Drop unhandled irq polling patch

2 files changed, 4 insertions, 250 deletions

diff --git a/kernel.spec b/kernel.spec
index 875e93181..93fbbbc79 100644
--- a/kernel.spec
+++ b/kernel.spec
@@ -62,7 +62,7 @@ Summary: The Linux kernel
 # For non-released -rc kernels, this will be appended after the rcX and
 # gitX tags, so a 3 here would become part of release "0.rcX.gitX.3"
 #
-%global baserelease 1
+%global baserelease 2
 %global fedora_build %{baserelease}
 
 # base_sublevel is the kernel version we're starting with and patching
@@ -741,8 +741,6 @@ Patch21094: power-x86-destdir.patch
 #rhbz 754518
 Patch21235: scsi-sd_revalidate_disk-prevent-NULL-ptr-deref.patch
 
-Patch21400: unhandled-irqs-switch-to-polling.patch
-
 Patch22000: weird-root-dentry-name-debug.patch
 
 #selinux ptrace child permissions
@@ -1445,8 +1443,6 @@ ApplyPatch power-x86-destdir.patch
 #rhbz 754518
 ApplyPatch scsi-sd_revalidate_disk-prevent-NULL-ptr-deref.patch
 
-ApplyPatch unhandled-irqs-switch-to-polling.patch
-
 ApplyPatch weird-root-dentry-name-debug.patch
 
 #selinux ptrace child permissions
@@ -2311,6 +2307,9 @@ fi
 #                 ||----w |
 #                 ||     ||
 %changelog
+* Tue Oct 09 2012 Josh Boyer <jwboyer@redhat.com>
+- Drop unhandled irq polling patch
+
 * Mon Oct 08 2012 Justin M. Forbes <jforbes@redhat.com>
 - v3.6-8559-ge9eca4d
 
diff --git a/unhandled-irqs-switch-to-polling.patch b/unhandled-irqs-switch-to-polling.patch
deleted file mode 100644
index 0fc4d080e..000000000
--- a/unhandled-irqs-switch-to-polling.patch
+++ /dev/null
@@ -1,245 +0,0 @@
-From f9b32cd97783f2be14386f1347439e86109050b9 Mon Sep 17 00:00:00 2001
-From: Jeroen Van den Keybus <jeroen.vandenkeybus@gmail.com>
-Date: Mon, 30 Jan 2012 22:37:28 +0100
-Subject: [PATCH] Unhandled IRQs on AMD E-450: temporarily switch to
- low-performance polling IRQ mode
-
-It seems that some motherboard designs using the ASM1083 PCI/PCIe
-bridge (PCI device ID 1b21:1080, Rev. 01) suffer from stuck IRQ lines
-on the PCI bus (causing the kernel to emit 'IRQxx: nobody cared' and
-disable the IRQ). The following patch is an attempt to mitigate the
-serious impact of permanently disabling an IRQ in that case and
-actually make PCI devices better usable on this platform.
-
-It seems that the bridge fails to issue a IRQ deassertion message on
-the PCIe bus, when the relevant driver causes the interrupting PCI
-device to deassert its IRQ line. To solve this issue, it was tried to
-re-issue an IRQ on a PCI device being able to do so (e1000 in this
-case), but we suspect that the attempt to re-assert/deassert may have
-occurred too soon after the initial IRQ for the ASM1083. Anyway, it
-didn't work but if, after some delay, a new IRQ occurred, the related
-IRQ deassertion message eventually did clear the IOAPIC IRQ. It would
-be useful to re-enable the IRQ here.
-
-Therefore the patch below to poll_spurious_irqs() in spurious.c is
-proposed, It does the following:
-
-1. lets the kernel decide that an IRQ is unhandled after only 10
-positives (instead of 100,000);
-2. briefly (a few seconds or so, currently 1 s) switches to polling
-IRQ at a higher rate than usual (100..1,000Hz instead of 10Hz,
-currently 100Hz), but not too high to avoid excessive CPU load. Any
-device drivers 'see' their interrupts handled with a higher latency
-than usual, but they will still operate properly;
-3. afterwards, simply reenable the IRQ.
-
-If proper operation of the PCIe legacy IRQ line emulation is restored
-after 3, the system operates again at normal performance. If the IRQ
-is still stuck after this procedure, the sequence repeats.
-
-If a genuinely stuck IRQ is used with this solution, the system would
-simply sustain short bursts of 10 unhandled IRQs per second, and use
-polling mode indefinitely at a moderate 100Hz rate. It seemed a good
-alternative to the default irqpoll behaviour to me, which is why I
-left it in poll_spurious_irqs() (instead of creating a new kernel
-option). Additionally, if any device happens to share an IRQ with a
-faulty one, that device is no longer banned forever.
-
-Debugging output is still present and may be removed. Bad IRQ
-reporting is also commented out now.
-
-I have now tried it for about 2 months and I can conclude the following:
-
-1. The patch works and, judging from my Firewire card interrupt on
-IRQ16, which repeats every 64 secs, I can confirm that the IRQ usually
-gets reset when a new IRQ arrives (polling mode runs for 64 seconds
-every time).
-2. When testing a SiL-3114 SATA PCI card behind the ASM1083, I could
-keep this running at fairly high speeds (50..70MB/s) for an hour or
-so, but eventually the SiL driver crashed. In such conditions the PCI
-system had to deal with a few hundred IRQs per second / polling mode
-kicking in every 5..10 seconds).
-
-I would like to thank Clemens Ladisch for his invaluable help in
-finding a solution (and providing a patch to avoid my SATA going down
-every time during debugging).
-
-Signed-off-by: Jeroen Van den Keybus <jeroen.vandenkeybus@gmail.com>
-
-Make it less chatty.  Only kick it in if we detect an ASM1083 PCI bridge.
-Fix logic error due to lack of braces
-
-Josh Boyer <jwboyer@redhat.com>
-======
----
- drivers/pci/quirks.c  |   16 +++++++++++
- kernel/irq/spurious.c |   73 +++++++++++++++++++++++++++++++++++++++---------
- 2 files changed, 75 insertions(+), 14 deletions(-)
-
-diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
-index 78fda9c..6ba5dbf 100644
---- a/drivers/pci/quirks.c
-+++ b/drivers/pci/quirks.c
-@@ -1677,6 +1677,22 @@ DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL,	0x2609, quirk_intel_pcie_pm);
- DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL,	0x260a, quirk_intel_pcie_pm);
- DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL,	0x260b, quirk_intel_pcie_pm);
- 
-+/* ASM108x transparent PCI bridges apparently have broken IRQ deassert
-+ * handling.  This causes interrupts to get "stuck" and eventually disabled.
-+ * However, the interrupts are often shared and disabling them is fairly bad.
-+ * It's been somewhat successful to switch to polling mode and retry after
-+ * a bit, so let's do that.
-+ */
-+extern int irq_poll_and_retry;
-+static void quirk_asm108x_poll_interrupts(struct pci_dev *dev)
-+{
-+	dev_info(&dev->dev, "Buggy bridge found [%04x:%04x]\n",
-+		dev->vendor, dev->device);
-+	dev_info(&dev->dev, "Stuck interrupts will be polled and retried\n");
-+	irq_poll_and_retry = 1;
-+}
-+DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_ASMEDIA,	0x1080,	quirk_asm108x_poll_interrupts);
-+
- #ifdef CONFIG_X86_IO_APIC
- /*
-  * Boot interrupts on some chipsets cannot be turned off. For these chipsets,
-diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c
-index 611cd60..f722eb6 100644
---- a/kernel/irq/spurious.c
-+++ b/kernel/irq/spurious.c
-@@ -18,6 +18,8 @@
- 
- static int irqfixup __read_mostly;
- 
-+int irq_poll_and_retry = 0;
-+
- #define POLL_SPURIOUS_IRQ_INTERVAL (HZ/10)
- static void poll_spurious_irqs(unsigned long dummy);
- static DEFINE_TIMER(poll_spurious_irq_timer, poll_spurious_irqs, 0, 0);
-@@ -141,12 +143,13 @@ out:
- static void poll_spurious_irqs(unsigned long dummy)
- {
- 	struct irq_desc *desc;
--	int i;
-+	int i, poll_again;
- 
- 	if (atomic_inc_return(&irq_poll_active) != 1)
- 		goto out;
- 	irq_poll_cpu = smp_processor_id();
- 
-+	poll_again = 0; /* Will stay false as long as no polling candidate is found */
- 	for_each_irq_desc(i, desc) {
- 		unsigned int state;
- 
-@@ -159,14 +162,33 @@ static void poll_spurious_irqs(unsigned long dummy)
- 		if (!(state & IRQS_SPURIOUS_DISABLED))
- 			continue;
- 
--		local_irq_disable();
--		try_one_irq(i, desc, true);
--		local_irq_enable();
-+		/* We end up here with a disabled spurious interrupt.
-+		   desc->irqs_unhandled now tracks the number of times
-+		   the interrupt has been polled */
-+		if (irq_poll_and_retry) {
-+			if (desc->irqs_unhandled < 100) { /* 1 second delay with poll frequency 100 Hz */
-+				local_irq_disable();
-+				try_one_irq(i, desc, true);
-+				local_irq_enable();
-+				desc->irqs_unhandled++;
-+				poll_again = 1;
-+			} else {
-+				irq_enable(desc); /* Reenable the interrupt line */
-+				desc->depth--;
-+				desc->istate &= (~IRQS_SPURIOUS_DISABLED);
-+				desc->irqs_unhandled = 0;
-+			}
-+		} else {
-+			local_irq_disable();
-+			try_one_irq(i, desc, true);
-+			local_irq_enable();
-+		}
- 	}
-+	if (poll_again)
-+		mod_timer(&poll_spurious_irq_timer,
-+			  jiffies + POLL_SPURIOUS_IRQ_INTERVAL);
- out:
- 	atomic_dec(&irq_poll_active);
--	mod_timer(&poll_spurious_irq_timer,
--		  jiffies + POLL_SPURIOUS_IRQ_INTERVAL);
- }
- 
- static inline int bad_action_ret(irqreturn_t action_ret)
-@@ -177,11 +199,19 @@ static inline int bad_action_ret(irqreturn_t action_ret)
- }
- 
- /*
-- * If 99,900 of the previous 100,000 interrupts have not been handled
-+ * If 9 of the previous 10 interrupts have not been handled
-  * then assume that the IRQ is stuck in some manner. Drop a diagnostic
-  * and try to turn the IRQ off.
-  *
-- * (The other 100-of-100,000 interrupts may have been a correctly
-+ * Although this may cause early deactivation of a sporadically
-+ * malfunctioning IRQ line, the poll system will:
-+ * a) Poll it for 100 cycles at a 100 Hz rate
-+ * b) Reenable it afterwards
-+ *
-+ * In worst case, with current settings,  this will cause short bursts
-+ * of 10 interrupts every second.
-+ *
-+ * (The other single interrupt may have been a correctly
-  *  functioning device sharing an IRQ with the failing one)
-  */
- static void
-@@ -269,6 +299,8 @@ try_misrouted_irq(unsigned int irq, struct irq_desc *desc,
- void note_interrupt(unsigned int irq, struct irq_desc *desc,
- 		    irqreturn_t action_ret)
- {
-+	int unhandled_thresh = 999000;
-+
- 	if (desc->istate & IRQS_POLL_INPROGRESS)
- 		return;
- 
-@@ -302,19 +334,32 @@ void note_interrupt(unsigned int irq, struct irq_desc *desc,
- 	}
- 
- 	desc->irq_count++;
--	if (likely(desc->irq_count < 100000))
--		return;
-+	if (!irq_poll_and_retry) {
-+		if (likely(desc->irq_count < 100000))
-+			return;
-+	} else {
-+		if (likely(desc->irq_count < 10))
-+			return;
-+	}
- 
- 	desc->irq_count = 0;
--	if (unlikely(desc->irqs_unhandled > 99900)) {
-+	if (irq_poll_and_retry)
-+		unhandled_thresh = 9;
-+
-+	if (unlikely(desc->irqs_unhandled >= unhandled_thresh)) {
- 		/*
--		 * The interrupt is stuck
-+		 * The interrupt might be stuck
- 		 */
--		__report_bad_irq(irq, desc, action_ret);
-+		if (!irq_poll_and_retry) {
-+			__report_bad_irq(irq, desc, action_ret);
-+			printk(KERN_EMERG "Disabling IRQ %d\n", irq);
-+		} else {
-+			printk(KERN_INFO "IRQ %d might be stuck.  Polling\n",
-+				irq);
-+		}
- 		/*
- 		 * Now kill the IRQ
- 		 */
--		printk(KERN_EMERG "Disabling IRQ #%d\n", irq);
- 		desc->istate |= IRQS_SPURIOUS_DISABLED;
- 		desc->depth++;
- 		irq_disable(desc);
--- 
-1.7.7.6
-