MPC8315 reboot failure, lockdep splat possibly related?
Bhushan Bharat-R65777
R65777 at freescale.com
Mon Aug 19 03:00:25 EST 2013
> -----Original Message-----
> From: Anthony Foiani [mailto:tkil at scrye.com]
> Sent: Sunday, August 18, 2013 5:37 AM
> To: Bhushan Bharat-R65777
> Cc: linuxppc-dev at lists.ozlabs.org
> Subject: Re: MPC8315 reboot failure, lockdep splat possibly related?
>
> Bhushan Bharat-R65777 <R65777 at freescale.com> writes:
>
> > You should get rid of this by changing spin_lock/unlock() in
> > fsl_sata_set_irq_coalescing() to spin_lock_irqsave/restore()
>
> I can verify that the suggested change removes the lockdep warning.
> The below patch is against 3.9.7 and has been tested on hardware with that
> release.
>
> It applies with slight fuzz to linux-next; I've compile-tested that version, but
> I have not booted that build on the hardware. The linux-next patch can be found
> here:
>
> http://scrye.com/~tkil/linux/fsl-sata-lockdep-201308/next-sata-fsl-save-irqs-
> while-coalescing.patch
> (or: http://preview.tinyurl.com/mpd4e9h )
Anthony, I would prefer if you can send the patch (In case not then let me know)
Thanks
-Bharat
>
> Unfortunately, the hang on reboot was not easily repeatable; I'll report whether
> it happens in the next few days or not.
>
> Thanks again,
> Anthony Foiani
>
> -- >8 --
>
> From 2abb6df770c95eb4103476c70847a78f816fe5e3 Mon Sep 17 00:00:00 2001
> From: Anthony Foiani <anthony.foiani at gmail.com>
> Date: Sat, 17 Aug 2013 13:28:17 -0600
> Subject: [PATCH] sata: fsl: save irqs while coalescing
>
> Before this patch, I was seeing the following lockdep splat on my
> MPC8315 (PPC32) target:
>
> [ 9.086051] =================================
> [ 9.090393] [ INFO: inconsistent lock state ]
> [ 9.094744] 3.9.7-ajf-gc39503d #1 Not tainted
> [ 9.099087] ---------------------------------
> [ 9.103432] inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage.
> [ 9.109431] scsi_eh_1/39 [HC1[1]:SC0[0]:HE0:SE1] takes:
> [ 9.114642] (&(&host->lock)->rlock){?.+...}, at: [<c02f4168>]
> sata_fsl_interrupt+0x50/0x250
> [ 9.123137] {HARDIRQ-ON-W} state was registered at:
> [ 9.128004] [<c006cdb8>] lock_acquire+0x90/0xf4
> [ 9.132737] [<c043ef04>] _raw_spin_lock+0x34/0x4c
> [ 9.137645] [<c02f3560>] fsl_sata_set_irq_coalescing+0x68/0x100
> [ 9.143750] [<c02f36a0>] sata_fsl_init_controller+0xa8/0xc0
> [ 9.149505] [<c02f3f10>] sata_fsl_probe+0x17c/0x2e8
> [ 9.154568] [<c02acc90>] driver_probe_device+0x90/0x248
> [ 9.159987] [<c02acf0c>] __driver_attach+0xc4/0xc8
> [ 9.164964] [<c02aae74>] bus_for_each_dev+0x5c/0xa8
> [ 9.170028] [<c02ac218>] bus_add_driver+0x100/0x26c
> [ 9.175091] [<c02ad638>] driver_register+0x88/0x198
> [ 9.180155] [<c0003a24>] do_one_initcall+0x58/0x1b4
> [ 9.185226] [<c05aeeac>] kernel_init_freeable+0x118/0x1c0
> [ 9.190823] [<c0004110>] kernel_init+0x18/0x108
> [ 9.195542] [<c000f6b8>] ret_from_kernel_thread+0x64/0x6c
> [ 9.201142] irq event stamp: 160
> [ 9.204366] hardirqs last enabled at (159): [<c043f778>]
> _raw_spin_unlock_irq+0x30/0x50
> [ 9.212469] hardirqs last disabled at (160): [<c000f414>]
> reenable_mmu+0x30/0x88
> [ 9.219867] softirqs last enabled at (144): [<c002ae5c>]
> __do_softirq+0x168/0x218
> [ 9.227435] softirqs last disabled at (137): [<c002b0d4>]
> irq_exit+0xa8/0xb4
> [ 9.234481]
> [ 9.234481] other info that might help us debug this:
> [ 9.240995] Possible unsafe locking scenario:
> [ 9.240995]
> [ 9.246898] CPU0
> [ 9.249337] ----
> [ 9.251776] lock(&(&host->lock)->rlock);
> [ 9.255878] <Interrupt>
> [ 9.258492] lock(&(&host->lock)->rlock);
> [ 9.262765]
> [ 9.262765] *** DEADLOCK ***
> [ 9.262765]
> [ 9.268684] no locks held by scsi_eh_1/39.
> [ 9.272767]
> [ 9.272767] stack backtrace:
> [ 9.277117] Call Trace:
> [ 9.279589] [cfff9da0] [c0008504] show_stack+0x48/0x150 (unreliable)
> [ 9.285972] [cfff9de0] [c0447d5c] print_usage_bug.part.35+0x268/0x27c
> [ 9.292425] [cfff9e10] [c006ace4] mark_lock+0x2ac/0x658
> [ 9.297660] [cfff9e40] [c006b7e4] __lock_acquire+0x754/0x1840
> [ 9.303414] [cfff9ee0] [c006cdb8] lock_acquire+0x90/0xf4
> [ 9.308745] [cfff9f20] [c043ef04] _raw_spin_lock+0x34/0x4c
> [ 9.314250] [cfff9f30] [c02f4168] sata_fsl_interrupt+0x50/0x250
> [ 9.320187] [cfff9f70] [c0079ff0] handle_irq_event_percpu+0x90/0x254
> [ 9.326547] [cfff9fc0] [c007a1fc] handle_irq_event+0x48/0x78
> [ 9.332220] [cfff9fe0] [c007c95c] handle_level_irq+0x9c/0x104
> [ 9.337981] [cfff9ff0] [c000d978] call_handle_irq+0x18/0x28
> [ 9.343568] [cc7139f0] [c000608c] do_IRQ+0xf0/0x1a8
> [ 9.348464] [cc713a20] [c000fc8c] ret_from_except+0x0/0x14
> [ 9.353983] --- Exception: 501 at _raw_spin_unlock_irq+0x40/0x50
> [ 9.353983] LR = _raw_spin_unlock_irq+0x30/0x50
> [ 9.364839] [cc713af0] [c043db10] wait_for_common+0xac/0x188
> [ 9.370513] [cc713b30] [c02ddee4] ata_exec_internal_sg+0x2b0/0x4f0
> [ 9.376699] [cc713be0] [c02de18c] ata_exec_internal+0x68/0xa8
> [ 9.382454] [cc713c20] [c02de4b8] ata_dev_read_id+0x158/0x594
> [ 9.388205] [cc713ca0] [c02ec244] ata_eh_recover+0xd88/0x13d0
> [ 9.393962] [cc713d20] [c02f2520] sata_pmp_error_handler+0xc0/0x8ac
> [ 9.400234] [cc713dd0] [c02ecdc8] ata_scsi_port_error_handler+0x464/0x5e8
> [ 9.407023] [cc713e10] [c02ecfd0] ata_scsi_error+0x84/0xb8
> [ 9.412528] [cc713e40] [c02c4974] scsi_error_handler+0xd8/0x47c
> [ 9.418457] [cc713eb0] [c004737c] kthread+0xa8/0xac
> [ 9.423355] [cc713f40] [c000f6b8] ret_from_kernel_thread+0x64/0x6c
>
> This fix was suggested by Bhushan Bharat <R65777 at freescale.com>, and was
> discussed in email at:
>
> http://linuxppc.10917.n7.nabble.com/MPC8315-reboot-failure-lockdep-splat-
> possibly-related-tp75162.html
>
> Signed-off-by: Anthony Foiani <anthony.foiani at gmail.com>
> ---
> drivers/ata/sata_fsl.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/ata/sata_fsl.c b/drivers/ata/sata_fsl.c index
> 0e93ba9..c240b63 100644
> --- a/drivers/ata/sata_fsl.c
> +++ b/drivers/ata/sata_fsl.c
> @@ -292,6 +292,7 @@ static void fsl_sata_set_irq_coalescing(struct ata_host
> *host, {
> struct sata_fsl_host_priv *host_priv = host->private_data;
> void __iomem *hcr_base = host_priv->hcr_base;
> + unsigned long flags;
>
> if (count > ICC_MAX_INT_COUNT_THRESHOLD)
> count = ICC_MAX_INT_COUNT_THRESHOLD;
> @@ -304,12 +305,12 @@ static void fsl_sata_set_irq_coalescing(struct ata_host
> *host,
> (count > ICC_MIN_INT_COUNT_THRESHOLD))
> ticks = ICC_SAFE_INT_TICKS;
>
> - spin_lock(&host->lock);
> + spin_lock_irqsave(&host->lock, flags);
> iowrite32((count << 24 | ticks), hcr_base + ICC);
>
> intr_coalescing_count = count;
> intr_coalescing_ticks = ticks;
> - spin_unlock(&host->lock);
> + spin_unlock_irqrestore(&host->lock, flags);
>
> DPRINTK("intrrupt coalescing, count = 0x%x, ticks = %x\n",
> intr_coalescing_count, intr_coalescing_ticks);
> --
> 1.8.1.4
>
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