[PATCH 4.9 012/164] tpm_tis_spi: Abort transfer when too many wait states are signaled

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Peter Huewe <peter.hu...@infineon.com>

commit 975094ddc369a32f27210248bdd9bbd153061b00 upstream.

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.

Fixes: 0edbfea537d1 ("tpm/tpm_tis_spi: Add support for spi phy")
Signed-off-by: Alexander Steffen <alexander.stef...@infineon.com>
Signed-off-by: Peter Huewe <peter.hu...@infineon.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakki...@linux.intel.com>
Tested-by: Benoit Houyere <benoit.houy...@st.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakki...@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 drivers/char/tpm/tpm_tis_spi.c |    5 +++++
 1 file changed, 5 insertions(+)

--- a/drivers/char/tpm/tpm_tis_spi.c
+++ b/drivers/char/tpm/tpm_tis_spi.c
@@ -102,6 +102,11 @@ static int tpm_tis_spi_transfer(struct t
                        goto exit;
        }
 
+       if (i == TPM_RETRY) {
+               ret = -ETIMEDOUT;
+               goto exit;
+       }
+
        spi_xfer.cs_change = 0;
        spi_xfer.len = len;