[PATCH] staging: rts5208: remove always true comparison

[PATCH] staging: rts5208: remove always true comparison

[Sudip Mukherjee]

the if comparison is always true as anything bitwise and-ing with 0x1E
can never be equal to 0x03.

Fixes bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=69881

Reported-by: David Binderman <dcb314@hotmail.com>
Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
---
 drivers/staging/rts5208/sd.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/staging/rts5208/sd.c b/drivers/staging/rts5208/sd.c
index a8d657b..2e3f1f4 100644
--- a/drivers/staging/rts5208/sd.c
+++ b/drivers/staging/rts5208/sd.c
@@ -4170,10 +4170,8 @@ RTY_SEND_CMD:
 				}
 
 			} else if (rsp_type == SD_RSP_TYPE_R0) {
-				if ((ptr[3] & 0x1E) != 0x03) {
-					rtsx_trace(chip);
-					return STATUS_FAIL;
-				}
+				rtsx_trace(chip);
+				return STATUS_FAIL;
 			}
 		}
 	}
-- 
1.8.1.2

Re: [PATCH] staging: rts5208: remove always true comparison

[Dan Carpenter]

On Thu, May 14, 2015 at 07:55:59PM +0530, Sudip Mukherjee wrote:
> the if comparison is always true as anything bitwise and-ing with 0x1E
> can never be equal to 0x03.
> 
> Fixes bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=69881
> 

It doesn't fix anything though, it just silences the warning.  Warnings
are nice because they let you know that the code is buggy.  It's better
to leave them there instead of making the bugs more complicated to find.

Micky Ching might know if this is the right thing to do or if something
else was intended instead of 0x03?

regards,
dan carpenter

> Reported-by: David Binderman <dcb314@hotmail.com>
> Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
> ---
>  drivers/staging/rts5208/sd.c | 6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/staging/rts5208/sd.c b/drivers/staging/rts5208/sd.c
> index a8d657b..2e3f1f4 100644
> --- a/drivers/staging/rts5208/sd.c
> +++ b/drivers/staging/rts5208/sd.c
> @@ -4170,10 +4170,8 @@ RTY_SEND_CMD:
>  				}
>  
>  			} else if (rsp_type == SD_RSP_TYPE_R0) {
> -				if ((ptr[3] & 0x1E) != 0x03) {
> -					rtsx_trace(chip);
> -					return STATUS_FAIL;
> -				}
> +				rtsx_trace(chip);
> +				return STATUS_FAIL;
>  			}
>  		}
>  	}
> -- 
> 1.8.1.2
> 
> _______________________________________________
> devel mailing list
> devel@linuxdriverproject.org
> http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel

Re: [PATCH] staging: rts5208: remove always true comparison

[Sudip Mukherjee]

On Thu, May 14, 2015 at 06:18:59PM +0300, Dan Carpenter wrote:
> On Thu, May 14, 2015 at 07:55:59PM +0530, Sudip Mukherjee wrote:
> > the if comparison is always true as anything bitwise and-ing with 0x1E
> > can never be equal to 0x03.
> > 
> > Fixes bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=69881
> > 
> 
> It doesn't fix anything though, it just silences the warning.  Warnings
> are nice because they let you know that the code is buggy.  It's better
> to leave them there instead of making the bugs more complicated to find.

but I am not seeing any warnings. I tried with make W=1, tried with
sparse, but still no warning. am i missing something?

regards
sudip

Re: [PATCH] staging: rts5208: remove always true comparison

[Dan Carpenter]

On Fri, May 15, 2015 at 03:46:49PM +0530, Sudip Mukherjee wrote:
> On Thu, May 14, 2015 at 06:18:59PM +0300, Dan Carpenter wrote:
> > On Thu, May 14, 2015 at 07:55:59PM +0530, Sudip Mukherjee wrote:
> > > the if comparison is always true as anything bitwise and-ing with 0x1E
> > > can never be equal to 0x03.
> > > 
> > > Fixes bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=69881
> > > 
> > 
> > It doesn't fix anything though, it just silences the warning.  Warnings
> > are nice because they let you know that the code is buggy.  It's better
> > to leave them there instead of making the bugs more complicated to find.
> 
> but I am not seeing any warnings. I tried with make W=1, tried with
> sparse, but still no warning. am i missing something?

David Binderman is using a static checker of some kind.  I'm not sure
which.  It might be cppcheck or it might be something private.

regards,
dan carpenter

Re: [PATCH] staging: rts5208: remove always true comparison

[Sudip Mukherjee]

On Mon, May 25, 2015 at 07:22:40PM +0300, Dan Carpenter wrote:
> On Fri, May 15, 2015 at 03:46:49PM +0530, Sudip Mukherjee wrote:
> > On Thu, May 14, 2015 at 06:18:59PM +0300, Dan Carpenter wrote:
> > > On Thu, May 14, 2015 at 07:55:59PM +0530, Sudip Mukherjee wrote:
> > > > the if comparison is always true as anything bitwise and-ing with 0x1E
> > > > can never be equal to 0x03.
> > > > 
> > > > Fixes bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=69881
> > > > 
> > > 
> > > It doesn't fix anything though, it just silences the warning.  Warnings
> > > are nice because they let you know that the code is buggy.  It's better
> > > to leave them there instead of making the bugs more complicated to find.
> > 
> > but I am not seeing any warnings. I tried with make W=1, tried with
> > sparse, but still no warning. am i missing something?
> 
> David Binderman is using a static checker of some kind.  I'm not sure
> which.  It might be cppcheck or it might be something private.
Its not cppcheck. I use it when I feel lazy. :) And if it is something
private then only David can see the warning, in that case why do we need
to keep a code which is obviously wrong?

regards
sudip