From: Michael Buesch <mb@bu3sch•de>
To: David Miller <davem@davemloft•net>
Cc: dave@thedillows•org, michael.riepe@googlemail•com,
romieu@fr•zoreil.com, rsantos@grupopie•com, m.bueker@berlin•de,
linux-kernel@vger•kernel.org, netdev@vger•kernel.org
Subject: Re: [PATCH 2.6.30-rc4] r8169: avoid losing MSI interrupts
Date: Wed, 27 May 2009 18:19:00 +0200 [thread overview]
Message-ID: <200905271819.01479.mb@bu3sch.de> (raw)
In-Reply-To: <20090526.151410.109935435.davem@davemloft.net>
On Wednesday 27 May 2009 00:14:10 David Miller wrote:
> From: David Miller <davem@davemloft•net>
> Date: Tue, 26 May 2009 14:52:11 -0700 (PDT)
>
> > From: Michael Buesch <mb@bu3sch•de>
> > Date: Tue, 26 May 2009 20:22:23 +0200
> >
> >> I didn't notice a CC:stable.
> >> I think this should also go to stable.
> >> Does somebody take care?
> >
> > I'll queue it up.
>
> Actually, this patch doesn't even remotely come close to applying
> to 2.6.29.4
Wiggle is able to apply it cleanly.
I already posted a wiggle'd patch.
It's also attached to this mail.
Index: linux-2.6.29/drivers/net/r8169.c
===================================================================
--- linux-2.6.29.orig/drivers/net/r8169.c 2009-05-23 11:06:22.000000000 +0200
+++ linux-2.6.29/drivers/net/r8169.c 2009-05-23 11:08:17.000000000 +0200
@@ -3554,54 +3554,64 @@
int handled = 0;
int status;
+ /* loop handling interrupts until we have no new ones or
+ * we hit a invalid/hotplug case.
+ */
status = RTL_R16(IntrStatus);
+ while (status && status != 0xffff) {
+ handled = 1;
- /* hotplug/major error/no more work/shared irq */
- if ((status == 0xffff) || !status)
- goto out;
-
- handled = 1;
+ /* Handle all of the error cases first. These will reset
+ * the chip, so just exit the loop.
+ */
+ if (unlikely(!netif_running(dev))) {
+ rtl8169_asic_down(ioaddr);
+ break;
+ }
- if (unlikely(!netif_running(dev))) {
- rtl8169_asic_down(ioaddr);
- goto out;
- }
+ /* Work around for rx fifo overflow */
+ if (unlikely(status & RxFIFOOver) &&
+ (tp->mac_version == RTL_GIGA_MAC_VER_11)) {
+ netif_stop_queue(dev);
+ rtl8169_tx_timeout(dev);
+ break;
+ }
- status &= tp->intr_mask;
- RTL_W16(IntrStatus,
- (status & RxFIFOOver) ? (status | RxOverflow) : status);
+ if (unlikely(status & SYSErr)) {
+ rtl8169_pcierr_interrupt(dev);
+ break;
+ }
- if (!(status & tp->intr_event))
- goto out;
+ if (status & LinkChg)
+ rtl8169_check_link_status(dev, tp, ioaddr);
- /* Work around for rx fifo overflow */
- if (unlikely(status & RxFIFOOver) &&
- (tp->mac_version == RTL_GIGA_MAC_VER_11)) {
- netif_stop_queue(dev);
- rtl8169_tx_timeout(dev);
- goto out;
- }
+ /* We need to see the lastest version of tp->intr_mask to
+ * avoid ignoring an MSI interrupt and having to wait for
+ * another event which may never come.
+ */
+ smp_rmb();
+ if (status & tp->intr_mask & tp->napi_event) {
+ RTL_W16(IntrMask, tp->intr_event & ~tp->napi_event);
+ tp->intr_mask = ~tp->napi_event;
+
+ if (likely(netif_rx_schedule_prep(&tp->napi)))
+ __netif_rx_schedule(&tp->napi);
+ else if (netif_msg_intr(tp)) {
+ printk(KERN_INFO "%s: interrupt %04x in poll\n",
+ dev->name, status);
+ }
+ }
- if (unlikely(status & SYSErr)) {
- rtl8169_pcierr_interrupt(dev);
- goto out;
+ /* We only get a new MSI interrupt when all active irq
+ * sources on the chip have been acknowledged. So, ack
+ * everything we've seen and check if new sources have become
+ * active to avoid blocking all interrupts from the chip.
+ */
+ RTL_W16(IntrStatus,
+ (status & RxFIFOOver) ? (status | RxOverflow) : status);
+ status = RTL_R16(IntrStatus);
}
- if (status & LinkChg)
- rtl8169_check_link_status(dev, tp, ioaddr);
-
- if (status & tp->napi_event) {
- RTL_W16(IntrMask, tp->intr_event & ~tp->napi_event);
- tp->intr_mask = ~tp->napi_event;
-
- if (likely(netif_rx_schedule_prep(&tp->napi)))
- __netif_rx_schedule(&tp->napi);
- else if (netif_msg_intr(tp)) {
- printk(KERN_INFO "%s: interrupt %04x in poll\n",
- dev->name, status);
- }
- }
-out:
return IRQ_RETVAL(handled);
}
@@ -3617,13 +3627,15 @@
if (work_done < budget) {
netif_rx_complete(napi);
- tp->intr_mask = 0xffff;
- /*
- * 20040426: the barrier is not strictly required but the
- * behavior of the irq handler could be less predictable
- * without it. Btw, the lack of flush for the posted pci
- * write is safe - FR
+
+ /* We need for force the visibility of tp->intr_mask
+ * for other CPUs, as we can loose an MSI interrupt
+ * and potentially wait for a retransmit timeout if we don't.
+ * The posted write to IntrMask is safe, as it will
+ * eventually make it to the chip and we won't loose anything
+ * until it does.
*/
+ tp->intr_mask = 0xffff;
smp_wmb();
RTL_W16(IntrMask, tp->intr_event);
}
--
Greetings, Michael.
next prev parent reply other threads:[~2009-05-27 16:19 UTC|newest]
Thread overview: 77+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <200903041828.49972.m.bueker@berlin.de>
[not found] ` <20090322211159.GA23042@electric-eye.fr.zoreil.com>
[not found] ` <49CA1822.6050902@grupopie.com>
[not found] ` <200904041950.04324.mb@bu3sch.de>
[not found] ` <4A06D8D2.4010505@googlemail.com>
2009-05-11 0:29 ` 2.6.27.19 + 28.7: network timeouts for r8169 and 8139too David Dillow
2009-05-11 20:48 ` Michael Buesch
2009-05-11 21:10 ` Michael Buesch
2009-05-11 21:29 ` David Dillow
2009-05-11 21:59 ` Michael Buesch
2009-05-12 20:29 ` Michael Riepe
2009-05-14 2:38 ` David Dillow
2009-05-14 18:37 ` Michael Riepe
2009-05-14 19:14 ` David Dillow
2009-05-14 19:42 ` Michael Riepe
2009-05-23 1:29 ` [PATCH 2.6.30-rc4] r8169: avoid losing MSI interrupts David Dillow
2009-05-23 9:24 ` Michael Buesch
2009-05-23 14:35 ` Michael Riepe
2009-05-23 14:44 ` Michael Buesch
2009-05-23 15:01 ` Michael Riepe
2009-05-23 16:40 ` Michael Buesch
2009-05-23 14:51 ` David Dillow
2009-05-23 16:12 ` Michael Riepe
2009-05-23 16:45 ` Michael Buesch
2009-05-23 16:46 ` David Dillow
2009-05-23 16:50 ` Michael Buesch
2009-05-23 16:53 ` Michael Riepe
2009-05-23 17:03 ` David Dillow
2009-05-24 21:15 ` Francois Romieu
2009-05-24 22:55 ` David Dillow
2009-05-26 5:55 ` David Miller
2009-05-26 18:22 ` Michael Buesch
2009-05-26 21:52 ` David Miller
2009-05-26 22:14 ` David Miller
2009-05-26 22:40 ` Michael Riepe
2009-05-26 22:43 ` David Miller
2009-05-26 23:10 ` David Miller
2009-05-27 16:19 ` Michael Buesch [this message]
2009-06-16 19:32 ` Rui Santos
2009-08-21 20:57 ` Eric W. Biederman
2009-08-21 21:22 ` Michael Riepe
2009-08-21 22:59 ` David Dillow
2009-08-21 23:34 ` David Dillow
2009-08-22 0:24 ` Eric W. Biederman
2009-08-22 11:48 ` Eric W. Biederman
2009-08-22 12:07 ` Eric W. Biederman
2009-08-22 20:43 ` David Dillow
2009-08-23 17:17 ` Jarek Poplawski
2009-08-23 17:43 ` Michal Soltys
2009-08-23 17:54 ` Jarek Poplawski
2009-08-24 2:37 ` Eric W. Biederman
2009-08-25 0:51 ` Eric W. Biederman
2009-08-25 2:59 ` David Dillow
2009-08-25 20:22 ` Eric W. Biederman
2009-08-25 20:40 ` David Dillow
2009-08-25 21:24 ` Eric W. Biederman
2009-08-25 21:46 ` David Dillow
2009-08-25 22:19 ` Francois Romieu
2009-08-26 3:47 ` Eric W. Biederman
2009-08-26 7:58 ` [PATCH] r8169: Reduce looping in the interrupt handler Eric W. Biederman
2009-08-26 13:56 ` David Dillow
2009-08-26 13:59 ` David Dillow
2009-08-26 20:02 ` Eric W. Biederman
2009-08-26 21:30 ` Francois Romieu
2009-08-26 21:40 ` Eric W. Biederman
2009-08-27 5:24 ` Francois Romieu
2009-08-27 5:38 ` Eric W. Biederman
2009-08-27 23:20 ` Francois Romieu
2009-08-28 1:17 ` Eric W. Biederman
2009-08-28 1:29 ` David Dillow
2009-08-30 20:37 ` Francois Romieu
2009-08-30 20:53 ` Eric W. Biederman
2009-09-01 3:33 ` David Dillow
2009-09-01 9:20 ` Francois Romieu
2009-08-25 21:37 ` [PATCH 2.6.30-rc4] r8169: avoid losing MSI interrupts Eric W. Biederman
2009-08-25 21:54 ` David Dillow
2009-08-25 23:11 ` Francois Romieu
2009-05-12 11:10 ` 2.6.27.19 + 28.7: network timeouts for r8169 and 8139too Krzysztof Halasa
2009-05-12 21:45 ` Michael Riepe
2009-05-13 6:11 ` Francois Romieu
2009-05-13 6:27 ` Michael Riepe
2009-05-13 19:34 ` Krzysztof Halasa
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=200905271819.01479.mb@bu3sch.de \
--to=mb@bu3sch$(echo .)de \
--cc=dave@thedillows$(echo .)org \
--cc=davem@davemloft$(echo .)net \
--cc=linux-kernel@vger$(echo .)kernel.org \
--cc=m.bueker@berlin$(echo .)de \
--cc=michael.riepe@googlemail$(echo .)com \
--cc=netdev@vger$(echo .)kernel.org \
--cc=romieu@fr$(echo .)zoreil.com \
--cc=rsantos@grupopie$(echo .)com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
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