From 99bbdfa6bdcb4bdf5be914a48e9b46941bf30819 Mon Sep 17 00:00:00 2001 From: Anthony Foiani Date: Mon, 19 Aug 2013 19:20:30 -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: [] sata_fsl_interrupt+0x50/0x250 [ 9.123137] {HARDIRQ-ON-W} state was registered at: [ 9.128004] [] lock_acquire+0x90/0xf4 [ 9.132737] [] _raw_spin_lock+0x34/0x4c [ 9.137645] [] fsl_sata_set_irq_coalescing+0x68/0x100 [ 9.143750] [] sata_fsl_init_controller+0xa8/0xc0 [ 9.149505] [] sata_fsl_probe+0x17c/0x2e8 [ 9.154568] [] driver_probe_device+0x90/0x248 [ 9.159987] [] __driver_attach+0xc4/0xc8 [ 9.164964] [] bus_for_each_dev+0x5c/0xa8 [ 9.170028] [] bus_add_driver+0x100/0x26c [ 9.175091] [] driver_register+0x88/0x198 [ 9.180155] [] do_one_initcall+0x58/0x1b4 [ 9.185226] [] kernel_init_freeable+0x118/0x1c0 [ 9.190823] [] kernel_init+0x18/0x108 [ 9.195542] [] ret_from_kernel_thread+0x64/0x6c [ 9.201142] irq event stamp: 160 [ 9.204366] hardirqs last enabled at (159): [] _raw_spin_unlock_irq+0x30/0x50 [ 9.212469] hardirqs last disabled at (160): [] reenable_mmu+0x30/0x88 [ 9.219867] softirqs last enabled at (144): [] __do_softirq+0x168/0x218 [ 9.227435] softirqs last disabled at (137): [] 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] [ 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 , and was discussed in email at: http://linuxppc.10917.n7.nabble.com/MPC8315-reboot-failure-lockdep-splat-possibly-related-tp75162.html Same patch successfully tested with 3.9.7. linux-next compiled but not tested on hardware. This patch is based off linux-next tag next-20130819 (which is commit 66a01bae29d11916c09f9f5a937cafe7d402e4a5 ) Signed-off-by: Anthony Foiani Signed-off-by: Tejun Heo Cc: stable@vger.kernel.org --- 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 19720a0a4a65..851bd3f43ac6 100644 --- a/drivers/ata/sata_fsl.c +++ b/drivers/ata/sata_fsl.c @@ -293,6 +293,7 @@ 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; @@ -305,12 +306,12 @@ 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("interrupt coalescing, count = 0x%x, ticks = %x\n", intr_coalescing_count, intr_coalescing_ticks); -- 2.30.2