Messages in this thread Patch in this message | | | From | wanghongzhe <> | Subject | [PATCH v2] tpm_tis_spi_main: set cs_change = 0 when timesout | Date | Fri, 5 Feb 2021 16:41:09 +0800 |
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when i reach TPM_RETRY, the cs cannot change back to 'high'. So the TPM chips thinks 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 error
Signed-off-by: wanghongzhe <wanghongzhe@huawei.com> --- 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
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