Re: [PATCH] mmc: sdhci-cadence: Fix -Wuninitialized in sdhci_cdns_tune_blkgap()

[Dan Carpenter <dan.carpenter@linaro.org>]

On Wed, Aug 20, 2025 at 10:07:35AM +0200, Benoît Monin wrote:
> > --- a/drivers/mmc/host/sdhci-cadence.c
> > +++ b/drivers/mmc/host/sdhci-cadence.c
> > @@ -288,13 +288,12 @@ static int sdhci_cdns_tune_blkgap(struct mmc_host *mmc)
> >  	void __iomem *hrs38_reg = priv->hrs_addr + SDHCI_CDNS_HRS38;
> >  	int ret;
> >  	u32 gap;
> > -	u32 hrs37_mode;
> >  
> >  	/* Currently only needed in HS200 mode */
> >  	if (host->timing != MMC_TIMING_MMC_HS200)
> >  		return 0;
> >  
> > -	writel(hrs37_mode, hrs37_reg);
> > +	writel(SDHCI_CDNS_HRS37_MODE_MMC_HS200, hrs37_reg);
> >  
> >  	for (gap = 0; gap <= SDHCI_CDNS_HRS38_BLKGAP_MAX; gap++) {
> >  		writel(gap, hrs38_reg);
> > 
> Thanks for the catch!
> 
> I don't get how gcc does not raise a warning here, only clang does. I
> did build with gcc-11 and gcc-15 and they don't complain about this
> uninitialized variable.
> 

We disabled uninitialized variable checking on GCC.  It was too crazy
and especially if we want to use -Werror.

Smatch also detects this bug.

regards,
dan carpenter