linux-kernel - Re: [PATCH] tpm_tis: use default timeout value if chip reports it as zero

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Message-ID: <20170116094202.bng7zfznepw7s5la@intel.com>
Date:   Mon, 16 Jan 2017 11:42:02 +0200
From:   Jarkko Sakkinen <jarkko.sakkinen@...ux.intel.com>
To:     "Maciej S. Szmigiero" <mail@...iej.szmigiero.name>
Cc:     tpmdd-devel@...ts.sourceforge.net,
        linux-kernel <linux-kernel@...r.kernel.org>,
        Peter Huewe <peterhuewe@....de>,
        Marcel Selhorst <tpmdd@...horst.net>,
        Christophe Ricard <christophe.ricard@...il.com>,
        Jason Gunthorpe <jgunthorpe@...idianresearch.com>
Subject: Re: [PATCH] tpm_tis: use default timeout value if chip reports it as
 zero

On Fri, Jan 13, 2017 at 10:37:00PM +0100, Maciej S. Szmigiero wrote:
> Since commit 1107d065fdf1 ("tpm_tis: Introduce intermediate layer for TPM
> access") Atmel 3203 TPM on ThinkPad X61S (TPM firmware version 13.9) no
> longer works.
> The initialization proceeds fine until we get and start using chip-reported
> timeouts - and the chip reports C and D timeouts of zero.
> 
> It turns out that until commit 8e54caf407b98e ("tpm: Provide a generic
> means to override the chip returned timeouts") we had actually let default
> timeout values remain in this case, so let's bring back this behavior to
> make chips like Atmel 3203 work again.
> 
> Use a common code that was introduced by that commit so a warning is
> printed in this case and /sys/class/tpm/tpm*/timeouts correctly says the
> timeouts aren't chip-original.
> 
> Signed-off-by: Maciej S. Szmigiero <mail@...iej.szmigiero.name>
> 
> Fixes: 1107d065fdf1 ("tpm_tis: Introduce intermediate layer for TPM access")
> Cc: stable@...r.kernel.org

Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@...ux.intel.com>

/Jarkko

> ---
> This replaces "tpm_tis: override reported C and D timeouts for Atmel 3203"
> submission.
> 
>  drivers/char/tpm/tpm-interface.c | 53 ++++++++++++++++++++++++----------------
>  1 file changed, 32 insertions(+), 21 deletions(-)
> 
> diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
> index fecdd3fa8126..a3461cbdde5f 100644
> --- a/drivers/char/tpm/tpm-interface.c
> +++ b/drivers/char/tpm/tpm-interface.c
> @@ -522,8 +522,7 @@ static int tpm_startup(struct tpm_chip *chip, __be16 startup_type)
>  int tpm_get_timeouts(struct tpm_chip *chip)
>  {
>  	cap_t cap;
> -	unsigned long new_timeout[4];
> -	unsigned long old_timeout[4];
> +	unsigned long timeout_old[4], timeout_chip[4], timeout_eff[4];
>  	ssize_t rc;
>  
>  	if (chip->flags & TPM_CHIP_FLAG_HAVE_TIMEOUTS)
> @@ -564,11 +563,15 @@ int tpm_get_timeouts(struct tpm_chip *chip)
>  		return rc;
>  	}
>  
> -	old_timeout[0] = be32_to_cpu(cap.timeout.a);
> -	old_timeout[1] = be32_to_cpu(cap.timeout.b);
> -	old_timeout[2] = be32_to_cpu(cap.timeout.c);
> -	old_timeout[3] = be32_to_cpu(cap.timeout.d);
> -	memcpy(new_timeout, old_timeout, sizeof(new_timeout));
> +	timeout_old[0] = jiffies_to_usecs(chip->timeout_a);
> +	timeout_old[1] = jiffies_to_usecs(chip->timeout_b);
> +	timeout_old[2] = jiffies_to_usecs(chip->timeout_c);
> +	timeout_old[3] = jiffies_to_usecs(chip->timeout_d);
> +	timeout_chip[0] = be32_to_cpu(cap.timeout.a);
> +	timeout_chip[1] = be32_to_cpu(cap.timeout.b);
> +	timeout_chip[2] = be32_to_cpu(cap.timeout.c);
> +	timeout_chip[3] = be32_to_cpu(cap.timeout.d);
> +	memcpy(timeout_eff, timeout_chip, sizeof(timeout_eff));
>  
>  	/*
>  	 * Provide ability for vendor overrides of timeout values in case
> @@ -576,16 +579,24 @@ int tpm_get_timeouts(struct tpm_chip *chip)
>  	 */
>  	if (chip->ops->update_timeouts != NULL)
>  		chip->timeout_adjusted =
> -			chip->ops->update_timeouts(chip, new_timeout);
> +			chip->ops->update_timeouts(chip, timeout_eff);
>  
>  	if (!chip->timeout_adjusted) {
> -		/* Don't overwrite default if value is 0 */
> -		if (new_timeout[0] != 0 && new_timeout[0] < 1000) {
> -			int i;
> +		/* Restore default if chip reported 0 */
> +		int i;
>  
> +		for (i = 0; i < ARRAY_SIZE(timeout_eff); i++) {
> +			if (timeout_eff[i])
> +				continue;
> +
> +			timeout_eff[i] = timeout_old[i];
> +			chip->timeout_adjusted = true;
> +		}
> +
> +		if (timeout_eff[0] != 0 && timeout_eff[0] < 1000) {
>  			/* timeouts in msec rather usec */
> -			for (i = 0; i != ARRAY_SIZE(new_timeout); i++)
> -				new_timeout[i] *= 1000;
> +			for (i = 0; i != ARRAY_SIZE(timeout_eff); i++)
> +				timeout_eff[i] *= 1000;
>  			chip->timeout_adjusted = true;
>  		}
>  	}
> @@ -594,16 +605,16 @@ int tpm_get_timeouts(struct tpm_chip *chip)
>  	if (chip->timeout_adjusted) {
>  		dev_info(&chip->dev,
>  			 HW_ERR "Adjusting reported timeouts: A %lu->%luus B %lu->%luus C %lu->%luus D %lu->%luus\n",
> -			 old_timeout[0], new_timeout[0],
> -			 old_timeout[1], new_timeout[1],
> -			 old_timeout[2], new_timeout[2],
> -			 old_timeout[3], new_timeout[3]);
> +			 timeout_chip[0], timeout_eff[0],
> +			 timeout_chip[1], timeout_eff[1],
> +			 timeout_chip[2], timeout_eff[2],
> +			 timeout_chip[3], timeout_eff[3]);
>  	}
>  
> -	chip->timeout_a = usecs_to_jiffies(new_timeout[0]);
> -	chip->timeout_b = usecs_to_jiffies(new_timeout[1]);
> -	chip->timeout_c = usecs_to_jiffies(new_timeout[2]);
> -	chip->timeout_d = usecs_to_jiffies(new_timeout[3]);
> +	chip->timeout_a = usecs_to_jiffies(timeout_eff[0]);
> +	chip->timeout_b = usecs_to_jiffies(timeout_eff[1]);
> +	chip->timeout_c = usecs_to_jiffies(timeout_eff[2]);
> +	chip->timeout_d = usecs_to_jiffies(timeout_eff[3]);
>  
>  	rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_DURATION, &cap,
>  			"attempting to determine the durations");
>