ipr and "Badness at kernel/lockdep.c:2193"

Hi Brian,

Booting one of our JS21 blades with 2.6.28-rc7 leads to the following:

ipr: IBM Power RAID SCSI Device Driver version: 2.4.1 (April 24, 2007) ipr 0000:01:01.0: Found IOA with IRQ: 26
ipr 0000:01:01.0: Starting IOA initialization sequence.
ipr 0000:01:01.0: Adapter firmware version: 06160039
ipr 0000:01:01.0: IOA initialized.

------------[ cut here ]------------
Badness at kernel/lockdep.c:2193
NIP: c0000000000855d0 LR: c0000000000855b4 CTR: c0000000000482d0
REGS: c00000000fffb8d0 TRAP: 0700   Not tainted  (2.6.28-rc5-autokern1)
MSR: 8000000000021032 <ME,IR,DR>  CR: 28000022  XER: 00000004

TASK = c00000000091fa80[0] 'swapper' THREAD: c000000000a3c000 CPU: 0
GPR00: 0000000000000000 c00000000fffbb50 c000000000a3c2e0 0000000000000001
GPR04: 000000000000a580 c0000000003870d4 0000000000000000 0000000000000001
GPR08: 0000000000000000 c00000000112fdf0 c0000000008ed918 c000000000abcfd0
GPR12: 0000000048000088 c000000000a7f300 0000000000000000 0000000002100000
GPR16: c000000000644bd0 c000000000643390 0000000000000000 00000000003d0c00
GPR20: 00000000028372d8 c0000000007372d8 0000000002837548 c000000000737548
GPR24: c000000000644660 00000000028372d8 000000000000001a c000000076760000
GPR28: 0000000000000004 c0000000004e8450 c0000000009aafb0 c00000000091fa80 NIP [c0000000000855d0] .trace_hardirqs_on_caller+0x10c/0x194 LR [c0000000000855b4] .trace_hardirqs_on_caller+0xf0/0x194

Call Trace:

[c00000000fffbb50] [c00000000fffbbe0] 0xc00000000fffbbe0 (unreliable) [c00000000fffbbe0] [c0000000004e8450] ._spin_unlock_irq+0x38/0x5c [c00000000fffbc70] [c0000000003870d4] .ipr_ioa_reset_done+0x204/0x284 [c00000000fffbd10] [c00000000037d234] .ipr_reset_ioa_job+0xc4/0xec [c00000000fffbda0] [c000000000385ce0] .ipr_isr+0x208/0x484 [c00000000fffbe50] [c0000000000aaf3c] .handle_IRQ_event+0x58/0xd4 [c00000000fffbef0] [c0000000000ad978] .handle_fasteoi_irq+0x110/0x1ac [c00000000fffbf90] [c000000000025214] .call_handle_irq+0x1c/0x2c [c000000000a3f9a0] [c00000000000d168] .do_IRQ+0x120/0x210 [c000000000a3fa40] [c000000000004804] hardware_interrupt_entry+0x1c/0x98 --- Exception: 501 at .pseries_dedicated_idle_sleep+0xec/0x1cc

    LR = .pseries_dedicated_idle_sleep+0xdc/0x1cc

[c000000000a3fd30] [c000000000038208] .pseries_dedicated_idle_sleep+0x74/0x1cc (unreliable) [c000000000a3fdd0] [c000000000012134] .cpu_idle+0x114/0x1dc [c000000000a3fe60] [c0000000004ecb18] .rest_init+0x7c/0x94 [c000000000a3fee0] [c000000000700a40] .start_kernel+0x4b8/0x4e0 [c000000000a3ff90] [c000000000008368] .start_here_common+0x1c/0x34 Instruction dump:
e92d01b0 80090894 2f800000 41be002c 481ed1d1 60000000 2fa30000 419e0080 e93e8090 80090000 2f800000 409e0070 <0fe00000> 48000068 7fe3fb78 38800001 scsi0 : IBM 572E Storage Adapter
scsi 0:0:1:0: Direct-Access IBM-ESXS MAY2036RC T106 PQ: 0 ANSI: 5
scsi: unknown device type 31
scsi 0:255:255:255: No Device IBM 572E001 0150 PQ: 0 ANSI: 0
vio_register_driver: driver ibmvscsi registering
st: Version 20080504, fixed bufsize 32768, s/g segs 256
Driver 'st' needs updating - please use bus_type methods
Driver 'sd' needs updating - please use bus_type methods
sd 0:0:1:0: [sda] 71096640 512-byte hardware sectors: (36.4 GB/33.9 GiB)
sd 0:0:1:0: [sda] Write Protect is off
sd 0:0:1:0: [sda] Mode Sense: d7 00 00 08
sd 0:0:1:0: [sda] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA sd 0:0:1:0: [sda] 71096640 512-byte hardware sectors: (36.4 GB/33.9 GiB)
sd 0:0:1:0: [sda] Write Protect is off
sd 0:0:1:0: [sda] Mode Sense: d7 00 00 08
sd 0:0:1:0: [sda] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA
sda: sda1 sda2 sda3 sda4 < sda5 sda6 sda7 sda8 >
sd 0:0:1:0: [sda] Attached SCSI disk
Driver 'sr' needs updating - please use bus_type methods
sd 0:0:1:0: Attached scsi generic sg0 type 0
scsi 0:255:255:255: Attached scsi generic sg1 type 31

Is this an issue with the ipr driver or a lockdep issue?

Thanks!

Mark

To fix the following lockdep warning we turn the spin_unlock_irq() into a spin_unlock() and similarly for the corresponding spin_lock_irq(). We can do this because there is no need to enable interrupts in this path (thanks to Bring King for the tip).

Badness at kernel/lockdep.c:2193
NIP: c0000000000855d0 LR: c0000000000855b4 CTR: c0000000000482d0
REGS: c00000000fffb8d0 TRAP: 0700 Not tainted (2.6.28-rc5-autokern1)
MSR: 8000000000021032 <ME,IR,DR> CR: 28000022 XER: 00000004 TASK = c00000000091fa80[0] 'swapper' THREAD: c000000000a3c000 CPU: 0
GPR00: 0000000000000000 c00000000fffbb50 c000000000a3c2e0 0000000000000001
GPR04: 000000000000a580 c0000000003870d4 0000000000000000 0000000000000001
GPR08: 0000000000000000 c00000000112fdf0 c0000000008ed918 c000000000abcfd0
GPR12: 0000000048000088 c000000000a7f300 0000000000000000 0000000002100000
GPR16: c000000000644bd0 c000000000643390 0000000000000000 00000000003d0c00
GPR20: 00000000028372d8 c0000000007372d8 0000000002837548 c000000000737548
GPR24: c000000000644660 00000000028372d8 000000000000001a c000000076760000
GPR28: 0000000000000004 c0000000004e8450 c0000000009aafb0 c00000000091fa80 NIP [c0000000000855d0] .trace_hardirqs_on_caller+0x10c/0x194 LR [c0000000000855b4] .trace_hardirqs_on_caller+0xf0/0x194

Call Trace:

[c00000000fffbb50] [c00000000fffbbe0] 0xc00000000fffbbe0 (unreliable) [c00000000fffbbe0] [c0000000004e8450] ._spin_unlock_irq+0x38/0x5c [c00000000fffbc70] [c0000000003870d4] .ipr_ioa_reset_done+0x204/0x284 [c00000000fffbd10] [c00000000037d234] .ipr_reset_ioa_job+0xc4/0xec [c00000000fffbda0] [c000000000385ce0] .ipr_isr+0x208/0x484 [c00000000fffbe50] [c0000000000aaf3c] .handle_IRQ_event+0x58/0xd4 [c00000000fffbef0] [c0000000000ad978] .handle_fasteoi_irq+0x110/0x1ac [c00000000fffbf90] [c000000000025214] .call_handle_irq+0x1c/0x2c [c000000000a3f9a0] [c00000000000d168] .do_IRQ+0x120/0x210 [c000000000a3fa40] [c000000000004804] hardware_interrupt_entry+0x1c/0x98 --- Exception: 501 at .pseries_dedicated_idle_sleep+0xec/0x1cc

    LR = .pseries_dedicated_idle_sleep+0xdc/0x1cc

[c000000000a3fd30] [c000000000038208] .pseries_dedicated_idle_sleep+0x74/0x1cc (unreliable) [c000000000a3fdd0] [c000000000012134] .cpu_idle+0x114/0x1dc [c000000000a3fe60] [c0000000004ecb18] .rest_init+0x7c/0x94 [c000000000a3fee0] [c000000000700a40] .start_kernel+0x4b8/0x4e0 [c000000000a3ff90] [c000000000008368] .start_here_common+0x1c/0x34 Instruction dump:
e92d01b0 80090894 2f800000 41be002c 481ed1d1 60000000 2fa30000 419e0080 e93e8090 80090000 2f800000 409e0070 <0fe00000> 48000068 7fe3fb78 38800001

Signed-off-by Mark Nelson <[email protected]>

---
Is this patch OK? It makes silences the warning and so far has no side effects

 drivers/scsi/ipr.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Index: upstream/drivers/scsi/ipr.c
===================================================================

drivers/scsi/ipr.c +2 -3

@@ -5389,9 +5389,9 @@ static int ipr_ioa_reset_done(struct ipr
 	list_add_tail(&ipr_cmd->queue, &ioa_cfg->free_q);
 	wake_up_all(&ioa_cfg->reset_wait_q);
 
-	spin_unlock_irq(ioa_cfg->host->host_lock);
+	spin_unlock(ioa_cfg->host->host_lock);
 	scsi_unblock_requests(ioa_cfg->host);
-	spin_lock_irq(ioa_cfg->host->host_lock);
+	spin_lock(ioa_cfg->host->host_lock);
 
 	if (!ioa_cfg->allow_cmds)
 		scsi_block_requests(ioa_cfg->host);
--

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