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 062799e04f04e0a928619e4e71323737f00addb7..639614f2d415a400f118287ed28d2caf17e2742c 100644 (file)
--- 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;