Re: [PATCH v1 3/5] char: tpm: rewrite "tpm_tis_req_canceled()"

[Jerry Snitselaar]

On Sun Nov 10 19, amirmizi6@xxxxxxxxx wrote:
> From: Amir Mizinski <amirmizi6@xxxxxxxxx>
>
> using this function while read/write data resulted in aborted operation.
> after investigating according to TCG TPM Profile (PTP) Specifications,
> i found cancel should happen only if TPM_STS.commandReady bit is lit
> and couldn't find a case when the current condition is valid.
> also only cmdReady bit need to be compared instead of the full lower status register byte.
>
> Signed-off-by: Amir Mizinski <amirmizi6@xxxxxxxxx>
> ---
> drivers/char/tpm/tpm_tis_core.c | 12 +-----------
> 1 file changed, 1 insertion(+), 11 deletions(-)
>
> diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
> index ce7f8a1..9016f06 100644
> --- a/drivers/char/tpm/tpm_tis_core.c
> +++ b/drivers/char/tpm/tpm_tis_core.c
> @@ -627,17 +627,7 @@ static int probe_itpm(struct tpm_chip *chip)
>
> static bool tpm_tis_req_canceled(struct tpm_chip *chip, u8 status)
> {
> -	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
> -
> -	switch (priv->manufacturer_id) {
> -	case TPM_VID_WINBOND:
> -		return ((status == TPM_STS_VALID) ||
> -			(status == (TPM_STS_VALID | TPM_STS_COMMAND_READY)));
> -	case TPM_VID_STM:
> -		return (status == (TPM_STS_VALID | TPM_STS_COMMAND_READY));

Stefan were these cases you found that were deviating from the spec? Wondering
if dropping these will cause issues for these devices.

> -	default:
> -		return (status == TPM_STS_COMMAND_READY);
> -	}
> +	return ((status & TPM_STS_COMMAND_READY) == TPM_STS_COMMAND_READY);
> }
>
> static irqreturn_t tis_int_handler(int dummy, void *dev_id)
> --
> 2.7.4