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>
---

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

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

On Mon, Jun 06, 2022 at 12:58:19PM +0200, Alexander Lobakin wrote:
> 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.

Perhaps use a different compiler?  :)

It's in my "to apply" queue, will get there hopefully this week, it came
in during the merge window which prevented me from touching it.  You
know this...

thanks,

greg k-h

On Mon, May 23, 2022 at 5:05 PM Nathan Chancellor <nathan@kernel.org> wrote:
>
> 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>

Looks good to me,

Acked-by: Arnd Bergmann <arnd@arndb.de>