[PATCH 10/14] tpm2: resend the command on TPM_RC_RETRY

[Gary Lin]

Sometimes TPM may return TPM_RC_RETRY for some reason, and the only
thing we can do is to send the command again. To avoid pending in the
while loop indefinitely, just try to send the command 3 times.

Signed-off-by: Gary Lin <glin@suse.com>
---
 grub-core/tpm2/tpm2.c | 33 ++++++++++++++++++++++++++++-----
 1 file changed, 28 insertions(+), 5 deletions(-)

diff --git a/grub-core/tpm2/tpm2.c b/grub-core/tpm2/tpm2.c
index 6c476ff31..bc1d797d4 100644
--- a/grub-core/tpm2/tpm2.c
+++ b/grub-core/tpm2/tpm2.c
@@ -25,11 +25,11 @@
 #include <grub/types.h>
 
 static TPM_RC
-grub_tpm2_submit_command (const TPMI_ST_COMMAND_TAG tag,
-                         const TPM_CC commandCode,
-                         TPM_RC *responseCode,
-                         const struct grub_tpm2_buffer *in,
-                         struct grub_tpm2_buffer *out)
+grub_tpm2_submit_command_real (const TPMI_ST_COMMAND_TAG tag,
+                              const TPM_CC commandCode,
+                              TPM_RC *responseCode,
+                              const struct grub_tpm2_buffer *in,
+                              struct grub_tpm2_buffer *out)
 {
   grub_err_t err;
   struct grub_tpm2_buffer buf;
@@ -75,6 +75,29 @@ grub_tpm2_submit_command (const TPMI_ST_COMMAND_TAG tag,
   return TPM_RC_SUCCESS;
 }
 
+static TPM_RC
+grub_tpm2_submit_command (const TPMI_ST_COMMAND_TAG tag,
+                         const TPM_CC commandCode,
+                         TPM_RC *responseCode,
+                         const struct grub_tpm2_buffer *in,
+                         struct grub_tpm2_buffer *out)
+{
+  TPM_RC err;
+  int retry_cnt = 0;
+
+  /* Catch TPM_RC_RETRY and send the command again */
+  do {
+    err = grub_tpm2_submit_command_real (tag, commandCode, responseCode,
+                                        in, out);
+    if (*responseCode != TPM_RC_RETRY)
+      break;
+
+    retry_cnt++;
+  } while (retry_cnt < 3);
+
+  return err;
+}
+
 TPM_RC
 TPM2_CreatePrimary (const TPMI_RH_HIERARCHY primaryHandle,
                    const TPMS_AUTH_COMMAND *authCommand,
-- 
2.35.3