linux-arm-kernel.lists.infradead.org archive mirror
 help / color / mirror / Atom feed
* [PATCH net-next 1/5] net: gemini: Look up L3 maxlen from table
@ 2018-06-30 16:18 Linus Walleij
  2018-06-30 16:18 ` [PATCH net-next 2/5] net: gemini: Improve connection prints Linus Walleij
                   ` (3 more replies)
  0 siblings, 4 replies; 7+ messages in thread
From: Linus Walleij @ 2018-06-30 16:18 UTC (permalink / raw)
  To: linux-arm-kernel

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>
---
 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] 7+ messages in thread

end of thread, other threads:[~2018-07-01  7:58 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2018-06-30 16:18 [PATCH net-next 1/5] net: gemini: Look up L3 maxlen from table Linus Walleij
2018-06-30 16:18 ` [PATCH net-next 2/5] net: gemini: Improve connection prints Linus Walleij
2018-07-01  7:54   ` Andrew Lunn
2018-06-30 16:18 ` [PATCH net-next 3/5] net: gemini: Allow multiple ports to instantiate Linus Walleij
2018-06-30 16:18 ` [PATCH net-next 4/5] net: gemini: Move main init to port Linus Walleij
2018-06-30 16:18 ` [PATCH net-next 5/5] net: gemini: Indicate that we can handle jumboframes Linus Walleij
2018-07-01  7:58   ` Andrew Lunn

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).