/broadcom/b43/phy_lp.c
> index 46408a560814..aedee026c5e2 100644
> --- a/drivers/net/wireless/broadcom/b43/phy_lp.c
> +++ b/drivers/net/wireless/broadcom/b43/phy_lp.c
> @@ -1835,7 +1835,7 @@ static void lpphy_papd_cal(struct b43_wldev *dev, struct lpphy_tx_gains gains,
> static void lpphy_papd_cal_txpwr(struct b43_wldev *dev)
> {
> struct b43_phy_lp *lpphy = dev->phy.lp;
> - struct lpphy_tx_gains gains, oldgains;
> + struct lpphy_tx_gains oldgains;
> int old_txpctl, old_afe_ovr, old_rf, old_bbmult;
>
> lpphy_read_tx_pctl_mode_from_hardware(dev);
> @@ -1849,9 +1849,9 @@ static void lpphy_papd_cal_txpwr(struct b43_wldev *dev)
> lpphy_set_tx_power_control(dev, B43_LPPHY_TXPCTL_OFF);
>
> if (dev->dev->chip_id == 0x4325 && dev->dev->chip_rev == 0)
> - lpphy_papd_cal(dev, gains, 0, 1, 30);
> + lpphy_papd_cal(dev, oldgains, 0, 1, 30);
> else
> - lpphy_papd_cal(dev, gains, 0, 1, 65);
> + lpphy_papd_cal(dev, oldgains, 0, 1, 65);
>
> if (old_afe_ovr)
> lpphy_set_tx_gains(dev, oldgains);
> --
> 2.20.0
>
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] b43: shut up clang -Wuninitialized variable warning
2019-03-22 14:37 [PATCH] b43: shut up clang -Wuninitialized variable warning Arnd Bergmann
2019-03-22 15:47 ` Larry Finger
2019-03-22 16:06 ` Nathan Chancellor
@ 2019-04-04 10:14 ` Kalle Valo
2 siblings, 0 replies; 4+ messages in thread
From: Kalle Valo @ 2019-04-04 10:14 UTC (permalink / raw)
To: Arnd Bergmann
Cc: David S. Miller, Larry Finger, Arnd Bergmann, Priit Laes,
clang-built-linux, Nick Desaulniers, Nathan Chancellor,
linux-wireless, b43-dev, netdev, linux-kernel
Arnd Bergmann <arnd@arndb.de> wrote:
> Clang warns about what is clearly a case of passing an uninitalized
> variable into a static function:
>
> drivers/net/wireless/broadcom/b43/phy_lp.c:1852:23: error: variable 'gains' is uninitialized when used here
> [-Werror,-Wuninitialized]
> lpphy_papd_cal(dev, gains, 0, 1, 30);
> ^~~~~
> drivers/net/wireless/broadcom/b43/phy_lp.c:1838:2: note: variable 'gains' is declared here
> struct lpphy_tx_gains gains, oldgains;
> ^
> 1 error generated.
>
> However, this function is empty, and its arguments are never evaluated,
> so gcc in contrast does not warn here. Both compilers behave in a
> reasonable way as far as I can tell, so we should change the code
> to avoid the warning everywhere.
>
> We could just eliminate the lpphy_papd_cal() function entirely,
> given that it has had the TODO comment in it for 10 years now
> and is rather unlikely to ever get done. I'm doing a simpler
> change here, and just pass the 'oldgains' variable in that has
> been initialized, based on the guess that this is what was
> originally meant.
>
> Fixes: 2c0d6100da3e ("b43: LP-PHY: Begin implementing calibration & software RFKILL support")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> Acked-by: Larry Finger <Larry.Finger@lwfinger.net>
> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Patch applied to wireless-drivers-next.git, thanks.
d825db346270 b43: shut up clang -Wuninitialized variable warning
--
https://patchwork.kernel.org/patch/10865933/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
^ permalink raw reply [flat|nested] 4+ messages in thread