Okay, I have this working now - there was a hardware problem. However, it's obvious that this has never been tested with lockdep enabled beacuse of the following: disable_irq(host->irq); spin_lock(&host->lock); host->mrq = &mrq; sdhci_send_command(host, mrq.cmd); spin_unlock(&host->lock); enable_irq(host->irq); You can't "work around" stuff like this. Use spin_lock_irq().. spin_unlock_irq(). You can't just disable the interrupt line and expect lockdep to know that it's safe. [ 2.290584] ================================= [ 2.308140] [ INFO: inconsistent lock state ] [ 2.308146] 3.14.0-rc1+ #490 Not tainted [ 2.308148] --------------------------------- [ 2.308152] inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage. [ 2.308158] kworker/u8:0/6 [HC0[0]:SC0[0]:HE1:SE1] takes: [ 2.308191] (&(&host->lock)->rlock#2){?.-...}, at: [<c04b57a4>] esdhc_send_tuning_cmd+0x104/0x14c [ 2.308193] {IN-HARDIRQ-W} state was registered at: [ 2.308215] [<c00652fc>] mark_lock+0x15c/0x6f8 [ 2.308224] [<c0066354>] __lock_acquire+0xabc/0x1ca0 [ 2.308231] [<c0067ad8>] lock_acquire+0xa0/0x130 [ 2.308251] [<c0697a44>] _raw_spin_lock+0x34/0x44 [ 2.308258] [<c04b0dbc>] sdhci_irq+0x20/0xa40 [ 2.308272] [<c0071b1c>] handle_irq_event_percpu+0x74/0x284 [ 2.308278] [<c0071d70>] handle_irq_event+0x44/0x64 [ 2.308289] [<c0074db8>] handle_fasteoi_irq+0xac/0x140 [ 2.308296] [<c007147c>] generic_handle_irq+0x28/0x38 [ 2.308311] [<c000efd4>] handle_IRQ+0x40/0x98 [ 2.308317] [<c0008584>] gic_handle_irq+0x30/0x64 [ 2.308324] [<c0013144>] __irq_svc+0x44/0x58 [ 2.308336] [<c0028fc8>] irq_exit+0xc0/0x120 [ 2.308343] [<c000efd8>] handle_IRQ+0x44/0x98 [ 2.308349] [<c0008584>] gic_handle_irq+0x30/0x64 [ 2.308355] [<c0013144>] __irq_svc+0x44/0x58 [ 2.308363] [<c068f398>] printk+0x3c/0x44 [ 2.308378] [<c03191d0>] _regulator_get+0x1b4/0x1e0 [ 2.308385] [<c031924c>] regulator_get+0x18/0x1c [ 2.308397] [<c049fbc4>] mmc_add_host+0x30/0x1c0 [ 2.308404] [<c04b2e10>] sdhci_add_host+0x804/0xbbc [ 2.308411] [<c04b5318>] sdhci_esdhc_imx_probe+0x380/0x674 [ 2.308427] [<c036d530>] platform_drv_probe+0x20/0x50 [ 2.308435] [<c036b948>] driver_probe_device+0x120/0x234 [ 2.308441] [<c036baf8>] __driver_attach+0x9c/0xa0 [ 2.308448] [<c036a04c>] bus_for_each_dev+0x5c/0x90 [ 2.308455] [<c036b418>] driver_attach+0x24/0x28 [ 2.308462] [<c036b018>] bus_add_driver+0xe4/0x1d8 [ 2.308468] [<c036c1b0>] driver_register+0x80/0xfc [ 2.308477] [<c036ce28>] __platform_driver_register+0x50/0x64 [ 2.308497] [<c093706c>] sdhci_esdhc_imx_driver_init+0x18/0x20 [ 2.308504] [<c0008834>] do_one_initcall+0x3c/0x164 [ 2.308519] [<c0901c94>] kernel_init_freeable+0x104/0x1d0 [ 2.308537] [<c068c45c>] kernel_init+0x10/0x118 [ 2.308546] [<c000e768>] ret_from_fork+0x14/0x2c [ 2.308549] irq event stamp: 5933 [ 2.308560] hardirqs last enabled at (5933): [<c069813c>] _raw_spin_unlock_irqrestore+0x38/0x4c [ 2.308569] hardirqs last disabled at (5932): [<c0697b04>] _raw_spin_lock_irqsave+0x24/0x60 [ 2.308577] softirqs last enabled at (5914): [<c0028ba0>] __do_softirq+0x260/0x360 [ 2.308584] softirqs last disabled at (5909): [<c0028fc8>] irq_exit+0xc0/0x120 [ 2.308586] [ 2.308586] other info that might help us debug this: [ 2.308588] Possible unsafe locking scenario: [ 2.308588] [ 2.308590] CPU0 [ 2.308592] ---- [ 2.308598] lock(&(&host->lock)->rlock#2); [ 2.308600] <Interrupt> [ 2.308606] lock(&(&host->lock)->rlock#2); [ 2.308607] [ 2.308607] *** DEADLOCK *** [ 2.308607] [ 2.308611] 2 locks held by kworker/u8:0/6: [ 2.308626] #0: (kmmcd){.+.+.+}, at: [<c003d890>] process_one_work+0x134/0x4e8 [ 2.308638] #1: ((&(&host->detect)->work)){+.+.+.}, at: [<c003d890>] process_one_work+0x134/0x4e8 [ 2.308640] [ 2.308640] stack backtrace: [ 2.308649] CPU: 2 PID: 6 Comm: kworker/u8:0 Not tainted 3.14.0-rc1+ #490 [ 2.308659] Workqueue: kmmcd mmc_rescan [ 2.308663] Backtrace: [ 2.308679] [<c00124a0>] (dump_backtrace) from [<c0012640>] (show_stack+0x18/0x1c) [ 2.308689] r6:ea07b3e0 r5:ea07af80 r4:00000000 r3:ea07af80 [ 2.308699] [<c0012628>] (show_stack) from [<c069164c>] (dump_stack+0x70/0x8c) [ 2.308707] [<c06915dc>] (dump_stack) from [<c068f080>] (print_usage_bug+0x274/0x2e4) [ 2.308713] r4:c0a8a2c0 r3:ea07af80 [ 2.308723] [<c068ee0c>] (print_usage_bug) from [<c0065774>] (mark_lock+0x5d4/0x6f8) [ 2.308736] r10:ea07af80 r8:ea07af80 r7:00000000 r6:c0a8a2c0 r5:ea07b3e0 r4:00000002 [ 2.308745] [<c00651a0>] (mark_lock) from [<c0065e6c>] (__lock_acquire+0x5d4/0x1ca0) [ 2.308758] r10:ea07af80 r9:00000000 r8:ea07b3e0 r7:e988cd28 r6:00000002 r5:00000460 [ 2.308762] r4:ea07af80 [ 2.308770] [<c0065898>] (__lock_acquire) from [<c0067ad8>] (lock_acquire+0xa0/0x130) [ 2.308783] r10:00000000 r9:00000002 r8:00000000 r7:00000000 r6:e988cd28 r5:ea094000 [ 2.308787] r4:00000000 [ 2.308797] [<c0067a38>] (lock_acquire) from [<c0697a44>] (_raw_spin_lock+0x34/0x44) [ 2.308809] r10:00000006 r9:00000002 r8:00000035 r7:e988cd18 r6:ea095bf8 r5:00000002 [ 2.308813] r4:e988cd18 [ 2.308823] [<c0697a10>] (_raw_spin_lock) from [<c04b57a4>] (esdhc_send_tuning_cmd+0x104/0x14c) [ 2.308829] r5:e988cc40 r4:00000000 [ 2.308838] [<c04b56a0>] (esdhc_send_tuning_cmd) from [<c04b582c>] (esdhc_executing_tuning+0x40/0x100) [ 2.308849] r8:e9878800 r7:00000013 r6:e988cd18 r5:e988cc40 r4:00000000 [ 2.308858] [<c04b57ec>] (esdhc_executing_tuning) from [<c04afa54>] (sdhci_execute_tuning+0xcc/0x754) [ 2.308867] r7:00000000 r6:e988cd18 r5:00000000 r4:e988c800 [ 2.308879] [<c04af988>] (sdhci_execute_tuning) from [<c04a4684>] (mmc_sd_init_card+0x65c/0x694) [ 2.308891] r10:00000006 r9:00000002 r8:e9878800 r7:00000000 r6:e982e700 r5:00000000 [ 2.308895] r4:e988c800 [ 2.308903] [<c04a4028>] (mmc_sd_init_card) from [<c04a48f0>] (mmc_attach_sd+0xb0/0x184) [ 2.308915] r10:ea094000 r8:00000000 r7:c0703e20 r6:e988c800 r5:00000000 r4:e988c800 [ 2.308923] [<c04a4840>] (mmc_attach_sd) from [<c049eb28>] (mmc_rescan+0x26c/0x2e8) [ 2.308929] r5:c0703e14 r4:e988cb08 [ 2.308936] [<c049e8bc>] (mmc_rescan) from [<c003d914>] (process_one_work+0x1b8/0x4e8) [ 2.308946] r7:ea190200 r6:ea00dc00 r5:ea02d980 r4:e988cb08 [ 2.308953] [<c003d75c>] (process_one_work) from [<c003e090>] (worker_thread+0x13c/0x3f8) [ 2.308965] r10:ea094000 r9:00000089 r8:ea02d998 r7:ea094000 r6:ea00dc30 r5:ea00dc00 [ 2.308969] r4:ea02d980 [ 2.308984] [<c003df54>] (worker_thread) from [<c00449bc>] (kthread+0xcc/0xe8) [ 2.308996] r10:00000000 r9:00000000 r8:00000000 r7:c003df54 r6:ea02d980 r5:ea040700 [ 2.309000] r4:00000000 [ 2.309010] [<c00448f0>] (kthread) from [<c000e768>] (ret_from_fork+0x14/0x2c) [ 2.309020] r7:00000000 r6:00000000 r5:c00448f0 r4:ea040700 -- FTTC broadband for 0.8mile line: 5.8Mbps down 500kbps up. Estimation in database were 13.1 to 19Mbit for a good line, about 7.5+ for a bad. Estimate before purchase was "up to 13.2Mbit". -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html