Hi Fabio,
On Thu, Nov 28, 2013 at 8:47 AM, Fabio Estevam <feste...@gmail.com> wrote:
> From: Fabio Estevam <fabio.este...@freescale.com>
>
> Remove the locking inside sdhci_do_set_ios() to avoid the following warning:
>
Simply remove locks in sdhci_do_set_ios is too rude and is not the correct fix.
The right approach should be avoid accessing hardirq-unsafe lock in
IMX .set_clock
funcion.
I will push a correct fix with you CCed.
Regards
Dong Aisheng
> ======================================================
> [ INFO: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected ]
> fec 2188000.ethernet eth0: Freescale FEC PHY driver [Generic PHY]
> (mii_bus:phy_)
> IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready
> 3.12.0-next-20131112+ #446 Not tainted
> ------------------------------------------------------
> kworker/u8:1/29 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire:
> (prepare_lock){+.+.+.}, at: [<80476cdc>] clk_prepare_lock+0x78/0xec
>
> and this task is already holding:
> (&(&host->lock)->rlock#2){-.-...}, at: [<80457e5c>]
> sdhci_do_set_ios+0x20/0x708
> which would create a new lock dependency:
> (&(&host->lock)->rlock#2){-.-...} -> (prepare_lock){+.+.+.}
>
> but this new dependency connects a HARDIRQ-irq-safe lock:
> (&(&host->lock)->rlock#2){-.-...}
> ... which became HARDIRQ-irq-safe at:
> [<8005e3e4>] mark_lock+0x140/0x6a8
> [<8005f410>] __lock_acquire+0xac4/0x1c1c
> [<80060a34>] lock_acquire+0x68/0x7c
> [<8060a988>] _raw_spin_lock+0x30/0x40
> [<80456e00>] sdhci_irq+0x24/0xa10
> [<8006a204>] handle_irq_event_percpu+0x54/0x1a4
> [<8006a398>] handle_irq_event+0x44/0x64
> [<8006d4c0>] handle_fasteoi_irq+0xa0/0x160
> [<80069b78>] generic_handle_irq+0x28/0x38
> [<8000f358>] handle_IRQ+0x54/0xb8
> [<80008640>] gic_handle_irq+0x30/0x64
> [<800130a4>] __irq_svc+0x44/0x5c
> [<806026e0>] printk+0x38/0x40
> [<80458e24>] sdhci_add_host+0x844/0xbd0
> [<8045ab48>] sdhci_esdhc_imx_probe+0x31c/0x5dc
> [<80325dc4>] platform_drv_probe+0x20/0x50
> [<803247b4>] driver_probe_device+0x118/0x234
> [<8032496c>] __driver_attach+0x9c/0xa0
> [<80322d78>] bus_for_each_dev+0x5c/0x90
> [<803242b0>] driver_attach+0x20/0x28
> [<80323eac>] bus_add_driver+0xdc/0x1dc
> [<80325024>] driver_register+0x80/0xfc
> [<80325ce4>] __platform_driver_register+0x50/0x64
> [<8083a6b0>] sdhci_esdhc_imx_driver_init+0x18/0x20
> [<80008974>] do_one_initcall+0xfc/0x160
> [<8080bc9c>] kernel_init_freeable+0x104/0x1d4
> [<805ff7e0>] kernel_init+0x10/0x120
> [<8000eae8>] ret_from_fork+0x14/0x2c
>
> to a HARDIRQ-irq-unsafe lock:
> (prepare_lock){+.+.+.}
> ... which became HARDIRQ-irq-unsafe at:
> ... [<8005e3e4>] mark_lock+0x140/0x6a8
> [<800611f0>] mark_held_locks+0x64/0x130
> [<8006136c>] trace_hardirqs_on_caller+0xb0/0x1cc
> [<8006149c>] trace_hardirqs_on+0x14/0x18
> [<806078f8>] mutex_trylock+0x178/0x200
> [<80476c78>] clk_prepare_lock+0x14/0xec
> [<80477818>] clk_notifier_register+0x28/0xf4
> [<8001537c>] twd_clk_init+0x50/0x68
> [<80008974>] do_one_initcall+0xfc/0x160
> [<8080bc9c>] kernel_init_freeable+0x104/0x1d4
> [<805ff7e0>] kernel_init+0x10/0x120
> [<8000eae8>] ret_from_fork+0x14/0x2c
>
> other info that might help us debug this:
>
> Possible interrupt unsafe locking scenario:
>
> CPU0 CPU1
> ---- ----
> lock(prepare_lock);
> local_irq_disable();
> lock(&(&host->lock)->rlock#2);
> lock(prepare_lock);
> <Interrupt>
> lock(&(&host->lock)->rlock#2);
>
> *** DEADLOCK ***
>
> 3 locks held by kworker/u8:1/29:
> #0: (kmmcd){.+.+..}, at: [<8003d0e8>] process_one_work+0x130/0x450
> #1: ((&(&host->detect)->work)){+.+...}, at: [<8003d0e8>]
> process_one_work+0x10
> #2: (&(&host->lock)->rlock#2){-.-...}, at: [<80457e5c>]
> sdhci_do_set_ios+0x208
>
> the dependencies between HARDIRQ-irq-safe lock and the holding lock:
> -> (&(&host->lock)->rlock#2){-.-...} ops: 930 {
> IN-HARDIRQ-W at:
> [<8005e3e4>] mark_lock+0x140/0x6a8
> [<8005f410>] __lock_acquire+0xac4/0x1c1c
> [<80060a34>] lock_acquire+0x68/0x7c
> [<8060a988>] _raw_spin_lock+0x30/0x40
> [<80456e00>] sdhci_irq+0x24/0xa10
> [<8006a204>] handle_irq_event_percpu+0x54/0x1a4
> [<8006a398>] handle_irq_event+0x44/0x64
> [<8006d4c0>] handle_fasteoi_irq+0xa0/0x160
> [<80069b78>] generic_handle_irq+0x28/0x38
> [<8000f358>] handle_IRQ+0x54/0xb8
> [<80008640>] gic_handle_irq+0x30/0x64
> [<800130a4>] __irq_svc+0x44/0x5c
> [<806026e0>] printk+0x38/0x40
> [<80458e24>] sdhci_add_host+0x844/0xbd0
> [<8045ab48>] sdhci_esdhc_imx_probe+0x31c/0x5dc
> [<80325dc4>] platform_drv_probe+0x20/0x50
> [<803247b4>] driver_probe_device+0x118/0x234
> [<8032496c>] __driver_attach+0x9c/0xa0
> [<80322d78>] bus_for_each_dev+0x5c/0x90
> [<803242b0>] driver_attach+0x20/0x28
> [<80323eac>] bus_add_driver+0xdc/0x1dc
> [<80325024>] driver_register+0x80/0xfc
> [<80325ce4>] __platform_driver_register+0x50/0x64
> [<8083a6b0>] sdhci_esdhc_imx_driver_init+0x18/0x20
> [<80008974>] do_one_initcall+0xfc/0x160
> [<8080bc9c>] kernel_init_freeable+0x104/0x1d4
> [<805ff7e0>] kernel_init+0x10/0x120
> [<8000eae8>] ret_from_fork+0x14/0x2c
> IN-SOFTIRQ-W at:
> [<8005e3e4>] mark_lock+0x140/0x6a8
> [<8005ee1c>] __lock_acquire+0x4d0/0x1c1c
> [<80060a34>] lock_acquire+0x68/0x7c
> [<8060aa5c>] _raw_spin_lock_irqsave+0x40/0x54
> [<80454b20>] sdhci_tasklet_finish+0x1c/0x11c
> [<8002ad64>] tasklet_action+0x90/0x148
> [<8002b2c8>] __do_softirq+0x100/0x25c
> [<8002b800>] irq_exit+0xb0/0x104
> [<8000f35c>] handle_IRQ+0x58/0xb8
> [<80008640>] gic_handle_irq+0x30/0x64
> [<800130a4>] __irq_svc+0x44/0x5c
> [<806026e0>] printk+0x38/0x40
> [<80458e24>] sdhci_add_host+0x844/0xbd0
> [<8045ab48>] sdhci_esdhc_imx_probe+0x31c/0x5dc
> [<80325dc4>] platform_drv_probe+0x20/0x50
> [<803247b4>] driver_probe_device+0x118/0x234
> [<8032496c>] __driver_attach+0x9c/0xa0
> [<80322d78>] bus_for_each_dev+0x5c/0x90
> [<803242b0>] driver_attach+0x20/0x28
> [<80323eac>] bus_add_driver+0xdc/0x1dc
> [<80325024>] driver_register+0x80/0xfc
> [<80325ce4>] __platform_driver_register+0x50/0x64
> [<8083a6b0>] sdhci_esdhc_imx_driver_init+0x18/0x20
> [<80008974>] do_one_initcall+0xfc/0x160
> [<8080bc9c>] kernel_init_freeable+0x104/0x1d4
> [<805ff7e0>] kernel_init+0x10/0x120
> [<8000eae8>] ret_from_fork+0x14/0x2c
> INITIAL USE at:
> [<8005e3e4>] mark_lock+0x140/0x6a8
> [<8005ec14>] __lock_acquire+0x2c8/0x1c1c
> [<80060a34>] lock_acquire+0x68/0x7c
> [<8060aa5c>] _raw_spin_lock_irqsave+0x40/0x54
> [<80457e5c>] sdhci_do_set_ios+0x20/0x708
> [<8045856c>] sdhci_set_ios+0x28/0x34
> [<80443990>] mmc_power_up+0x6c/0xd0
> [<804446d4>] mmc_start_host+0x40/0x64
> [<80445704>] mmc_add_host+0x60/0x88
> [<80458dd8>] sdhci_add_host+0x7f8/0xbd0
> [<8045ab48>] sdhci_esdhc_imx_probe+0x31c/0x5dc
> [<80325dc4>] platform_drv_probe+0x20/0x50
> [<803247b4>] driver_probe_device+0x118/0x234
> [<8032496c>] __driver_attach+0x9c/0xa0
> [<80322d78>] bus_for_each_dev+0x5c/0x90
> [<803242b0>] driver_attach+0x20/0x28
> [<80323eac>] bus_add_driver+0xdc/0x1dc
> [<80325024>] driver_register+0x80/0xfc
> [<80325ce4>] __platform_driver_register+0x50/0x64
> [<8083a6b0>] sdhci_esdhc_imx_driver_init+0x18/0x20
> [<80008974>] do_one_initcall+0xfc/0x160
> [<8080bc9c>] kernel_init_freeable+0x104/0x1d4
> [<805ff7e0>] kernel_init+0x10/0x120
> [<8000eae8>] ret_from_fork+0x14/0x2c
> }
> ... key at: [<80df3da4>] __key.27058+0x0/0x8
> ... acquired at:
> [<8005df14>] check_usage+0x3c8/0x5b8
> [<8005e160>] check_irq_usage+0x5c/0xb8
> [<8005f794>] __lock_acquire+0xe48/0x1c1c
> [<80060a34>] lock_acquire+0x68/0x7c
> [<806093bc>] mutex_lock_nested+0x54/0x3ac
> [<80476cdc>] clk_prepare_lock+0x78/0xec
> [<80477920>] clk_get_rate+0x14/0x64
> [<80459edc>] esdhc_pltfm_set_clock+0x20/0x294
> [<80454754>] sdhci_set_clock+0x4c/0x3fc
> [<80457f28>] sdhci_do_set_ios+0xec/0x708
> [<8045856c>] sdhci_set_ios+0x28/0x34
> [<80442d24>] __mmc_set_clock+0x44/0x60
> [<8044383c>] mmc_set_clock+0x10/0x14
> [<8044b56c>] mmc_sdio_init_card+0x4a8/0xa70
> [<8044c004>] mmc_attach_sdio+0x88/0x370
> [<80444604>] mmc_rescan+0x230/0x2c0
> [<8003d164>] process_one_work+0x1ac/0x450
> [<8003d808>] worker_thread+0x124/0x398
> [<80044684>] kthread+0xcc/0xe8
> [<8000eae8>] ret_from_fork+0x14/0x2c
>
>
> the dependencies between the lock to be acquired and HARDIRQ-irq-unsafe lock:
> -> (prepare_lock){+.+.+.} ops: 380 {
> HARDIRQ-ON-W at:
> [<8005e3e4>] mark_lock+0x140/0x6a8
> [<800611f0>] mark_held_locks+0x64/0x130
> [<8006136c>] trace_hardirqs_on_caller+0xb0/0x1cc
> [<8006149c>] trace_hardirqs_on+0x14/0x18
> [<806078f8>] mutex_trylock+0x178/0x200
> [<80476c78>] clk_prepare_lock+0x14/0xec
> [<80477818>] clk_notifier_register+0x28/0xf4
> [<8001537c>] twd_clk_init+0x50/0x68
> [<80008974>] do_one_initcall+0xfc/0x160
> [<8080bc9c>] kernel_init_freeable+0x104/0x1d4
> [<805ff7e0>] kernel_init+0x10/0x120
> [<8000eae8>] ret_from_fork+0x14/0x2c
> SOFTIRQ-ON-W at:
> [<8005e3e4>] mark_lock+0x140/0x6a8
> [<800611f0>] mark_held_locks+0x64/0x130
> [<800613b0>] trace_hardirqs_on_caller+0xf4/0x1cc
> [<8006149c>] trace_hardirqs_on+0x14/0x18
> [<806078f8>] mutex_trylock+0x178/0x200
> [<80476c78>] clk_prepare_lock+0x14/0xec
> [<80477818>] clk_notifier_register+0x28/0xf4
> [<8001537c>] twd_clk_init+0x50/0x68
> [<80008974>] do_one_initcall+0xfc/0x160
> [<8080bc9c>] kernel_init_freeable+0x104/0x1d4
> [<805ff7e0>] kernel_init+0x10/0x120
> [<8000eae8>] ret_from_fork+0x14/0x2c
> RECLAIM_FS-ON-W at:
> [<8005e3e4>] mark_lock+0x140/0x6a8
> [<800611f0>] mark_held_locks+0x64/0x130
> [<80061a2c>] lockdep_trace_alloc+0x90/0x100
> [<800a6408>] __alloc_pages_nodemask+0x7c/0x818
> [<800d5054>] new_slab+0x6c/0x270
> [<80603564>]
> __slab_alloc.isra.56.constprop.58+0x1bc/0x54
> [<800d56c0>] kmem_cache_alloc+0xf4/0x124
> [<800f0a8c>] __d_alloc+0x24/0x184
> [<800f0df8>] d_alloc+0x18/0x68
> [<800e3e90>] lookup_dcache+0x8c/0xac
> [<800e3ed0>] __lookup_hash+0x20/0x4c
> [<800e8708>] lookup_one_len+0xcc/0x120
> [<802531f8>] __create_file+0x70/0x1dc
> [<80253438>] debugfs_create_file+0x30/0x38
> [<802541e4>] debugfs_create_u32+0x44/0x54
> [<80477c60>] clk_debug_create_subtree+0xb0/0x118
> [<8083bc78>] clk_debug_init+0xb0/0x140
> [<80008974>] do_one_initcall+0xfc/0x160
> [<8080bc9c>] kernel_init_freeable+0x104/0x1d4
> [<805ff7e0>] kernel_init+0x10/0x120
> [<8000eae8>] ret_from_fork+0x14/0x2c
> INITIAL USE at:
> [<8005e3e4>] mark_lock+0x140/0x6a8
> [<8005ec14>] __lock_acquire+0x2c8/0x1c1c
> [<80060a34>] lock_acquire+0x68/0x7c
> [<80607890>] mutex_trylock+0x110/0x200
> [<80476c78>] clk_prepare_lock+0x14/0xec
> [<80478bd8>] __clk_init+0x1c/0x45c
> [<804790e8>] _clk_register+0xd0/0x168
> [<80479230>] clk_register+0x3c/0x84
> [<80479bd4>] clk_register_fixed_rate+0x88/0xd4
> [<80479c88>] of_fixed_clk_setup+0x68/0x90
> [<8083bd4c>] of_clk_init+0x44/0x6c
> [<8080f2e4>] time_init+0x2c/0x38
> [<8080ba10>] start_kernel+0x1dc/0x364
> [<10008074>] 0x10008074
> }
> ... key at: [<8089f47c>] prepare_lock+0x38/0x48
> ... acquired at:
> [<8005df48>] check_usage+0x3fc/0x5b8
> [<8005e160>] check_irq_usage+0x5c/0xb8
> [<8005f794>] __lock_acquire+0xe48/0x1c1c
> [<80060a34>] lock_acquire+0x68/0x7c
> [<806093bc>] mutex_lock_nested+0x54/0x3ac
> [<80476cdc>] clk_prepare_lock+0x78/0xec
> [<80477920>] clk_get_rate+0x14/0x64
> [<80459edc>] esdhc_pltfm_set_clock+0x20/0x294
> [<80454754>] sdhci_set_clock+0x4c/0x3fc
> [<80457f28>] sdhci_do_set_ios+0xec/0x708
> [<8045856c>] sdhci_set_ios+0x28/0x34
> [<80442d24>] __mmc_set_clock+0x44/0x60
> [<8044383c>] mmc_set_clock+0x10/0x14
> [<8044b56c>] mmc_sdio_init_card+0x4a8/0xa70
> [<8044c004>] mmc_attach_sdio+0x88/0x370
> [<80444604>] mmc_rescan+0x230/0x2c0
> [<8003d164>] process_one_work+0x1ac/0x450
> [<8003d808>] worker_thread+0x124/0x398
> [<80044684>] kthread+0xcc/0xe8
> [<8000eae8>] ret_from_fork+0x14/0x2c
>
>
> stack backtrace:
> CPU: 1 PID: 29 Comm: kworker/u8:1 Not tainted 3.12.0-next-20131112+ #446
> Workqueue: kmmcd mmc_rescan
> Backtrace:
> [<8001233c>] (dump_backtrace+0x0/0x10c) from [<800124d8>]
> (show_stack+0x18/0x1c)
> r6:00000000 r5:80967f70 r4:00000000 r3:ef1d9b00
> [<800124c0>] (show_stack+0x0/0x1c) from [<80604564>] (dump_stack+0x80/0x9c)
> [<806044e4>] (dump_stack+0x0/0x9c) from [<8005df68>] (check_usage+0x41c/0x5b8)
> r4:ef215b2c r3:ef1d9b00
> [<8005db4c>] (check_usage+0x0/0x5b8) from [<8005e160>]
> (check_irq_usage+0x5c/0x)
> [<8005e104>] (check_irq_usage+0x0/0xb8) from [<8005f794>]
> (__lock_acquire+0xe48)
> r8:80de9504 r7:00000003 r6:80d9f334 r5:80950a80 r4:ef1d9ed0
> [<8005e94c>] (__lock_acquire+0x0/0x1c1c) from [<80060a34>]
> (lock_acquire+0x68/0)
> [<800609cc>] (lock_acquire+0x0/0x7c) from [<806093bc>]
> (mutex_lock_nested+0x54/)
> r7:ef1d9b00 r6:80d9f334 r5:00000000 r4:80476cdc
> [<80609368>] (mutex_lock_nested+0x0/0x3ac) from [<80476cdc>]
> (clk_prepare_lock+)
> [<80476c64>] (clk_prepare_lock+0x0/0xec) from [<80477920>]
> (clk_get_rate+0x14/0)
> r6:02faf080 r5:ee9192a8 r4:ef027300 r3:8089d6cc
> [<8047790c>] (clk_get_rate+0x0/0x64) from [<80459edc>]
> (esdhc_pltfm_set_clock+0)
> r5:ee9192a8 r4:ee919440
> [<80459ebc>] (esdhc_pltfm_set_clock+0x0/0x294) from [<80454754>]
> (sdhci_set_clo)
> [<80454708>] (sdhci_set_clock+0x0/0x3fc) from [<80457f28>]
> (sdhci_do_set_ios+0x)
> [<80457e3c>] (sdhci_do_set_ios+0x0/0x708) from [<8045856c>]
> (sdhci_set_ios+0x28)
> [<80458544>] (sdhci_set_ios+0x0/0x34) from [<80442d24>]
> (__mmc_set_clock+0x44/0)
> r5:02faf080 r4:ee919000
> [<80442ce0>] (__mmc_set_clock+0x0/0x60) from [<8044383c>]
> (mmc_set_clock+0x10/0)
> r5:ef278800 r4:ee919000
> [<8044382c>] (mmc_set_clock+0x0/0x14) from [<8044b56c>]
> (mmc_sdio_init_card+0x4)
> [<8044b0c4>] (mmc_sdio_init_card+0x0/0xa70) from [<8044c004>]
> (mmc_attach_sdio+)
> [<8044bf7c>] (mmc_attach_sdio+0x0/0x370) from [<80444604>]
> (mmc_rescan+0x230/0x)
> [<804443d4>] (mmc_rescan+0x0/0x2c0) from [<8003d164>]
> (process_one_work+0x1ac/0)
> r8:00000000 r7:ef215ea8 r6:ef00dc00 r5:ee9192f8 r4:ef1ea980
> r3:804443d4
> [<8003cfb8>] (process_one_work+0x0/0x450) from [<8003d808>]
> (worker_thread+0x12)
> [<8003d6e4>] (worker_thread+0x0/0x398) from [<80044684>] (kthread+0xcc/0xe8)
> [<800445b8>] (kthread+0x0/0xe8) from [<8000eae8>] (ret_from_fork+0x14/0x2c)
> r7:00000000 r6:00000000 r5:800445b8 r4:ef1eca80
>
> Tested-by: Markus Niebel <markus.nie...@tqs.de>
> Signed-off-by: Fabio Estevam <fabio.este...@freescale.com>
> ---
> This warning does not happen during all boots. It happens in around 20% of the
> boots.
>
> Searching on other set_ios implementations, I see that they do not hold
> spin lock.
>
> drivers/mmc/host/sdhci.c | 12 +-----------
> 1 file changed, 1 insertion(+), 11 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index bd8a098..ba6f630 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -1412,14 +1412,10 @@ static void sdhci_request(struct mmc_host *mmc,
> struct mmc_request *mrq)
>
> static void sdhci_do_set_ios(struct sdhci_host *host, struct mmc_ios *ios)
> {
> - unsigned long flags;
> int vdd_bit = -1;
> u8 ctrl;
>
> - spin_lock_irqsave(&host->lock, flags);
> -
> if (host->flags & SDHCI_DEVICE_DEAD) {
> - spin_unlock_irqrestore(&host->lock, flags);
> if (host->vmmc && ios->power_mode == MMC_POWER_OFF)
> mmc_regulator_set_ocr(host->mmc, host->vmmc, 0);
> return;
> @@ -1446,11 +1442,8 @@ static void sdhci_do_set_ios(struct sdhci_host *host,
> struct mmc_ios *ios)
> else
> vdd_bit = sdhci_set_power(host, ios->vdd);
>
> - if (host->vmmc && vdd_bit != -1) {
> - spin_unlock_irqrestore(&host->lock, flags);
> + if (host->vmmc && vdd_bit != -1)
> mmc_regulator_set_ocr(host->mmc, host->vmmc, vdd_bit);
> - spin_lock_irqsave(&host->lock, flags);
> - }
>
> if (host->ops->platform_send_init_74_clocks)
> host->ops->platform_send_init_74_clocks(host,
> ios->power_mode);
> @@ -1584,9 +1577,6 @@ static void sdhci_do_set_ios(struct sdhci_host *host,
> struct mmc_ios *ios)
> */
> if(host->quirks & SDHCI_QUIRK_RESET_CMD_DATA_ON_IOS)
> sdhci_reset(host, SDHCI_RESET_CMD | SDHCI_RESET_DATA);
> -
> - mmiowb();
> - spin_unlock_irqrestore(&host->lock, flags);
> }
>
> static void sdhci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
> --
> 1.8.1.2
>
> --
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