The cs cannot change back to 'high' when the count is
TPM_RETRY. So the TPM chips thought this communication
is not over. And next times communication cannot be
effective because the communications mixed up with the
last time.
v1 -> v2:
- fix spi_xfer.cs_change to spi_xfer->cs_change
Signed-off-by: wanghongzhe <wanghongzhe@xxxxxxxxxx>
---
drivers/char/tpm/tpm_tis_spi_main.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/drivers/char/tpm/tpm_tis_spi_main.c b/drivers/char/tpm/tpm_tis_spi_main.c
index 3856f6ebcb34..6c52cbb28881 100644
--- a/drivers/char/tpm/tpm_tis_spi_main.c
+++ b/drivers/char/tpm/tpm_tis_spi_main.c
@@ -64,8 +64,18 @@ static int tpm_tis_spi_flow_control(struct tpm_tis_spi_phy *phy,
break;
}
- if (i == TPM_RETRY)
+ if (i == TPM_RETRY) {
+ /* change back to 'high',
+ * So the TPM chips thinks the last communication
+ * is done.
+ */
+ spi_xfer->cs_change = 0;
+ spi_xfer->len = 1;
+ spi_message_init(&m);
+ spi_message_add_tail(spi_xfer, &m);
+ ret = spi_sync_locked(phy->spi_device, &m);
return -ETIMEDOUT;
+ }
}
return 0;
--
2.19.1
