This is a note to let you know that I've just added the patch titled tpm_tis_spi: Check correct byte for wait state indicator to the 4.11-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: tpm_tis_spi-check-correct-byte-for-wait-state-indicator.patch and it can be found in the queue-4.11 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From e110cc69dc2ad679d6d478df636b99b14e6fbbc9 Mon Sep 17 00:00:00 2001 From: Peter Huewe <peter.huewe@xxxxxxxxxxxx> Date: Thu, 2 Mar 2017 13:03:13 +0000 Subject: tpm_tis_spi: Check correct byte for wait state indicator From: Peter Huewe <peter.huewe@xxxxxxxxxxxx> commit e110cc69dc2ad679d6d478df636b99b14e6fbbc9 upstream. Wait states are signaled in the last byte received from the TPM in response to the header, not the first byte. Check rx_buf[3] instead of rx_buf[0]. Fixes: 0edbfea537d1 ("tpm/tpm_tis_spi: Add support for spi phy") Signed-off-by: Alexander Steffen <Alexander.Steffen@xxxxxxxxxxxx> Signed-off-by: Peter Huewe <peter.huewe@xxxxxxxxxxxx> Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx> Tested-by: Benoit Houyere <benoit.houyere@xxxxxx> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/char/tpm/tpm_tis_spi.c | 34 +++++++++++++++++----------------- 1 file changed, 17 insertions(+), 17 deletions(-) --- a/drivers/char/tpm/tpm_tis_spi.c +++ b/drivers/char/tpm/tpm_tis_spi.c @@ -85,25 +85,25 @@ static int tpm_tis_spi_transfer(struct t if (ret < 0) goto exit; - phy->tx_buf[0] = 0; + if ((phy->rx_buf[3] & 0x01) == 0) { + // handle SPI wait states + phy->tx_buf[0] = 0; - /* According to TCG PTP specification, if there is no TPM present at - * all, then the design has a weak pull-up on MISO. If a TPM is not - * present, a pull-up on MISO means that the SB controller sees a 1, - * and will latch in 0xFF on the read. - */ - for (i = 0; (phy->rx_buf[0] & 0x01) == 0 && i < TPM_RETRY; i++) { - spi_xfer.len = 1; - spi_message_init(&m); - spi_message_add_tail(&spi_xfer, &m); - ret = spi_sync_locked(phy->spi_device, &m); - if (ret < 0) - goto exit; - } + for (i = 0; i < TPM_RETRY; i++) { + spi_xfer.len = 1; + spi_message_init(&m); + spi_message_add_tail(&spi_xfer, &m); + ret = spi_sync_locked(phy->spi_device, &m); + if (ret < 0) + goto exit; + if (phy->rx_buf[0] & 0x01) + break; + } - if (i == TPM_RETRY) { - ret = -ETIMEDOUT; - goto exit; + if (i == TPM_RETRY) { + ret = -ETIMEDOUT; + goto exit; + } } spi_xfer.cs_change = 0; Patches currently in stable-queue which might be from peter.huewe@xxxxxxxxxxxx are queue-4.11/tpm_tis_spi-abort-transfer-when-too-many-wait-states-are-signaled.patch queue-4.11/tpm_tis_spi-remove-limitation-of-transfers-to-max_spi_framesize-bytes.patch queue-4.11/tpm_tis_core-choose-appropriate-timeout-for-reading-burstcount.patch queue-4.11/tpm_tis_spi-add-small-delay-after-last-transfer.patch queue-4.11/tpm_tis_spi-check-correct-byte-for-wait-state-indicator.patch queue-4.11/tpm_tis_spi-use-single-function-to-transfer-data.patch