netdev.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Stephen Hemminger <shemminger@osdl.org>
To: Jeff Garzik <jgarzik@pobox.com>
Cc: netdev@vger.kernel.org
Subject: [PATCH] sky2: 88E803X transmit lockup
Date: Fri, 20 Oct 2006 17:06:11 -0700	[thread overview]
Message-ID: <20061020170611.1766ae82@freekitty> (raw)

The reason sky2 driver was locking up on transmit on the Yukon-FE chipset
is that it was misconfiguring the internal RAM buffer so the transmitter
and receiver were sharing the same space. 

The code assumed there was 16K of RAM on Yukon-FE (taken from vendor driver
sk98lin which is even more f*cked up on this). Then it assigned based on that.
The giveaway was that the registers would only hold 9bits so both RX/TX
had 0..1ff for space. It is a wonder it worked at all!

This patch addresses this, and fixes an easily reproducible hang on Transmit.
Only the Yukon-FE chip is Marvell 88E803X (10/100 only) are affected.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>

--- sky2.orig/drivers/net/sky2.c	2006-10-20 16:37:56.000000000 -0700
+++ sky2/drivers/net/sky2.c	2006-10-20 16:38:16.000000000 -0700
@@ -699,16 +699,10 @@
 
 }
 
-/* Assign Ram Buffer allocation.
- * start and end are in units of 4k bytes
- * ram registers are in units of 64bit words
- */
-static void sky2_ramset(struct sky2_hw *hw, u16 q, u8 startk, u8 endk)
+/* Assign Ram Buffer allocation in units of 64bit (8 bytes) */
+static void sky2_ramset(struct sky2_hw *hw, u16 q, u32 start, u32 end)
 {
-	u32 start, end;
-
-	start = startk * 4096/8;
-	end = (endk * 4096/8) - 1;
+	pr_debug(PFX "q %d %#x %#x\n", q, start, end);
 
 	sky2_write8(hw, RB_ADDR(q, RB_CTRL), RB_RST_CLR);
 	sky2_write32(hw, RB_ADDR(q, RB_START), start);
@@ -717,7 +711,7 @@
 	sky2_write32(hw, RB_ADDR(q, RB_RP), start);
 
 	if (q == Q_R1 || q == Q_R2) {
-		u32 space = (endk - startk) * 4096/8;
+		u32 space = end - start + 1;
 		u32 tp = space - space/4;
 
 		/* On receive queue's set the thresholds
@@ -1199,19 +1193,16 @@
 
 	sky2_mac_init(hw, port);
 
-	/* Determine available ram buffer space (in 4K blocks).
-	 * Note: not sure about the FE setting below yet
-	 */
-	if (hw->chip_id == CHIP_ID_YUKON_FE)
-		ramsize = 4;
-	else
-		ramsize = sky2_read8(hw, B2_E_0);
+	/* Determine available ram buffer space in qwords.  */
+	ramsize = sky2_read8(hw, B2_E_0) * 4096/8;
 
-	/* Give transmitter one third (rounded up) */
-	rxspace = ramsize - (ramsize + 2) / 3;
+	if (ramsize > 6*1024/8)
+		rxspace = ramsize - (ramsize + 2) / 3;
+	else
+		rxspace = ramsize / 2;
 
-	sky2_ramset(hw, rxqaddr[port], 0, rxspace);
-	sky2_ramset(hw, txqaddr[port], rxspace, ramsize);
+	sky2_ramset(hw, rxqaddr[port], 0, rxspace-1);
+	sky2_ramset(hw, txqaddr[port], rxspace, ramsize-1);
 
 	/* Make sure SyncQ is disabled */
 	sky2_write8(hw, RB_ADDR(port == 0 ? Q_XS1 : Q_XS2, RB_CTRL),

             reply	other threads:[~2006-10-21  0:06 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-10-21  0:06 Stephen Hemminger [this message]
  -- strict thread matches above, loose matches on Subject: below --
2006-10-23 19:20 [PATCH] sky2: 88E803X transmit lockup Daniel J Blueman

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20061020170611.1766ae82@freekitty \
    --to=shemminger@osdl.org \
    --cc=jgarzik@pobox.com \
    --cc=netdev@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
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).