linux-kernel - [PATCH v6 3/7] tpm: tpm_tis: rewrite "tpm_tis_req

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Message-Id: <20200407162044.168890-4-amirmizi6@gmail.com>
Date:   Tue,  7 Apr 2020 19:20:40 +0300
From:   amirmizi6@...il.com
To:     Eyal.Cohen@...oton.com, jarkko.sakkinen@...ux.intel.com,
        oshrialkoby85@...il.com, alexander.steffen@...ineon.com,
        robh+dt@...nel.org, mark.rutland@....com, peterhuewe@....de,
        jgg@...pe.ca, arnd@...db.de, gregkh@...uxfoundation.org
Cc:     devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-integrity@...r.kernel.org, oshri.alkoby@...oton.com,
        tmaimon77@...il.com, gcwilson@...ibm.com, kgoldman@...ibm.com,
        Dan.Morav@...oton.com, oren.tanami@...oton.com,
        shmulik.hager@...oton.com, amir.mizinski@...oton.com,
        Amir Mizinski <amirmizi6@...il.com>
Subject: [PATCH v6 3/7] tpm: tpm_tis: rewrite "tpm_tis_req_canceled()"

From: Amir Mizinski <amirmizi6@...il.com>

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.
So i'm removing the case for "TPM_VID_WINBOND" since we have no need for it

Also default comparison is wrong. only cmdReady bit need to be compared
instead of the full lower status register byte.

Fixes: 1f86605 (tpm: Fix cancellation of TPM commands (polling mode))
Signed-off-by: Amir Mizinski <amirmizi6@...il.com>
---
 drivers/char/tpm/tpm_tis_core.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index 6c4f232..453d7ef 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -713,13 +713,10 @@ 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);
 	}
 }
 
-- 
2.7.4