linux-kernel - [PATCH v1 3/5] char: tpm: rewrite "tpm_tis_req

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Date:   Sun, 10 Nov 2019 18:21:35 +0200
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,
        ayna@...ux.vnet.ibm.com, Dan.Morav@...oton.com,
        oren.tanami@...oton.com, shmulik.hagar@...oton.com,
        amir.mizinski@...oton.com, Amir Mizinski <amirmizi6@...il.com>
Subject: [PATCH v1 3/5] char: tpm: 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.
also only cmdReady bit need to be compared instead of the full lower status register byte.

Signed-off-by: Amir Mizinski <amirmizi6@...il.com>
---
 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));
-	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