Optimize performance of flash reads/writes

1) Smaller start delay for commands
2) Reads can use the entire 128 byte parameter space

This improves read speed from 350ms/64kb to 210ms/64kb.

BUG=none
TEST=ectool flashread 81920 81920 then compare with ec.A.bin

Change-Id: I53d460bace5f21db845a3f8ec681507fca0f7b0e
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/25562
Reviewed-by: Bill Richardson <wfrichar@chromium.org>

4 files changed, 18 insertions, 20 deletions

diff --git a/include/ec_commands.h b/include/ec_commands.h
index db84020a4d..6690522e88 100644
--- a/include/ec_commands.h
+++ b/include/ec_commands.h
@@ -253,9 +253,6 @@ struct ec_params_board_version {
 /*****************************************************************************/
 /* Flash commands */
 
-/* Maximum bytes that can be read/written in a single command */
-#define EC_FLASH_SIZE_MAX 64
-
 /* Get flash info */
 #define EC_CMD_FLASH_INFO 0x10
 struct ec_response_flash_info {
@@ -279,7 +276,7 @@ struct ec_params_flash_read {
 	uint32_t size;     /* Size to read in bytes */
 } __attribute__ ((packed));
 struct ec_response_flash_read {
-	uint8_t data[EC_FLASH_SIZE_MAX];
+	uint8_t data[EC_PARAM_SIZE];
 } __attribute__ ((packed));
 
 /* Write flash */
@@ -287,7 +284,8 @@ struct ec_response_flash_read {
 struct ec_params_flash_write {
 	uint32_t offset;   /* Byte offset to write */
 	uint32_t size;     /* Size to write in bytes */
-	uint8_t data[EC_FLASH_SIZE_MAX];
+	uint8_t data[64];  /* Could really use EC_PARAM_SIZE - 8, but tidiest
+			    * to use a power of 2 so writes stay aligned. */
 } __attribute__ ((packed));
 
 /* Erase flash */
diff --git a/util/burn_my_ec.c b/util/burn_my_ec.c
index 27a921123a..cb8ead87ac 100644
--- a/util/burn_my_ec.c
+++ b/util/burn_my_ec.c
@@ -87,9 +87,9 @@ int flash_partition(enum ec_current_image part, const uint8_t *payload,
 	printf("Writing partition %s : 0x%x bytes at 0x%08x\n",
 	       part_name[part], size, offset);
 	/* Write data in chunks */
-	for (i = 0; i < size; i += EC_FLASH_SIZE_MAX) {
+	for (i = 0; i < size; i += sizeof(wr_req.data)) {
 		wr_req.offset = offset + i;
-		wr_req.size = MIN(size - i, EC_FLASH_SIZE_MAX);
+		wr_req.size = MIN(size - i, sizeof(wr_req.data));
 		memcpy(wr_req.data, payload + i, wr_req.size);
 		res = ec_command(EC_CMD_FLASH_WRITE, &wr_req, sizeof(wr_req),
 				 NULL, 0);
@@ -102,9 +102,9 @@ int flash_partition(enum ec_current_image part, const uint8_t *payload,
 	printf("Verifying partition %s : 0x%x bytes at 0x%08x\n",
 	       part_name[part], size, offset);
 	/* Read data in chunks */
-	for (i = 0; i < size; i += EC_FLASH_SIZE_MAX) {
+	for (i = 0; i < size; i += sizeof(rd_resp.data)) {
 		rd_req.offset = offset + i;
-		rd_req.size = MIN(size - i, EC_FLASH_SIZE_MAX);
+		rd_req.size = MIN(size - i, sizeof(rd_resp.data));
 		res = ec_command(EC_CMD_FLASH_READ, &rd_req, sizeof(rd_req),
 				 &rd_resp, sizeof(rd_resp));
 		if (res) {
diff --git a/util/comm-lpc.c b/util/comm-lpc.c
index 8b42763753..4f3aae3912 100644
--- a/util/comm-lpc.c
+++ b/util/comm-lpc.c
@@ -13,7 +13,7 @@
 #include "ec_commands.h"
 
 
-#define INITIAL_UDELAY 10    /* 10 us */
+#define INITIAL_UDELAY 5     /* 5 us */
 #define MAXIMUM_UDELAY 10000 /* 10 ms */
 
 int comm_init(void)
@@ -31,13 +31,13 @@ int comm_init(void)
 	 * If they all are 0xff, then very possible you cannot access GEC. */
 	byte &= inb(EC_LPC_ADDR_USER_CMD);
 	byte &= inb(EC_LPC_ADDR_USER_DATA);
-	for (i = 0; i < EC_FLASH_SIZE_MAX /* big enough */; ++i)
+	for (i = 0; i < EC_PARAM_SIZE && byte == 0xff; ++i)
 		byte &= inb(EC_LPC_ADDR_USER_PARAM + i);
 	if (byte == 0xff) {
 		fprintf(stderr, "Port 0x%x,0x%x,0x%x-0x%x are all 0xFF.\n",
 			EC_LPC_ADDR_USER_CMD, EC_LPC_ADDR_USER_DATA,
 			EC_LPC_ADDR_USER_PARAM,
-			EC_LPC_ADDR_USER_PARAM + EC_FLASH_SIZE_MAX - 1);
+			EC_LPC_ADDR_USER_PARAM + EC_PARAM_SIZE - 1);
 		fprintf(stderr, "Very likely this board doesn't have GEC.\n");
 		return -4;
 	}
@@ -64,8 +64,9 @@ static int wait_for_ec(int status_addr, int timeout_usec)
 		if (!(inb(status_addr) & EC_LPC_STATUS_BUSY_MASK))
 			return 0;
 
-		/* Increase the delay interval */
-		delay = MIN(delay * 2, MAXIMUM_UDELAY);
+		/* Increase the delay interval after a few rapid checks */
+		if (i > 20)
+			delay = MIN(delay * 2, MAXIMUM_UDELAY);
 	}
 	return -1;  /* Timeout */
 }
diff --git a/util/ectool.c b/util/ectool.c
index 5f10d35b80..6942f9f9ab 100644
--- a/util/ectool.c
+++ b/util/ectool.c
@@ -413,9 +413,9 @@ int cmd_flash_read(int argc, char *argv[])
 	}
 
 	/* Read data in chunks */
-	for (i = 0; i < size; i += EC_FLASH_SIZE_MAX) {
+	for (i = 0; i < size; i += sizeof(r.data)) {
 		p.offset = offset + i;
-		p.size = MIN(size - i, EC_FLASH_SIZE_MAX);
+		p.size = MIN(size - i, sizeof(r.data));
 		rv = ec_command(EC_CMD_FLASH_READ,
 				&p, sizeof(p), &r, sizeof(r));
 		if (rv) {
@@ -463,12 +463,11 @@ int cmd_flash_write(int argc, char *argv[])
 	printf("Writing to offset %d...\n", offset);
 
 	/* Write data in chunks */
-	for (i = 0; i < size; i += EC_FLASH_SIZE_MAX) {
+	for (i = 0; i < size; i += sizeof(p.data)) {
 		p.offset = offset + i;
-		p.size = MIN(size - i, EC_FLASH_SIZE_MAX);
+		p.size = MIN(size - i, sizeof(p.data));
 		memcpy(p.data, buf + i, p.size);
-		rv = ec_command(EC_CMD_FLASH_WRITE,
-				&p, sizeof(p), NULL, 0);
+		rv = ec_command(EC_CMD_FLASH_WRITE, &p, sizeof(p), NULL, 0);
 		if (rv) {
 			fprintf(stderr, "Write error at offset %d\n", i);
 			free(buf);