On Fri, Jan 05, 2018 at 01:49:58PM -0500, Mikulas Patocka wrote:
>
>
> On Fri, 5 Jan 2018, Lorenzo Pieralisi wrote:
>
> > On Tue, Jan 02, 2018 at 04:32:45PM -0500, Mikulas Patocka wrote:
> > > Hi
> > >
> > > The patch 0e4c2eeb758a91e68b9eaf7a4bee9bd5ed97ff2b ("alpha/PCI: Replace
> > > pci_fixup_irqs() call with host bridge IRQ mapping hooks") breaks
> > > networking on Alpha for me. I have an Alpha Avanti server with tulip
> > > network card.
> > >
> > > The patch 0e4c2eeb breaks it so that I get MCE when the network card
> > > driver is loaded. The patch 814eae59 fixes the MCE, the system boot
> > > completes, but the network card doesn't receive any interrupts (and soon
> > > it reports warning about timeout on tx queue). All kernels in the 4.14
> > > branch have this bug.
> >
> > I reworked the patch, please let me know if it does fix the issue.
> >
> > Thanks,
> > Lorenzo
>
> Networking doesn't work, other interrupts work.
>
> With this patch, /proc/interrupts shows one interrupt for the network card
> (it used to be zero without this patch).
It is getting harder to understand what's going on, here's an
incremental patch with some logging, it would be ideal to add
a similar logging with a working kernel so that we can actually
compare the IRQ level registers programming, please test it
when you have time.
Patch here:
-- >8 --
diff --git a/arch/alpha/kernel/sys_sio.c b/arch/alpha/kernel/sys_sio.c
index 37bd6d9b8eb9..086f53a89dfc 100644
--- a/arch/alpha/kernel/sys_sio.c
+++ b/arch/alpha/kernel/sys_sio.c
@@ -102,6 +102,15 @@ sio_pci_route(void)
alpha_mv.sys.sio.route_tab);
}
+static bool sio_pci_dev_irq_needs_level(const struct pci_dev *dev)
+{
+ if ((dev->class >> 16 == PCI_BASE_CLASS_BRIDGE) &&
+ (dev->class >> 8 != PCI_CLASS_BRIDGE_PCMCIA))
+ return false;
+
+ return true;
+}
+
static unsigned int __init
sio_collect_irq_levels(void)
{
@@ -110,8 +119,7 @@ sio_collect_irq_levels(void)
/* Iterate through the devices, collecting IRQ levels. */
for_each_pci_dev(dev) {
- if ((dev->class >> 16 == PCI_BASE_CLASS_BRIDGE) &&
- (dev->class >> 8 != PCI_CLASS_BRIDGE_PCMCIA))
+ if (!sio_pci_dev_irq_needs_level(dev))
continue;
if (dev->irq)
@@ -120,8 +128,7 @@ sio_collect_irq_levels(void)
return level_bits;
}
-static void __init
-sio_fixup_irq_levels(unsigned int level_bits)
+static void __sio_fixup_irq_levels(unsigned int level_bits, bool reset)
{
unsigned int old_level_bits;
@@ -139,10 +146,21 @@ sio_fixup_irq_levels(unsigned int level_bits)
*/
old_level_bits = inb(0x4d0) | (inb(0x4d1) << 8);
- level_bits |= (old_level_bits & 0x71ff);
+ if (reset)
+ old_level_bits &= 0x71ff;
+
+ level_bits |= old_level_bits;
outb((level_bits >> 0) & 0xff, 0x4d0);
outb((level_bits >> 8) & 0xff, 0x4d1);
+
+ pr_info("%s: level bits %ux\n", __func__, level_bits);
+}
+
+static inline void
+sio_fixup_irq_levels(unsigned int level_bits)
+{
+ __sio_fixup_irq_levels(level_bits, true);
}
static inline int
@@ -181,6 +199,11 @@ noname_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
const long min_idsel = 6, max_idsel = 14, irqs_per_slot = 5;
int irq = COMMON_TABLE_LOOKUP, tmp;
tmp = __kernel_extbl(alpha_mv.sys.sio.route_tab, irq);
+
+ /* Fixup IRQ level if an actual IRQ mapping is detected */
+ if (sio_pci_dev_irq_needs_level(dev) && (irq >= 0 && tmp))
+ __sio_fixup_irq_levels(1 << tmp, false);
+
return irq >= 0 ? tmp : -1;
}
--
2.15.0
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