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From:   Alexander Lobakin <alexandr.lobakin@intel.com>
To:     Nathan Chancellor <nathan@kernel.org>
Cc:     Alexander Lobakin <alexandr.lobakin@intel.com>,
        Arnd Bergmann <arnd@arndb.de>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        linux-kernel@vger.kernel.org, llvm@lists.linux.dev,
        patches@lists.linux.dev, Dan Carpenter <dan.carpenter@oracle.com>,
        kernel test robot <lkp@intel.com>, Tom Rix <trix@redhat.com>,
        Ricky WU <ricky_wu@realtek.com>
Subject: Re: [PATCH] misc: rtsx: Fix clang -Wsometimes-uninitialized in rts5261_init_from_hw()
Date:   Mon,  6 Jun 2022 12:58:19 +0200
Message-Id: <20220606105819.349320-1-alexandr.lobakin@intel.com>
In-Reply-To: <20220523150521.2947108-1-nathan@kernel.org>
References: <20220523150521.2947108-1-nathan@kernel.org>
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From: Nathan Chancellor <nathan@kernel.org>
Date: Mon, 23 May 2022 08:05:22 -0700

> Clang warns:
> 
>   drivers/misc/cardreader/rts5261.c:406:13: error: variable 'setting_reg2' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
>           } else if (efuse_valid == 0) {
>                      ^~~~~~~~~~~~~~~~
>   drivers/misc/cardreader/rts5261.c:412:30: note: uninitialized use occurs here
>           pci_read_config_dword(pdev, setting_reg2, &lval2);
>                                       ^~~~~~~~~~~~
> 
> efuse_valid == 1 is not a valid value so just return early from the
> function to avoid using setting_reg2 uninitialized.
> 
> Fixes: b1c5f3085149 ("misc: rtsx: add rts5261 efuse function")
> Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
> Reported-by: kernel test robot <lkp@intel.com>
> Reported-by: Tom Rix <trix@redhat.com>
> Suggested-by: Ricky WU <ricky_wu@realtek.com>
> Signed-off-by: Nathan Chancellor <nathan@kernel.org>

Ping? Mainline 5.19-rc1 is now broken due to this.

> ---
> 
> This is basically a v2 of https://lore.kernel.org/20220516130047.3887590-1-trix@redhat.com/.
> 
>  drivers/misc/cardreader/rts5261.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/misc/cardreader/rts5261.c b/drivers/misc/cardreader/rts5261.c
> index 749cc5a46d13..b1e76030cafd 100644
> --- a/drivers/misc/cardreader/rts5261.c
> +++ b/drivers/misc/cardreader/rts5261.c
> @@ -407,6 +407,8 @@ static void rts5261_init_from_hw(struct rtsx_pcr *pcr)
>  		// default
>  		setting_reg1 = PCR_SETTING_REG1;
>  		setting_reg2 = PCR_SETTING_REG2;
> +	} else {
> +		return;
>  	}
>  
>  	pci_read_config_dword(pdev, setting_reg2, &lval2);
> 
> base-commit: 90de6805267f8c79cd2b1a36805071e257c39b5c
> -- 
> 2.36.1

Thanks,
Al