summaryrefslogtreecommitdiffstats
path: root/drivers/char
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/char')
-rw-r--r--drivers/char/tpm/tpm.c31
-rw-r--r--drivers/char/tpm/tpm.h3
2 files changed, 30 insertions, 4 deletions
diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c
index 0d2e82f95577..7c3b3dcbfbc8 100644
--- a/drivers/char/tpm/tpm.c
+++ b/drivers/char/tpm/tpm.c
@@ -1337,7 +1337,7 @@ int tpm_pm_suspend(struct device *dev)
{
struct tpm_chip *chip = dev_get_drvdata(dev);
struct tpm_cmd_t cmd;
- int rc;
+ int rc, try;
u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
@@ -1355,9 +1355,32 @@ int tpm_pm_suspend(struct device *dev)
}
/* now do the actual savestate */
- cmd.header.in = savestate_header;
- rc = transmit_cmd(chip, &cmd, SAVESTATE_RESULT_SIZE,
- "sending savestate before suspend");
+ for (try = 0; try < TPM_RETRY; try++) {
+ cmd.header.in = savestate_header;
+ rc = transmit_cmd(chip, &cmd, SAVESTATE_RESULT_SIZE, NULL);
+
+ /*
+ * If the TPM indicates that it is too busy to respond to
+ * this command then retry before giving up. It can take
+ * several seconds for this TPM to be ready.
+ *
+ * This can happen if the TPM has already been sent the
+ * SaveState command before the driver has loaded. TCG 1.2
+ * specification states that any communication after SaveState
+ * may cause the TPM to invalidate previously saved state.
+ */
+ if (rc != TPM_WARN_RETRY)
+ break;
+ msleep(TPM_TIMEOUT_RETRY);
+ }
+
+ if (rc)
+ dev_err(chip->dev,
+ "Error (%d) sending savestate before suspend\n", rc);
+ else if (try > 0)
+ dev_warn(chip->dev, "TPM savestate took %dms\n",
+ try * TPM_TIMEOUT_RETRY);
+
return rc;
}
EXPORT_SYMBOL_GPL(tpm_pm_suspend);
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 81b52015f669..0770d1d79366 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -32,10 +32,12 @@ enum tpm_const {
TPM_MINOR = 224, /* officially assigned */
TPM_BUFSIZE = 4096,
TPM_NUM_DEVICES = 256,
+ TPM_RETRY = 50, /* 5 seconds */
};
enum tpm_timeout {
TPM_TIMEOUT = 5, /* msecs */
+ TPM_TIMEOUT_RETRY = 100 /* msecs */
};
/* TPM addresses */
@@ -44,6 +46,7 @@ enum tpm_addr {
TPM_ADDR = 0x4E,
};
+#define TPM_WARN_RETRY 0x800
#define TPM_WARN_DOING_SELFTEST 0x802
#define TPM_ERR_DEACTIVATED 0x6
#define TPM_ERR_DISABLED 0x7
OpenPOWER on IntegriCloud