Re: [Bugfix] PCI, x86: Correctly allocate IRQs for PCI devices managed by non-PCI drivers
From: Arthur Marsh
Date: Tue Sep 08 2015 - 05:03:36 EST
Jiang Liu wrote on 08/09/15 16:56:
Commit 991de2e59090 ("PCI, x86: Implement pcibios_alloc_irq() and
pcibios_free_irq()") changes the way to allocate PCI legacy IRQ
for PCI devices on x86 platforms. Instead of allocating PCI legacy
IRQs when pcibios_enable_device() gets called, now pcibios_alloc_irq()
will be called by pci_device_probe() to allocate PCI legacy IRQs
when binding PCI drivers to PCI devices.
But some device drivers, such as eata, directly access PCI devices
without implementing corresponding PCI drivers, so pcibios_alloc_irq()
won't be called for those PCI devices and wrong IRQ number may be
used to manage the PCI device.
So detect such a case in pcibios_enable_device() by checking
pci_dev->driver is NULL and call pcibios_alloc_irq() to allocate PCI
legacy IRQs.
Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxxxxxxx>
---
arch/x86/pci/common.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/arch/x86/pci/common.c b/arch/x86/pci/common.c
index 09d3afc0a181..60b237783582 100644
--- a/arch/x86/pci/common.c
+++ b/arch/x86/pci/common.c
@@ -685,6 +685,16 @@ void pcibios_free_irq(struct pci_dev *dev)
int pcibios_enable_device(struct pci_dev *dev, int mask)
{
+ /*
+ * By design, pcibios_alloc_irq() will be called by pci_device_probe()
+ * when binding a PCI device to a PCI driver. But some device drivers,
+ * such as eata, directly make use of PCI devices without implementing
+ * PCI device drivers, so pcibios_alloc_irq() won't be called for those
+ * PCI devices.
+ */
+ if (!dev->driver)
+ pcibios_alloc_irq(dev);
+
return pci_enable_resources(dev, mask);
}
Thanks, I removed the test patch and applied the revised patch and built
and rebooted the kernel and successfully mounted file systems on a disk
attached to the DPT 2044W card using the eata driver:
[ 0.000000] Linux version 4.2.0+ (root@victoria) (gcc version 5.2.1
20150903
(Debian 5.2.1-16) ) #31 SMP PREEMPT Tue Sep 8 17:36:28 ACST 2015
...
[ 80.691097] EATA0: IRQ 10 mapped to IO-APIC IRQ 17.
[ 80.724519] EATA/DMA 2.0x: Copyright (C) 1994-2003 Dario Ballabio.
[ 80.752035] EATA config options -> tm:1, lc:y, mq:16, rs:y, et:n,
ip:n, ep:n, pp:y.
[ 80.777063] EATA0: 2.0C, PCI 0xd890, IRQ 17, BMST, SG 122, MB 64.
[ 80.802391] EATA0: wide SCSI support enabled, max_id 16, max_lun 8.
[ 80.827959] EATA0: SCSI channel 0 enabled, host target ID 7.
[ 80.853413] scsi host3: EATA/DMA 2.0x rev. 8.10.00
[ 82.445662] scsi 3:0:6:0: Direct-Access IBM DCAS-34330W
S65A PQ: 0 ANSI: 2
[ 82.471584] scsi 3:0:6:0: cmds/lun 16, sorted, simple tags.
[ 84.571451] sd 3:0:6:0: Attached scsi generic sg4 type 0
[ 84.597572] sd 3:0:6:0: [sdd] 8466688 512-byte logical blocks: (4.33
GB/4.03 GiB)
[ 84.659874] sd 3:0:6:0: [sdd] Write Protect is off
[ 84.688543] sd 3:0:6:0: [sdd] Mode Sense: b3 00 00 08
[ 84.714021] sd 3:0:6:0: [sdd] Write cache: enabled, read cache:
enabled, doesn't support DPO or FUA
[ 84.817682] sdd: sdd1 sdd2 < sdd5 >
[ 84.919267] sd 3:0:6:0: [sdd] Attached SCSI disk
Arthur.
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