From: Brice Goglin <brice@myri.com>
To: Jeff Garzik <jeff@garzik.org>
Cc: netdev@vger.kernel.org
Subject: [PATCH 2.6.28] myri10ge: fix stop/go ordering even more
Date: Mon, 10 Nov 2008 13:58:41 +0100 [thread overview]
Message-ID: <49183001.5010405@myri.com> (raw)
The doorbell writes may be seen out of order by the firmware if they
are in WC memory since the tx spin(un)lock does not flush WC writes.
Hence if the "stop" is written on a different CPU than the "go", it
is possible that the stop will arrive after the go unless we add an
explicit memory barrier (and mmiowb() is not enough).
It fixes transmit hangs in multi tx queue mode.
Signed-off-by: Brice Goglin <brice@myri.com>
--- linux-git/drivers/net/myri10ge/myri10ge.c 2008-11-07 10:01:32.000000000 +0100
+++ linux-tmp/drivers/net/myri10ge/myri10ge.c 2008-11-07 13:58:07.000000000 +0100
@@ -75,7 +75,7 @@
#include "myri10ge_mcp.h"
#include "myri10ge_mcp_gen_header.h"
-#define MYRI10GE_VERSION_STR "1.4.3-1.375"
+#define MYRI10GE_VERSION_STR "1.4.3-1.378"
MODULE_DESCRIPTION("Myricom 10G driver (10GbE)");
MODULE_AUTHOR("Maintainer: help@myri.com");
@@ -1393,6 +1393,7 @@
if (tx->req == tx->done) {
tx->queue_active = 0;
put_be32(htonl(1), tx->send_stop);
+ mb();
mmiowb();
}
__netif_tx_unlock(dev_queue);
@@ -2865,6 +2866,7 @@
if ((mgp->dev->real_num_tx_queues > 1) && tx->queue_active == 0) {
tx->queue_active = 1;
put_be32(htonl(1), tx->send_go);
+ mb();
mmiowb();
}
tx->pkt_start++;
reply other threads:[~2008-11-10 13:00 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
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=49183001.5010405@myri.com \
--to=brice@myri.com \
--cc=jeff@garzik.org \
--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).