File ethtool-support-combinations-of-FEC-modes.patch of Package ethtool

From: Edward Cree <ecree@solarflare.com>
Date: Wed, 5 Sep 2018 18:54:57 +0100
Subject: ethtool: support combinations of FEC modes
Patch-mainline: v4.19?
Git-commit: d4b9f3fc945d6c188dced991d57f15650a8f90a3
References: fate#326122 bsc#1105557

Of the three drivers that currently support FEC configuration, two (sfc
 and cxgb4[vf]) accept configurations with more than one bit set in the
 feccmd.fec bitmask.  (The precise semantics of these combinations vary.)
Thus, this patch adds the ability to specify such combinations through a
 comma-separated list of FEC modes in the 'encoding' argument on the
 command line.

Also adds --set-fec tests to test-cmdline.c, and corrects the man page
 (the encoding argument is not optional) while updating it.

Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Acked-by: Michal Kubecek <mkubecek@suse.cz>

---
 ethtool.8.in   | 11 ++++++++---
 ethtool.c      | 50 +++++++++++++++++++++++++++++++++++++++-----------
 test-cmdline.c |  9 +++++++++
 3 files changed, 56 insertions(+), 14 deletions(-)

diff --git a/ethtool.8.in b/ethtool.8.in
index 00e5e5b2dc05..07ad69edcf64 100644
--- a/ethtool.8.in
+++ b/ethtool.8.in
@@ -365,7 +365,8 @@ ethtool \- query or control network driver and hardware settings
 .HP
 .B ethtool \-\-set\-fec
 .I devname
-.B4 encoding auto off rs baser
+.B encoding
+.BR auto | off | rs | baser [ , ...]
 .
 .\" Adjust lines (i.e. full justification) and hyphenate.
 .ad
@@ -1053,8 +1054,12 @@ current FEC mode, the driver or firmware must take the link down
 administratively and report the problem in the system logs for users to correct.
 .RS 4
 .TP
-.A4 encoding auto off rs baser
-Sets the FEC encoding for the device.
+.BR encoding\ auto | off | rs | baser [ , ...]
+
+Sets the FEC encoding for the device.  Combinations of options are specified as
+e.g.
+.B auto,rs
+; the semantics of such combinations vary between drivers.
 .TS
 nokeep;
 lB	l.
diff --git a/ethtool.c b/ethtool.c
index d284890779ea..a5c20337fa4c 100644
--- a/ethtool.c
+++ b/ethtool.c
@@ -4873,21 +4873,49 @@ static int do_set_phy_tunable(struct cmd_context *ctx)
 }
 
 static int fecmode_str_to_type(const char *str)
+{
+	if (!strcasecmp(str, "auto"))
+		return ETHTOOL_FEC_AUTO;
+	if (!strcasecmp(str, "off"))
+		return ETHTOOL_FEC_OFF;
+	if (!strcasecmp(str, "rs"))
+		return ETHTOOL_FEC_RS;
+	if (!strcasecmp(str, "baser"))
+		return ETHTOOL_FEC_BASER;
+
+	return 0;
+}
+
+/* Takes a comma-separated list of FEC modes, returns the bitwise OR of their
+ * corresponding ETHTOOL_FEC_* constants.
+ * Accepts repetitions (e.g. 'auto,auto') and trailing comma (e.g. 'off,').
+ */
+static int parse_fecmode(const char *str)
 {
 	int fecmode = 0;
+	char buf[6];
 
 	if (!str)
-		return fecmode;
-
-	if (!strcasecmp(str, "auto"))
-		fecmode |= ETHTOOL_FEC_AUTO;
-	else if (!strcasecmp(str, "off"))
-		fecmode |= ETHTOOL_FEC_OFF;
-	else if (!strcasecmp(str, "rs"))
-		fecmode |= ETHTOOL_FEC_RS;
-	else if (!strcasecmp(str, "baser"))
-		fecmode |= ETHTOOL_FEC_BASER;
+		return 0;
+	while (*str) {
+		size_t next;
+		int mode;
 
+		next = strcspn(str, ",");
+		if (next >= 6) /* Bad mode, longest name is 5 chars */
+			return 0;
+		/* Copy into temp buffer and nul-terminate */
+		memcpy(buf, str, next);
+		buf[next] = 0;
+		mode = fecmode_str_to_type(buf);
+		if (!mode) /* Bad mode encountered */
+			return 0;
+		fecmode |= mode;
+		str += next;
+		/* Skip over ',' (but not nul) */
+		if (*str)
+			str++;
+	}
 	return fecmode;
 }
 
@@ -4935,7 +4963,7 @@ static int do_sfec(struct cmd_context *ctx)
 	if (!fecmode_str)
 		exit_bad_args();
 
-	fecmode = fecmode_str_to_type(fecmode_str);
+	fecmode = parse_fecmode(fecmode_str);
 	if (!fecmode)
 		exit_bad_args();
 
diff --git a/test-cmdline.c b/test-cmdline.c
index a94edea51596..9c51ccada19d 100644
--- a/test-cmdline.c
+++ b/test-cmdline.c
@@ -266,6 +266,15 @@ static struct test_case {
 	{ 0, "--set-eee devname tx-timer 42 advertise 0x4321" },
 	{ 1, "--set-eee devname tx-timer foo" },
 	{ 1, "--set-eee devname advertise foo" },
+	{ 1, "--set-fec devname" },
+	{ 0, "--set-fec devname encoding auto" },
+	{ 0, "--set-fec devname encoding off," },
+	{ 0, "--set-fec devname encoding baser,rs" },
+	{ 0, "--set-fec devname encoding auto,auto," },
+	{ 1, "--set-fec devname encoding foo" },
+	{ 1, "--set-fec devname encoding auto,foo" },
+	{ 1, "--set-fec devname encoding auto,," },
+	{ 1, "--set-fec devname auto" },
 	/* can't test --set-priv-flags yet */
 	{ 0, "-h" },
 	{ 0, "--help" },
-- 
2.19.1