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* [PATCH net-next 1/5 v2] net: gemini: Look up L3 maxlen from table
@ 2018-07-04 18:33 Linus Walleij
  2018-07-04 18:33 ` [PATCH net-next 2/5 v2] net: gemini: Improve connection prints Linus Walleij
                   ` (4 more replies)
  0 siblings, 5 replies; 10+ messages in thread
From: Linus Walleij @ 2018-07-04 18:33 UTC (permalink / raw)
  To: netdev, David S . Miller, Michał Mirosław
  Cc: Janos Laube, Paulius Zaleckas, linux-arm-kernel, Hans Ulli Kroll,
	Florian Fainelli, Linus Walleij

The code to calculate the hardware register enumerator
for the maximum L3 length isn't entirely simple to read.
Use the existing defines and rewrite the function into a
table look-up.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
ChangeLog v1->v2:
- No changes, just resending with the rest.
---
 drivers/net/ethernet/cortina/gemini.c | 61 ++++++++++++++++++++-------
 1 file changed, 46 insertions(+), 15 deletions(-)

diff --git a/drivers/net/ethernet/cortina/gemini.c b/drivers/net/ethernet/cortina/gemini.c
index 6d7404f66f84..8fc31723f700 100644
--- a/drivers/net/ethernet/cortina/gemini.c
+++ b/drivers/net/ethernet/cortina/gemini.c
@@ -401,26 +401,57 @@ static int gmac_setup_phy(struct net_device *netdev)
 	return 0;
 }
 
-static int gmac_pick_rx_max_len(int max_l3_len)
-{
-	/* index = CONFIG_MAXLEN_XXX values */
-	static const int max_len[8] = {
-		1536, 1518, 1522, 1542,
-		9212, 10236, 1518, 1518
-	};
-	int i, n = 5;
+/* The maximum frame length is not logically enumerated in the
+ * hardware, so we do a table lookup to find the applicable max
+ * frame length.
+ */
+struct gmac_max_framelen {
+	unsigned int max_l3_len;
+	u8 val;
+};
 
-	max_l3_len += ETH_HLEN + VLAN_HLEN;
+static const struct gmac_max_framelen gmac_maxlens[] = {
+	{
+		.max_l3_len = 1518,
+		.val = CONFIG0_MAXLEN_1518,
+	},
+	{
+		.max_l3_len = 1522,
+		.val = CONFIG0_MAXLEN_1522,
+	},
+	{
+		.max_l3_len = 1536,
+		.val = CONFIG0_MAXLEN_1536,
+	},
+	{
+		.max_l3_len = 1542,
+		.val = CONFIG0_MAXLEN_1542,
+	},
+	{
+		.max_l3_len = 9212,
+		.val = CONFIG0_MAXLEN_9k,
+	},
+	{
+		.max_l3_len = 10236,
+		.val = CONFIG0_MAXLEN_10k,
+	},
+};
+
+static int gmac_pick_rx_max_len(unsigned int max_l3_len)
+{
+	const struct gmac_max_framelen *maxlen;
+	int maxtot;
+	int i;
 
-	if (max_l3_len > max_len[n])
-		return -1;
+	maxtot = max_l3_len + ETH_HLEN + VLAN_HLEN;
 
-	for (i = 0; i < 5; i++) {
-		if (max_len[i] >= max_l3_len && max_len[i] < max_len[n])
-			n = i;
+	for (i = 0; i < ARRAY_SIZE(gmac_maxlens); i++) {
+		maxlen = &gmac_maxlens[i];
+		if (maxtot <= maxlen->max_l3_len)
+			return maxlen->val;
 	}
 
-	return n;
+	return -1;
 }
 
 static int gmac_init(struct net_device *netdev)
-- 
2.17.1

^ permalink raw reply related	[flat|nested] 10+ messages in thread
end of thread, other threads:[~2018-07-11 19:16 UTC | newest]

Thread overview: 10+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2018-07-04 18:33 [PATCH net-next 1/5 v2] net: gemini: Look up L3 maxlen from table Linus Walleij
2018-07-04 18:33 ` [PATCH net-next 2/5 v2] net: gemini: Improve connection prints Linus Walleij
2018-07-04 20:40   ` Andrew Lunn
2018-07-08 20:47     ` Linus Walleij
2018-07-04 18:33 ` [PATCH net-next 3/5 v2] net: gemini: Allow multiple ports to instantiate Linus Walleij
2018-07-04 18:33 ` [PATCH net-next 4/5 v2] net: gemini: Move main init to port Linus Walleij
2018-07-04 18:33 ` [PATCH net-next 5/5 v2] net: gemini: Indicate that we can handle jumboframes Linus Walleij
2018-07-04 20:35   ` Andrew Lunn
2018-07-11 19:10     ` Linus Walleij
2018-07-07 16:14 ` [PATCH net-next 1/5 v2] net: gemini: Look up L3 maxlen from table Michał Mirosław

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