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From: Valdis.Kletnieks on 14 Jun 2010 20:20
On Mon, 14 Jun 2010 13:26:44 PDT, "Justin P. Mattock" said:
> 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.

> rc = transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
> "attempting to determine the timeouts");
> + if (!rc)
> + rc = 0;
> }

Good thing that's a void function. ;)

Unless transmit_cmd() is marked 'must_check', maybe losing the 'rc =' would
be a better solution?
From: Valdis.Kletnieks on 15 Jun 2010 00:00
On Mon, 14 Jun 2010 19:12:31 PDT, "Justin P. Mattock" said:

> what I tried was this:
>
> if (!rc)
> printk("test........"\n")
>
> and everything looked good,
> but as a soon as I changed
>
> rc = transmit_cmd(chip,&tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
> "attempting to determine the timeouts");
>
> to this:
>
> rc = transmit_cmd(chip,&tpm_cmd, TPM_INTERNAL_RESULT_SIZE);
>
> if (!rc)
> printk("attempting to determine the timeouts\n");

*baffled* Why did you think that would work? transmit_cmd()s signature
has 4 parameters.
From: Sergey V. on 15 Jun 2010 15:00
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(a)gmail.com>
>
> ---
> 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);

--
1.7.1
--
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