From: Peter Huewe <peter.huewe@infineon.com>
Date: Thu, 2 Mar 2017 13:03:12 +0000 (+0000)
Subject: tpm_tis_spi: Abort transfer when too many wait states are signaled
X-Git-Tag: v4.12-rc1~123^2~35
X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=975094ddc369a32f27210248bdd9bbd153061b00;p=linux.git

tpm_tis_spi: Abort transfer when too many wait states are signaled

Abort the transfer with ETIMEDOUT when the TPM signals more than
TPM_RETRY wait states. Continuing with the transfer in this state
will only lead to arbitrary failures in other parts of the code.

Cc: <stable@vger.kernel.org>
Fixes: 0edbfea537d1 ("tpm/tpm_tis_spi: Add support for spi phy")
Signed-off-by: Alexander Steffen <Alexander.Steffen@infineon.com>
Signed-off-by: Peter Huewe <peter.huewe@infineon.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Benoit Houyere <benoit.houyere@st.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
---

diff --git a/drivers/char/tpm/tpm_tis_spi.c b/drivers/char/tpm/tpm_tis_spi.c
index 062799e04f04..639614f2d415 100644
--- a/drivers/char/tpm/tpm_tis_spi.c
+++ b/drivers/char/tpm/tpm_tis_spi.c
@@ -101,6 +101,11 @@ static int tpm_tis_spi_transfer(struct tpm_tis_data *data, u32 addr, u16 len,
 			goto exit;
 	}
 
+	if (i == TPM_RETRY) {
+		ret = -ETIMEDOUT;
+		goto exit;
+	}
+
 	spi_xfer.cs_change = 0;
 	spi_xfer.len = len;