Re: [PATCH] misc: rtsx: Set setting_reg2 before use.

[Tom Rix]

On 5/16/22 8:56 AM, Nathan Chancellor wrote:
> On Mon, May 16, 2022 at 09:00:47AM -0400, Tom Rix wrote:
> > The clang build fails with
> > rts5261.c:406:13: error: variable 'setting_reg2' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
> >          } else if (efuse_valid == 0) {
> >                     ^~~~~~~~~~~~~~~~
> >
> > setting_reg2 is set in this block
> >    if (efuse_valid == 2 || efuse_valid == 3) {
> > ..
> >    } else if (efuse_valid == 0) {
> >      // default
> > ..
> >    }
> > But efuse_valid can also have a value of 1.
> > Change the 'else if' to 'else' to make the second block the default.
> >
> > Fixes: b1c5f3085149 ("misc: rtsx: add rts5261 efuse function")
> > Signed-off-by: Tom Rix <trix@xxxxxxxxxx>
> I am not sure if this fix is correct from a functional standpoint (i.e.
> is treating efuse_valid == 1 the same as efuse_valid == 0 correct?) but
> it is better than not handling this value altogether. For what it's
> worth:

I looked at how the code used to work, this seemed better than 
initializing to NULL.

> Reviewed-by: Nathan Chancellor <nathan@xxxxxxxxxx>
>
> As a side note, it is unfortunate that this change made it into -next
> when there was an outstanding report about this warning:

From the clang side, this is a build break and my static analysis infra 
goes down.

These build breaks seem to happening every week, is there a precommit 
clang gating test that could be done for -next ?

Tom

> https://lore.kernel.org/202205100220.WyAyhKap-lkp@xxxxxxxxx/
>
> > ---
> >   drivers/misc/cardreader/rts5261.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/misc/cardreader/rts5261.c b/drivers/misc/cardreader/rts5261.c
> > index 749cc5a46d13..f22634b14dc8 100644
> > --- a/drivers/misc/cardreader/rts5261.c
> > +++ b/drivers/misc/cardreader/rts5261.c
> > @@ -403,7 +403,7 @@ static void rts5261_init_from_hw(struct rtsx_pcr *pcr)
> >   			setting_reg1 = PCR_SETTING_REG4;
> >   			setting_reg2 = PCR_SETTING_REG5;
> >   		}
> > -	} else if (efuse_valid == 0) {
> > +	} else {
> >   		// default
> >   		setting_reg1 = PCR_SETTING_REG1;
> >   		setting_reg2 = PCR_SETTING_REG2;
> > --
> > 2.27.0
> Cheers,
> Nathan