Re: [PATCH] mmc: sdhci-of-dwcmshc: Use logical OR instead of bitwise OR in dwcmshc_probe()

[Adrian Hunter <adrian.hunter@intel.com>]

On 17/11/23 03:46, Nathan Chancellor wrote:
> Clang warns (or errors with CONFIG_WERROR=y):
> 
>   drivers/mmc/host/sdhci-of-dwcmshc.c:873:7: error: use of bitwise '|' with boolean operands [-Werror,-Wbitwise-instead-of-logical]
>     873 |                 if ((device_property_read_bool(dev, "mmc-ddr-1_8v")) |
>         |                     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>     874 |                     (device_property_read_bool(dev, "mmc-hs200-1_8v")) |
>         |                     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>         |                                                                        ||
>     875 |                     (device_property_read_bool(dev, "mmc-hs400-1_8v")))
>         |                     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>   drivers/mmc/host/sdhci-of-dwcmshc.c:873:7: note: cast one or both operands to int to silence this warning
>   drivers/mmc/host/sdhci-of-dwcmshc.c:873:7: error: use of bitwise '|' with boolean operands [-Werror,-Wbitwise-instead-of-logical]
>     873 |                 if ((device_property_read_bool(dev, "mmc-ddr-1_8v")) |
>         |                     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>         |                                                                      ||
>     874 |                     (device_property_read_bool(dev, "mmc-hs200-1_8v")) |
>         |                     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>   drivers/mmc/host/sdhci-of-dwcmshc.c:873:7: note: cast one or both operands to int to silence this warning
>   2 errors generated.
> 
> There is little reason for this if statement to use bitwise ORs, as the
> short circuiting of logical OR does not need to be avoided in this
> context; it would be wasteful to call device_property_read_bool() three
> times if the first two calls returned true. Switch to logical OR to fix
> the warning.
> 
> While in the area, the parentheses around the calls to
> device_property_read_bool() are not necessary and make the if statement
> harder to read, so remove them.
> 
> Closes: https://github.com/ClangBuiltLinux/linux/issues/1960
> Fixes: aff35fbc7830 ("mmc: sdhci-of-dwcmshc: Add support for T-Head TH1520")
> Signed-off-by: Nathan Chancellor <nathan@kernel.org>

Acked-by: Adrian Hunter <adrian.hunter@intel.com>

> ---
>  drivers/mmc/host/sdhci-of-dwcmshc.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/mmc/host/sdhci-of-dwcmshc.c b/drivers/mmc/host/sdhci-of-dwcmshc.c
> index 0eb72544c09e..a1f57af6acfb 100644
> --- a/drivers/mmc/host/sdhci-of-dwcmshc.c
> +++ b/drivers/mmc/host/sdhci-of-dwcmshc.c
> @@ -870,9 +870,9 @@ static int dwcmshc_probe(struct platform_device *pdev)
>  	if (pltfm_data == &sdhci_dwcmshc_th1520_pdata) {
>  		priv->delay_line = PHY_SDCLKDL_DC_DEFAULT;
>  
> -		if ((device_property_read_bool(dev, "mmc-ddr-1_8v")) |
> -		    (device_property_read_bool(dev, "mmc-hs200-1_8v")) |
> -		    (device_property_read_bool(dev, "mmc-hs400-1_8v")))
> +		if (device_property_read_bool(dev, "mmc-ddr-1_8v") ||
> +		    device_property_read_bool(dev, "mmc-hs200-1_8v") ||
> +		    device_property_read_bool(dev, "mmc-hs400-1_8v"))
>  			priv->flags |= FLAG_IO_FIXED_1V8;
>  		else
>  			priv->flags &= ~FLAG_IO_FIXED_1V8;
> 
> ---
> base-commit: 3f00051234f02d0d9d1f63b9a334d0fd4c65b6ca
> change-id: 20231116-sdhci-of-dwcmshc-fix-wbitwise-instead-of-logical-bf8fed73b5bb
> 
> Best regards,