From: Amir Mizinski <[email protected]>
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 <[email protected]>
---
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 6c4f232..18b9dc4 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -710,17 +710,7 @@ 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));
- 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
===========================================================================================
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On Tue, Mar 31, 2020 at 02:32:03PM +0300, [email protected] wrote:
> From: Amir Mizinski <[email protected]>
>
> 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 <[email protected]>
We don't care about spec's. We care about hardware and not all hardware
follows specifications.
Please fix the exact thing you want to fix (and please provide a fixes
tag).
/Jarkko
On 3/31/2020 8:13 AM, Jarkko Sakkinen wrote:
> On Tue, Mar 31, 2020 at 02:32:03PM +0300, [email protected] wrote:
>> From: Amir Mizinski <[email protected]>
>>
>> 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 <[email protected]>
>
> We don't care about spec's. We care about hardware and not all hardware
> follows specifications.
>
> Please fix the exact thing you want to fix (and please provide a fixes
> tag).
I edit the TPM main spec, not the PTP. As I discover TPMs that don't
meet the spec, or where the spec has changed over time, I add
informative comments to guide developers.
If you know of TPM hardware that does not meet the PTP specification,
let me know the specifics. I can bring it to the PTP work group and try
to get comments added.
I do not need to know the TPM vendor. That information would not go
into the specification anyway.