[coreboot-gerrit] New patch to review for coreboot: tpm: use 4 byte quantities when retrieving firmware version

[Martin Roth (martinroth@google.com)]

Martin Roth (martinroth at google.com) just uploaded a new patch set to gerrit, which you can find at https://review.coreboot.org/15580

-gerrit

commit 500837c19b2e49d87798aee54af3df10e8e32705
Author: Vadim Bendebury <vbendeb at chromium.org>
Date:   Mon Jun 27 19:05:41 2016 -0700

    tpm: use 4 byte quantities when retrieving firmware version
    
    The CR50 device is capable of reporting its firmware version in 4 byte
    quantities, but the recently introduced code retrieves the version one
    byte at a time.
    
    With this fix the version is retrieved in 4 byte chunks.
    
    BRANCH=none
    BUG=none
    TEST=the version is still reported properly, as reported by the AP
         firmware console log:
    
    localhost ~ # grep cr50 /sys/firmware/log
    Firmware version: cr50_v1.1.4804-c64cf24
    localhost ~ #
    
    Change-Id: Ia7461b758be2287e69a1ba6f038c257f50338199
    Signed-off-by: Martin Roth <martinroth at chromium.org>
    Original-Commit-Id: 3111537e7b66d8507b6608ef665e4cde76403818
    Original-Change-Id: I04116881a30001e35e989e51ec1567263f9149a6
    Original-Signed-off-by: Vadim Bendebury <vbendeb at chromium.org>
    Original-Reviewed-on: https://chromium-review.googlesource.com/356542
    Original-Reviewed-by: Andrey Pronin <apronin at chromium.org>
---
 src/drivers/spi/tpm/tpm.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/drivers/spi/tpm/tpm.c b/src/drivers/spi/tpm/tpm.c
index 1b43bfb..4de62d9 100644
--- a/src/drivers/spi/tpm/tpm.c
+++ b/src/drivers/spi/tpm/tpm.c
@@ -359,7 +359,8 @@ int tpm2_init(struct spi_slave *spi_if)
 	/* Let's report device FW version if available. */
 	if (tpm_info.vendor_id == 0x1ae0) {
 		int chunk_count = 0;
-		char vstr[sizeof(cmd) + 1];	/* room for 4 chars + zero */
+		uint32_t chunk = 0;
+		char vstr[sizeof(chunk) + 1];	/* room for 4 chars + zero */
 
 		printk(BIOS_INFO, "Firmware version: ");
 
@@ -367,12 +368,12 @@ int tpm2_init(struct spi_slave *spi_if)
 		 * Does not really matter what's written, this just makes sure
 		 * the version is reported from the beginning.
 		 */
-		tpm2_write_reg(TPM_FW_VER, &cmd, sizeof(cmd));
+		tpm2_write_reg(TPM_FW_VER, &chunk, sizeof(chunk));
 
 		/* Print it out in 4 byte chunks. */
 		vstr[sizeof(vstr) - 1] = 0;
 		do {
-			tpm2_read_reg(TPM_FW_VER, vstr, sizeof(cmd));
+			tpm2_read_reg(TPM_FW_VER, vstr, sizeof(chunk));
 			printk(BIOS_INFO, "%s", vstr);
 
 			/*
@@ -381,7 +382,7 @@ int tpm2_init(struct spi_slave *spi_if)
 			 * This is likely result in one extra printk()
 			 * invocation with an empty string, not a big deal.
 			 */
-		} while (vstr[0] && (chunk_count++ < (200 / sizeof(cmd))));
+		} while (vstr[0] && (chunk_count++ < (200 / sizeof(chunk))));
 
 		printk(BIOS_INFO, "\n");
 	}