From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: [PATCH 3/3] sky2: beter ram buffer partitioning Date: Mon, 4 Dec 2006 15:53:45 -0800 Message-ID: <20061204155345.0c276a90@freekitty> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org Return-path: Received: from smtp.osdl.org ([65.172.181.25]:36486 "EHLO smtp.osdl.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S937152AbWLDXxw (ORCPT ); Mon, 4 Dec 2006 18:53:52 -0500 To: Jeff Garzik Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Different chips have different sizes of ram buffers, and some versions have no ram buffer at all!. Be more careful about sizing the ram usage because it maybe a problem if vendor keeps changing sizes. There is the (unlikely) possibility that some of the errors on some of the chips have been caused by partitioning not on a 1K boundary. Signed-off-by: Stephen Hemminger --- drivers/net/sky2.c | 41 +++++++++++++++++++++++++---------------- 1 file changed, 25 insertions(+), 16 deletions(-) --- sky2.orig/drivers/net/sky2.c 2006-12-04 12:47:19.000000000 -0800 +++ sky2/drivers/net/sky2.c 2006-12-04 13:19:49.000000000 -0800 @@ -696,10 +696,15 @@ } -/* Assign Ram Buffer allocation in units of 64bit (8 bytes) */ -static void sky2_ramset(struct sky2_hw *hw, u16 q, u32 start, u32 end) +/* Assign Ram Buffer allocation to queue */ +static void sky2_ramset(struct sky2_hw *hw, u16 q, u32 start, u32 space) { - pr_debug(PFX "q %d %#x %#x\n", q, start, end); + u32 end; + + /* convert from K bytes to qwords used for hw register */ + start *= 1024/8; + space *= 1024/8; + end = start + space - 1; sky2_write8(hw, RB_ADDR(q, RB_CTRL), RB_RST_CLR); sky2_write32(hw, RB_ADDR(q, RB_START), start); @@ -708,7 +713,6 @@ sky2_write32(hw, RB_ADDR(q, RB_RP), start); if (q == Q_R1 || q == Q_R2) { - u32 space = end - start + 1; u32 tp = space - space/4; /* On receive queue's set the thresholds @@ -1138,7 +1142,7 @@ struct sky2_port *sky2 = netdev_priv(dev); struct sky2_hw *hw = sky2->hw; unsigned port = sky2->port; - u32 ramsize, rxspace, imask; + u32 ramsize, imask; int cap, err = -ENOMEM; struct net_device *otherdev = hw->dev[sky2->port^1]; @@ -1191,20 +1195,25 @@ sky2_mac_init(hw, port); - /* Determine available ram buffer space in qwords. */ - ramsize = sky2_read8(hw, B2_E_0) * 4096/8; + /* Register is number of 4K blocks on internal RAM buffer. */ + ramsize = sky2_read8(hw, B2_E_0) * 4; + printk(KERN_INFO PFX "%s: ram buffer %dK\n", dev->name, ramsize); - if (ramsize > 6*1024/8) - rxspace = ramsize - (ramsize + 2) / 3; - else - rxspace = ramsize / 2; + if (ramsize > 0) { + u32 rxspace; - sky2_ramset(hw, rxqaddr[port], 0, rxspace-1); - sky2_ramset(hw, txqaddr[port], rxspace, ramsize-1); + if (ramsize < 16) + rxspace = ramsize / 2; + else + rxspace = 8 + (2*(ramsize - 16))/3; - /* Make sure SyncQ is disabled */ - sky2_write8(hw, RB_ADDR(port == 0 ? Q_XS1 : Q_XS2, RB_CTRL), - RB_RST_SET); + sky2_ramset(hw, rxqaddr[port], 0, rxspace); + sky2_ramset(hw, txqaddr[port], rxspace, ramsize - rxspace); + + /* Make sure SyncQ is disabled */ + sky2_write8(hw, RB_ADDR(port == 0 ? Q_XS1 : Q_XS2, RB_CTRL), + RB_RST_SET); + } sky2_qset(hw, txqaddr[port]); -- Stephen Hemminger