[PATCH v2] drivers/ide/pci: Fix legacy IRQ assignment

From: Lorenzo Pieralisi
Date: Mon Oct 02 2017 - 06:50:19 EST

Through struct pci_host_bridge->{map/swizzle}_irq() hooks is now
possible to define IRQ mapping functions on a per PCI host bridge basis.

Actual IRQ allocation is carried out by the pci_assign_irq() function in
pci_device_probe() - to make sure a device is assigned an IRQ only if it
is probed (ie match a driver); it retrieves a struct pci_host_bridge*
for a given PCI device and through {map/swizzle}_irq() it carries out
the PCI IRQ allocation.

The code conversion to struct pci_host_bridge {map/swizzle}_irq() hooks
and pci_assign_irq() to deal with legacy IRQs in

commit 30fdfb929e82 ("PCI: Add a call to pci_assign_irq() in

did not take into account that the IDE subsystem relies on a special
purpose IDE PCI layer, configured by CONFIG_IDEPCI_PCIBUS_ORDER to force
devices probe ordering by sidestepping the core PCI bus layer entirely
(and therefore pci_device_probe()) by executing the registered IDE PCI
drivers probe routines (ie registered with ide_pci_register_driver())
through ide_scan_pcidev().

Since this IDE PCI specific probe mechanism bypasses the PCI core
code generic probing (ie pci_device_probe()) it also misses the
pci_assign_irq() call (among other PCI initialization functions);
this triggers IDE PCI devices initialization failures caused
by the missing IRQ allocation:

ide0: disabled, no IRQ
ide0: failed to initialize IDE interface
ide0: disabling port
cmd64x 0000:00:02.0: IDE controller (0x1095:0x0646 rev 0x07)
CMD64x_IDE 0000:00:02.0: BAR 0: can't reserve [io 0x8050-0x8057]
cmd64x 0000:00:02.0: can't reserve resources
CMD64x_IDE: probe of 0000:00:02.0 failed with error -16
ide_generic: please use "probe_mask=0x3f" module parameter for probing
all legacy ISA IDE ports
------------[ cut here ]------------
WARNING: CPU: 0 PID: 1 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x94/0xd0
sysfs: cannot create duplicate filename '/class/ide_port/ide0'

[<fffffc00003308a0>] __warn+0x160/0x190
[<fffffc000048c9f4>] sysfs_warn_dup+0x94/0xd0
[<fffffc0000330928>] warn_slowpath_fmt+0x58/0x70
[<fffffc000048c9f4>] sysfs_warn_dup+0x94/0xd0
[<fffffc0000486d40>] kernfs_path_from_node+0x30/0x60
[<fffffc00004874ac>] kernfs_put+0x16c/0x2c0
[<fffffc00004874ac>] kernfs_put+0x16c/0x2c0
[<fffffc000048d010>] sysfs_do_create_link_sd.isra.2+0x100/0x120
[<fffffc00005b9d64>] device_add+0x2a4/0x7c0
[<fffffc00005ba5cc>] device_create_groups_vargs+0x14c/0x170
[<fffffc00005ba518>] device_create_groups_vargs+0x98/0x170
[<fffffc00005ba690>] device_create+0x50/0x70
[<fffffc00005df36c>] ide_host_register+0x48c/0xa00
[<fffffc00005df330>] ide_host_register+0x450/0xa00
[<fffffc00005ba2a0>] device_register+0x20/0x50
[<fffffc00005df330>] ide_host_register+0x450/0xa00
[<fffffc00005df944>] ide_host_add+0x64/0xe0
[<fffffc000079b41c>] kobject_uevent_env+0x16c/0x710
[<fffffc0000310288>] do_one_initcall+0x68/0x260
[<fffffc00007b13bc>] kernel_init+0x1c/0x1a0
[<fffffc00007b13a0>] kernel_init+0x0/0x1a0
[<fffffc0000311868>] ret_from_kernel_thread+0x18/0x20
[<fffffc00007b13a0>] kernel_init+0x0/0x1a0

---[ end trace 24a70433c3e4d374 ]---
ide0: disabling port

Fix the IRQ allocation issue by adding a pci_assign_irq() call in the
ide_scan_pcidev() function before probing the IDE PCI drivers, so that
IRQs for a given PCI device are allocated for the IDE PCI drivers to
use them for device configuration.

Fixes: 30fdfb929e82 ("PCI: Add a call to pci_assign_irq() in pci_device_probe()")
Link: http://lkml.kernel.org/r/32ec730f-c1b0-5584-cd35-f8a809122b96@xxxxxxxxxxxx
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
Reported-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Cc: Richard Henderson <rth@xxxxxxxxxxx>
Cc: Ivan Kokshaysky <ink@xxxxxxxxxxxxxxxxxxxx>
Cc: David S. Miller <davem@xxxxxxxxxxxxx>
Cc: Guenter Roeck <linux@xxxxxxxxxxxx>
Cc: Matt Turner <mattst88@xxxxxxxxx>

- Moved fix from PCI core code to IDE subsystem following further
debugging and mailing list discussions
- Rebased against v4.14-rc3

drivers/ide/ide-scan-pci.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/ide/ide-scan-pci.c b/drivers/ide/ide-scan-pci.c
index 86aa88a..acf8748 100644
--- a/drivers/ide/ide-scan-pci.c
+++ b/drivers/ide/ide-scan-pci.c
@@ -56,6 +56,7 @@ static int __init ide_scan_pcidev(struct pci_dev *dev)
struct list_head *l;
struct pci_driver *d;
+ int ret;

list_for_each(l, &ide_pci_drivers) {
d = list_entry(l, struct pci_driver, node);
@@ -63,10 +64,14 @@ static int __init ide_scan_pcidev(struct pci_dev *dev)
const struct pci_device_id *id =
pci_match_id(d->id_table, dev);

- if (id != NULL && d->probe(dev, id) >= 0) {
- dev->driver = d;
- pci_dev_get(dev);
- return 1;
+ if (id != NULL) {
+ pci_assign_irq(dev);
+ ret = d->probe(dev, id);
+ if (ret >= 0) {
+ dev->driver = d;
+ pci_dev_get(dev);
+ return 1;
+ }