[PATCH v1 1/1] [SRU][F:linux-bluefield][PATCH 1/1] UBUNTU: SAUCE: Fix the rshim logging buffer full/wraparound issue

[Liming Sun]

Buglink: https://bugs.launchpad.net/bugs/1919847

This commit fixes the full/wraparound issue of the rshim logging
buffer. When checking the total length of the message, it should
count in the header (one 8-Byte word) as well.

Signed-off-by: Liming Sun <limings at nvidia.com>
---
 drivers/platform/mellanox/mlx-bootctl.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/platform/mellanox/mlx-bootctl.c b/drivers/platform/mellanox/mlx-bootctl.c
index 1bc0c7b..7ec7c9a 100644
--- a/drivers/platform/mellanox/mlx-bootctl.c
+++ b/drivers/platform/mellanox/mlx-bootctl.c
@@ -510,9 +510,9 @@ static ssize_t rsh_log_store(struct device_driver *drv, const char *buf,
 	/* Calculate how many words are available. */
 	num = (size + sizeof(u64) - 1) / sizeof(u64);
 	idx = readq(rsh_scratch_buf_ctl);
-	if (idx + num >= RSH_SCRATCH_BUF_CTL_IDX_MAX)
-		num = RSH_SCRATCH_BUF_CTL_IDX_MAX - idx;
-	if (!num)
+	if (idx + num + 1 >= RSH_SCRATCH_BUF_CTL_IDX_MAX)
+		num = RSH_SCRATCH_BUF_CTL_IDX_MAX - idx - 1;
+	if (num <= 0)
 		goto done;
 
 	/* Write Header. */
-- 
1.8.3.1