From: Fabio Estevam <fabio.estevam@xxxxxxxxxxxxx>
Remove the locking inside sdhci_do_set_ios() to avoid the following warning:
======================================================
[ 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
Signed-off-by: Fabio Estevam <fabio.estevam@xxxxxxxxxxxxx>
---
This is running linux-next 20131112 on a mx6q wandboard.
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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