[PATCH] tpm_i2c_nuvoton: Use common error handling code in i2c_nuvoton_send()

[PATCH] tpm_i2c_nuvoton: Use common error handling code in i2c_nuvoton_send()

[SF Markus Elfring]

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Sat, 21 Oct 2017 22:07:39 +0200

Add a jump target so that a bit of exception handling can be better reused
at the end of this function.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
 drivers/char/tpm/tpm_i2c_nuvoton.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/char/tpm/tpm_i2c_nuvoton.c b/drivers/char/tpm/tpm_i2c_nuvoton.c
index c6428771841f..f0037e9e2d0e 100644
--- a/drivers/char/tpm/tpm_i2c_nuvoton.c
+++ b/drivers/char/tpm/tpm_i2c_nuvoton.c
@@ -440,15 +440,13 @@ static int i2c_nuvoton_send(struct tpm_chip *chip, u8 *buf, size_t len)
 	}
 	if (rc < 0) {
 		/* retries == TPM_RETRY */
-		i2c_nuvoton_ready(chip);
-		return rc;
+		goto write_ready;
 	}
 	/* execute the TPM command */
 	rc = i2c_nuvoton_write_status(client, TPM_STS_GO);
 	if (rc < 0) {
 		dev_err(dev, "%s() fail to write Go\n", __func__);
-		i2c_nuvoton_ready(chip);
-		return rc;
+		goto write_ready;
 	}
 	ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
 	rc = i2c_nuvoton_wait_for_data_avail(chip,
@@ -457,12 +455,15 @@ static int i2c_nuvoton_send(struct tpm_chip *chip, u8 *buf, size_t len)
 					     &priv->read_queue);
 	if (rc) {
 		dev_err(dev, "%s() timeout command duration\n", __func__);
-		i2c_nuvoton_ready(chip);
-		return rc;
+		goto write_ready;
 	}
 
 	dev_dbg(dev, "%s() -> %zd\n", __func__, len);
 	return len;
+
+write_ready:
+	i2c_nuvoton_ready(chip);
+	return rc;
 }
 
 static bool i2c_nuvoton_req_canceled(struct tpm_chip *chip, u8 status)
-- 
2.14.2

Re: [PATCH] tpm_i2c_nuvoton: Use common error handling code in i2c_nuvoton_send()

[Jarkko Sakkinen]

On Sat, Oct 21, 2017 at 10:11:36PM +0200, SF Markus Elfring wrote:
> From: Markus Elfring <elfring@users.sourceforge.net>
> Date: Sat, 21 Oct 2017 22:07:39 +0200
> 
> Add a jump target so that a bit of exception handling can be better reused
> at the end of this function.
> 
> This issue was detected by using the Coccinelle software.
> 
> Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
> ---
>  drivers/char/tpm/tpm_i2c_nuvoton.c | 13 +++++++------
>  1 file changed, 7 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/char/tpm/tpm_i2c_nuvoton.c b/drivers/char/tpm/tpm_i2c_nuvoton.c
> index c6428771841f..f0037e9e2d0e 100644
> --- a/drivers/char/tpm/tpm_i2c_nuvoton.c
> +++ b/drivers/char/tpm/tpm_i2c_nuvoton.c
> @@ -440,15 +440,13 @@ static int i2c_nuvoton_send(struct tpm_chip *chip, u8 *buf, size_t len)
>  	}
>  	if (rc < 0) {
>  		/* retries == TPM_RETRY */
> -		i2c_nuvoton_ready(chip);
> -		return rc;
> +		goto write_ready;
>  	}
>  	/* execute the TPM command */
>  	rc = i2c_nuvoton_write_status(client, TPM_STS_GO);
>  	if (rc < 0) {
>  		dev_err(dev, "%s() fail to write Go\n", __func__);
> -		i2c_nuvoton_ready(chip);
> -		return rc;
> +		goto write_ready;
>  	}
>  	ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
>  	rc = i2c_nuvoton_wait_for_data_avail(chip,
> @@ -457,12 +455,15 @@ static int i2c_nuvoton_send(struct tpm_chip *chip, u8 *buf, size_t len)
>  					     &priv->read_queue);
>  	if (rc) {
>  		dev_err(dev, "%s() timeout command duration\n", __func__);
> -		i2c_nuvoton_ready(chip);
> -		return rc;
> +		goto write_ready;
>  	}
>  
>  	dev_dbg(dev, "%s() -> %zd\n", __func__, len);
>  	return len;
> +
> +write_ready:
> +	i2c_nuvoton_ready(chip);
> +	return rc;
>  }
>  
>  static bool i2c_nuvoton_req_canceled(struct tpm_chip *chip, u8 status)
> -- 
> 2.14.2
> 

Setting the commandReady bit gives means to abort the command. Setting
the bit is not the end goal. Use something like err_cancel instead.

/Jarkko

Re: [PATCH] tpm_i2c_nuvoton: Use common error handling code in i2c_nuvoton_send()

[SF Markus Elfring]

>> @@ -457,12 +455,15 @@ static int i2c_nuvoton_send(struct tpm_chip *chip, u8 *buf, size_t len)
>>  					     &priv->read_queue);
>>  	if (rc) {
>>  		dev_err(dev, "%s() timeout command duration\n", __func__);
>> -		i2c_nuvoton_ready(chip);
>> -		return rc;
>> +		goto write_ready;
>>  	}
>>  
>>  	dev_dbg(dev, "%s() -> %zd\n", __func__, len);
>>  	return len;
>> +
>> +write_ready:
>> +	i2c_nuvoton_ready(chip);
>> +	return rc;
>>  }
>>  
>>  static bool i2c_nuvoton_req_canceled(struct tpm_chip *chip, u8 status)
>> -- 
>> 2.14.2
>>
> 
> Setting the commandReady bit gives means to abort the command.
> Setting the bit is not the end goal.

Does your constructive feedback mean that there are any more implementation details
to consider besides the suggested code layout adjustment?


> Use something like err_cancel instead.

I am unsure about this suggestion. Will a simple replacement be sufficient
at the end?

Regards,
Markus