From: Peter Huewe <peter.huewe@infineon.com>
To: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>,
<tpmdd-devel@lists.sourceforge.net>,
<linux-kernel@vger.kernel.org>, <peterhuewe@gmx.de>,
Christophe Ricard <christophe-h.ricard@st.com>,
"Peter Huewe" <peter.huewe@infineon.com>,
<stable@vger.kernel.org>,
Alexander Steffen <Alexander.Steffen@infineon.com>
Subject: [PATCH 3/5] tpm_tis_spi: Check correct byte for wait state indicator
Date: Thu, 16 Feb 2017 16:08:24 +0000 [thread overview]
Message-ID: <1487261306-2494-4-git-send-email-peter.huewe@infineon.com> (raw)
In-Reply-To: <1487261306-2494-1-git-send-email-peter.huewe@infineon.com>
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].
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>
---
drivers/char/tpm/tpm_tis_spi.c | 40 +++++++++++++++++++++-------------------
1 file changed, 21 insertions(+), 19 deletions(-)
diff --git a/drivers/char/tpm/tpm_tis_spi.c b/drivers/char/tpm/tpm_tis_spi.c
index d782b9974c14..16938e2253d2 100644
--- a/drivers/char/tpm/tpm_tis_spi.c
+++ b/drivers/char/tpm/tpm_tis_spi.c
@@ -60,7 +60,7 @@ static int tpm_tis_spi_transfer(struct tpm_tis_data *data, u32 addr, u8 len,
u8 *buffer, u8 direction)
{
struct tpm_tis_spi_phy *phy = to_tpm_tis_spi_phy(data);
- int ret, i;
+ int ret;
struct spi_message m;
struct spi_transfer spi_xfer = {
.tx_buf = phy->tx_buf,
@@ -85,25 +85,27 @@ static int tpm_tis_spi_transfer(struct tpm_tis_data *data, u32 addr, u8 len,
if (ret < 0)
goto exit;
- 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)
+ if ((phy->rx_buf[3] & 0x01) == 0) {
+ // handle SPI wait states
+ int i;
+
+ phy->tx_buf[0] = 0;
+
+ 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;
--
2.7.4
next prev parent reply other threads:[~2017-02-16 16:09 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-02-16 16:08 [PATCH 0/5] Fix whole native SPI TPM driver Peter Huewe
2017-02-16 16:08 ` [PATCH 1/5] tpm_tis_spi: Use single function to transfer data Peter Huewe
2017-02-24 12:54 ` Jarkko Sakkinen
2017-02-16 16:08 ` [PATCH 2/5] tpm_tis_spi: Abort transfer when too many wait states are signaled Peter Huewe
2017-02-17 5:04 ` Christophe Ricard
2017-02-24 12:55 ` Jarkko Sakkinen
2017-02-16 16:08 ` Peter Huewe [this message]
2017-02-17 5:09 ` [PATCH 3/5] tpm_tis_spi: Check correct byte for wait state indicator Christophe Ricard
2017-02-17 7:15 ` Peter Huewe
2017-02-24 12:57 ` Jarkko Sakkinen
2017-02-16 16:08 ` [PATCH 4/5] tpm_tis_spi: Remove limitation of transfers to MAX_SPI_FRAMESIZE bytes Peter Huewe
2017-02-16 17:27 ` kbuild test robot
2017-02-17 5:11 ` Christophe Ricard
2017-02-17 7:19 ` Peter Huewe
2017-02-24 11:55 ` Jarkko Sakkinen
2017-02-24 12:59 ` Jarkko Sakkinen
2017-02-22 21:19 ` [PATCH 0/5] Fix whole native SPI TPM driver Jarkko Sakkinen
2017-02-22 22:32 ` Peter Huewe
2017-02-24 15:15 ` Jarkko Sakkinen
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