Re: [PATCH 4/8]drivers:tmp.c Fix warning: variable 'rc' set but notused

[Justin P. Mattock]

On 06/15/2010 11:53 AM, Sergey V. wrote:
> On Tuesday 15 of June 2010 00:26:44 Justin P. Mattock wrote:
> > Im getting this warning when compiling:
> >   CC      drivers/char/tpm/tpm.o
> > drivers/char/tpm/tpm.c: In function 'tpm_gen_interrupt':
> > drivers/char/tpm/tpm.c:508:10: warning: variable 'rc' set but not used
> >
> > The below patch gets rid of the warning,
> > but I'm not sure if it's the best solution.
> >
> >   Signed-off-by: Justin P. Mattock<justinmattock@xxxxxxxxx>
> >
> > ---
> >   drivers/char/tpm/tpm.c |    2 ++
> >   1 files changed, 2 insertions(+), 0 deletions(-)
> >
> > diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c
> > index 05ad4a1..3d685dc 100644
> > --- a/drivers/char/tpm/tpm.c
> > +++ b/drivers/char/tpm/tpm.c
> > @@ -514,6 +514,8 @@ void tpm_gen_interrupt(struct tpm_chip *chip)
> >
> >   	rc = transmit_cmd(chip,&tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
> >   			"attempting to determine the timeouts");
> > +	if (!rc)
> > +		rc = 0;
> >   }
> >   EXPORT_SYMBOL_GPL(tpm_gen_interrupt);
> >
> > --
> > 1.7.1.rc1.21.gf3bd6
>
> Hi Justin
>
> IMHO
> See code of functions tpm_transmit(), transmit_cmd and tpm_gen_interrupt().
> In tpm_gen_interrupt() not need check rc for wrong value bacause if in function
> transmit_cmd() len == TPM_ERROR_SIZE then put a debug message (dev_dbg()).
> Again, if something wrong in tpm_transmit() then runs dev_err() and rc in
> tpm_gen_interrupt() get -E* value.
> So, we can remove unused rc variable in tpm_gen_interrupt().
>
> See patch below. Note: I not tested it.
>
>
> Subject: [PATCH] drivers: tpm.c: Remove unused variable 'rc'
>
> ---
>   drivers/char/tpm/tpm.c |    5 ++---
>   1 files changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c
> index 05ad4a1..f9f5b47 100644
> --- a/drivers/char/tpm/tpm.c
> +++ b/drivers/char/tpm/tpm.c
> @@ -505,15 +505,14 @@ ssize_t tpm_getcap(struct device *dev, __be32 subcap_id,
> cap_t *cap,
>   void tpm_gen_interrupt(struct tpm_chip *chip)
>   {
>   	struct	tpm_cmd_t tpm_cmd;
> -	ssize_t rc;
>
>   	tpm_cmd.header.in = tpm_getcap_header;
>   	tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
>   	tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
>   	tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
>
> -	rc = transmit_cmd(chip,&tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
> -			"attempting to determine the timeouts");
> +	transmit_cmd(chip,&tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
> +		     "attempting to determine the timeouts");
>   }
>   EXPORT_SYMBOL_GPL(tpm_gen_interrupt);



o.k. applied this patch and rebuilt, here is what I see:

  CC [M]  drivers/char/ipmi/ipmi_poweroff.o
  CC      drivers/char/tpm/tpm.o
  CC      drivers/char/tpm/tpm_bios.o
  CC      drivers/char/tpm/tpm_tis.o
  LD      drivers/char/tpm/built-in.o


looks good over here Thanks for sending this..

Justin P. Mattock
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