[tpmdd-devel,2/2] tpm: add sleep only for retry in i2c_nuvoton_write_status()

Submitted by Nayna Jain on March 10, 2017, 6:45 p.m.

Details

Message ID 1489171554-6844-2-git-send-email-nayna@linux.vnet.ibm.com
State New
Headers show

Commit Message

Nayna Jain March 10, 2017, 6:45 p.m.
Currently, there is an unnecessary 1 msec delay added in
i2c_nuvoton_write_status() for the successful case. This 
function is called multiple times during send() and recv(),
which implies adding multiple extra delays for every TPM
operation.

This patch calls usleep_range() only if retry is to be done.

Signed-off-by: Nayna Jain <nayna@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org (linux-4.8)
Reviewed-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
---
 drivers/char/tpm/tpm_i2c_nuvoton.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

Comments

Mimi Zohar March 13, 2017, 2:54 p.m.
Hi Jarkko,

On Fri, 2017-03-10 at 13:45 -0500, Nayna Jain wrote:
> Currently, there is an unnecessary 1 msec delay added in
> i2c_nuvoton_write_status() for the successful case. This 
> function is called multiple times during send() and recv(),
> which implies adding multiple extra delays for every TPM
> operation.
> 
> This patch calls usleep_range() only if retry is to be done.
> 
> Signed-off-by: Nayna Jain <nayna@linux.vnet.ibm.com>
> Cc: stable@vger.kernel.org (linux-4.8)
> Reviewed-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

Either Reviewed-by/Acked-by is fine. 

Can you pick up this patch and replace the original version of "tpm:
msleep() delays - replace with usleep_range()" with the one Nayna
posted?

Thanks!

Mimi

> ---
>  drivers/char/tpm/tpm_i2c_nuvoton.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/char/tpm/tpm_i2c_nuvoton.c b/drivers/char/tpm/tpm_i2c_nuvoton.c
> index 0c98c42..c642877 100644
> --- a/drivers/char/tpm/tpm_i2c_nuvoton.c
> +++ b/drivers/char/tpm/tpm_i2c_nuvoton.c
> @@ -124,8 +124,9 @@ static s32 i2c_nuvoton_write_status(struct i2c_client *client, u8 data)
>  	/* this causes the current command to be aborted */
>  	for (i = 0, status = -1; i < TPM_I2C_RETRY_COUNT && status < 0; i++) {
>  		status = i2c_nuvoton_write_buf(client, TPM_STS, 1, &data);
> -		usleep_range(TPM_I2C_BUS_DELAY, TPM_I2C_BUS_DELAY
> -			     + TPM_I2C_DELAY_RANGE);
> +		if (status < 0)
> +			usleep_range(TPM_I2C_BUS_DELAY, TPM_I2C_BUS_DELAY
> +				     + TPM_I2C_DELAY_RANGE);
>  	}
>  	return status;
>  }



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Jarkko Sakkinen March 13, 2017, 6:26 p.m.
On Mon, Mar 13, 2017 at 10:54:22AM -0400, Mimi Zohar wrote:
> Hi Jarkko,
> 
> On Fri, 2017-03-10 at 13:45 -0500, Nayna Jain wrote:
> > Currently, there is an unnecessary 1 msec delay added in
> > i2c_nuvoton_write_status() for the successful case. This 
> > function is called multiple times during send() and recv(),
> > which implies adding multiple extra delays for every TPM
> > operation.
> > 
> > This patch calls usleep_range() only if retry is to be done.
> > 
> > Signed-off-by: Nayna Jain <nayna@linux.vnet.ibm.com>
> > Cc: stable@vger.kernel.org (linux-4.8)
> > Reviewed-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
> 
> Either Reviewed-by/Acked-by is fine. 
> 
> Can you pick up this patch and replace the original version of "tpm:
> msleep() delays - replace with usleep_range()" with the one Nayna
> posted?
> 
> Thanks!
> 
> Mimi

Yes, sure. I'll try to get that done as soon as possible..

/Jarkko

> 
> > ---
> >  drivers/char/tpm/tpm_i2c_nuvoton.c | 5 +++--
> >  1 file changed, 3 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/char/tpm/tpm_i2c_nuvoton.c b/drivers/char/tpm/tpm_i2c_nuvoton.c
> > index 0c98c42..c642877 100644
> > --- a/drivers/char/tpm/tpm_i2c_nuvoton.c
> > +++ b/drivers/char/tpm/tpm_i2c_nuvoton.c
> > @@ -124,8 +124,9 @@ static s32 i2c_nuvoton_write_status(struct i2c_client *client, u8 data)
> >  	/* this causes the current command to be aborted */
> >  	for (i = 0, status = -1; i < TPM_I2C_RETRY_COUNT && status < 0; i++) {
> >  		status = i2c_nuvoton_write_buf(client, TPM_STS, 1, &data);
> > -		usleep_range(TPM_I2C_BUS_DELAY, TPM_I2C_BUS_DELAY
> > -			     + TPM_I2C_DELAY_RANGE);
> > +		if (status < 0)
> > +			usleep_range(TPM_I2C_BUS_DELAY, TPM_I2C_BUS_DELAY
> > +				     + TPM_I2C_DELAY_RANGE);
> >  	}
> >  	return status;
> >  }
> 
> 

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Jarkko Sakkinen March 17, 2017, 7:02 p.m.
On Fri, Mar 10, 2017 at 01:45:54PM -0500, Nayna Jain wrote:
> Currently, there is an unnecessary 1 msec delay added in
> i2c_nuvoton_write_status() for the successful case. This 
> function is called multiple times during send() and recv(),
> which implies adding multiple extra delays for every TPM
> operation.
> 
> This patch calls usleep_range() only if retry is to be done.
> 
> Signed-off-by: Nayna Jain <nayna@linux.vnet.ibm.com>
> Cc: stable@vger.kernel.org (linux-4.8)
> Reviewed-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

I applied this too.

/Jarkko

> ---
>  drivers/char/tpm/tpm_i2c_nuvoton.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/char/tpm/tpm_i2c_nuvoton.c b/drivers/char/tpm/tpm_i2c_nuvoton.c
> index 0c98c42..c642877 100644
> --- a/drivers/char/tpm/tpm_i2c_nuvoton.c
> +++ b/drivers/char/tpm/tpm_i2c_nuvoton.c
> @@ -124,8 +124,9 @@ static s32 i2c_nuvoton_write_status(struct i2c_client *client, u8 data)
>  	/* this causes the current command to be aborted */
>  	for (i = 0, status = -1; i < TPM_I2C_RETRY_COUNT && status < 0; i++) {
>  		status = i2c_nuvoton_write_buf(client, TPM_STS, 1, &data);
> -		usleep_range(TPM_I2C_BUS_DELAY, TPM_I2C_BUS_DELAY
> -			     + TPM_I2C_DELAY_RANGE);
> +		if (status < 0)
> +			usleep_range(TPM_I2C_BUS_DELAY, TPM_I2C_BUS_DELAY
> +				     + TPM_I2C_DELAY_RANGE);
>  	}
>  	return status;
>  }
> -- 
> 2.9.3
> 
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diff --git a/drivers/char/tpm/tpm_i2c_nuvoton.c b/drivers/char/tpm/tpm_i2c_nuvoton.c
index 0c98c42..c642877 100644
--- a/drivers/char/tpm/tpm_i2c_nuvoton.c
+++ b/drivers/char/tpm/tpm_i2c_nuvoton.c
@@ -124,8 +124,9 @@  static s32 i2c_nuvoton_write_status(struct i2c_client *client, u8 data)
 	/* this causes the current command to be aborted */
 	for (i = 0, status = -1; i < TPM_I2C_RETRY_COUNT && status < 0; i++) {
 		status = i2c_nuvoton_write_buf(client, TPM_STS, 1, &data);
-		usleep_range(TPM_I2C_BUS_DELAY, TPM_I2C_BUS_DELAY
-			     + TPM_I2C_DELAY_RANGE);
+		if (status < 0)
+			usleep_range(TPM_I2C_BUS_DELAY, TPM_I2C_BUS_DELAY
+				     + TPM_I2C_DELAY_RANGE);
 	}
 	return status;
 }