[PATCH ethtool-next 1/7] cmis: Fix CLEI code parsing

[Ido Schimmel <idosch@idosch.org>]

From: Ido Schimmel <idosch@nvidia.com>

In CMIS, unlike SFF-8636, there is no presence indication for the CLEI
code (Common Language Equipment Identification) field. The field is
always present, but might not be supported. In which case, "a value of
all ASCII 20h (spaces) shall be entered".

Therefore, remove the erroneous check which seems to be influenced from
SFF-8636 and only print the string if it is supported and has a non-zero
length.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
---
 cmis.c | 8 +++++---
 cmis.h | 3 +--
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/cmis.c b/cmis.c
index 1a91e798e4b8..2a48c1a1d56a 100644
--- a/cmis.c
+++ b/cmis.c
@@ -307,6 +307,8 @@ static void cmis_show_link_len(const __u8 *id)
  */
 static void cmis_show_vendor_info(const __u8 *id)
 {
+	const char *clei = (const char *)(id + CMIS_CLEI_START_OFFSET);
+
 	sff_show_ascii(id, CMIS_VENDOR_NAME_START_OFFSET,
 		       CMIS_VENDOR_NAME_END_OFFSET, "Vendor name");
 	cmis_show_oui(id);
@@ -319,9 +321,9 @@ static void cmis_show_vendor_info(const __u8 *id)
 	sff_show_ascii(id, CMIS_DATE_YEAR_OFFSET,
 		       CMIS_DATE_VENDOR_LOT_OFFSET + 1, "Date code");
 
-	if (id[CMIS_CLEI_PRESENT_BYTE] & CMIS_CLEI_PRESENT_MASK)
-		sff_show_ascii(id, CMIS_CLEI_START_OFFSET,
-			       CMIS_CLEI_END_OFFSET, "CLEI code");
+	if (strlen(clei) && strcmp(clei, CMIS_CLEI_BLANK))
+		sff_show_ascii(id, CMIS_CLEI_START_OFFSET, CMIS_CLEI_END_OFFSET,
+			       "CLEI code");
 }
 
 void qsfp_dd_show_all(const __u8 *id)
diff --git a/cmis.h b/cmis.h
index 78ee1495bc33..d365252baa48 100644
--- a/cmis.h
+++ b/cmis.h
@@ -34,10 +34,9 @@
 #define CMIS_DATE_VENDOR_LOT_OFFSET		0xBC
 
 /* CLEI Code (Page 0) */
-#define CMIS_CLEI_PRESENT_BYTE			0x02
-#define CMIS_CLEI_PRESENT_MASK			0x20
 #define CMIS_CLEI_START_OFFSET			0xBE
 #define CMIS_CLEI_END_OFFSET			0xC7
+#define CMIS_CLEI_BLANK				"          "
 
 /* Cable assembly length */
 #define CMIS_CBL_ASM_LEN_OFFSET			0xCA
-- 
2.31.1