From 9fea3696efceb8223f8e1121077763f1295cc65f Mon Sep 17 00:00:00 2001
From: John Keeping <john@metanate.com>
Date: Mon, 27 Mar 2023 12:01:10 +0100
Subject: [PATCH] rockchip: otp: fix misc_read() return values

The documentation for misc_read() says:

    Return: number of bytes read if OK (may be 0 if EOF), -ve on error

The Rockchip efuse driver implements this so it should return the number
of bytes read rather than zero on success.  Fix this so that the driver
follows the usual contract for read operations.

Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Jonas Karlman <jonas@kwiboo.se>
Signed-off-by: John Keeping <john@metanate.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
---
 drivers/misc/rockchip-otp.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/misc/rockchip-otp.c b/drivers/misc/rockchip-otp.c
index c19cd5ce62..4814e0e501 100644
--- a/drivers/misc/rockchip-otp.c
+++ b/drivers/misc/rockchip-otp.c
@@ -89,7 +89,7 @@ static int dump_otp(struct cmd_tbl *cmdtp, int flag,
 
 	for (i = 0; true; i += sizeof(data)) {
 		ret = misc_read(dev, i, &data, sizeof(data));
-		if (ret < 0)
+		if (ret <= 0)
 			return 0;
 
 		print_buffer(i, data, 1, sizeof(data), sizeof(data));
@@ -249,8 +249,10 @@ static int rockchip_otp_read(struct udevice *dev, int offset,
 
 	offset += data->offset;
 
-	if (data->block_size <= 1)
-		return data->read(dev, offset, buf, size);
+	if (data->block_size <= 1) {
+		ret = data->read(dev, offset, buf, size);
+		goto done;
+	}
 
 	block_start = offset / data->block_size;
 	block_offset = offset % data->block_size;
@@ -266,7 +268,9 @@ static int rockchip_otp_read(struct udevice *dev, int offset,
 		memcpy(buf, buffer + block_offset, size);
 
 	free(buffer);
-	return ret;
+
+done:
+	return ret < 0 ? ret : size;
 }
 
 static const struct misc_ops rockchip_otp_ops = {
-- 
2.39.5