With CONFIG_DEBUG_SHIRQ enabled, the irq tear down routine
would still access the irq handler registed as a shard irq.
Per the comment within the function of __free_irq, it says
"It's a shared IRQ -- the driver ought to be prepared for
an IRQ event to happen even now it's being freed". However
when failing to probe the driver, dw_mmc disables the clock
and asserts the reset pin, even power off its genpd for accessing
the registers and the following check for shared irq state would call
the irq handler which accesses the register w/o all necessary resouce
prepared. That will hang the system forever.
With adding some dump_stack we could see how that happened.
Synopsys Designware Multimedia Card Interface Driver
dwmmc_rockchip fe320000.dwmmc: IDMAC supports 32-bit address mode.
dwmmc_rockchip fe320000.dwmmc: Using internal DMA controller.
dwmmc_rockchip fe320000.dwmmc: Version ID is 270a
CPU: 0 PID: 1 Comm: swapper/0 Not tainted
4.13.0-rc3-next-20170807-00004-g93d3644-dirty #5
Hardware name: Firefly-RK3399 Board (DT)
Call trace:
[<ffff20000808b5a0>] dump_backtrace+0x0/0x300
[<ffff20000808ba1c>] show_stack+0x14/0x20
[<ffff200008dc480c>] dump_stack+0xa4/0xc8
[<ffff200008b9691c>] dw_mci_interrupt+0x3c/0x6a8
[<ffff200008157450>] __free_irq+0x308/0x410
[<ffff20000815760c>] free_irq+0x54/0xb0
[<ffff20000815d630>] devm_irq_release+0x30/0x40
[<ffff2000087f0174>] release_nodes+0x1e4/0x390
[<ffff2000087f04c0>] devres_release_all+0x50/0x78
[<ffff2000087e9bc0>] driver_probe_device+0x128/0x3b8
[<ffff2000087e9f34>] __driver_attach+0xe4/0xe8
[<ffff2000087e7048>] bus_for_each_dev+0xe0/0x138
[<ffff2000087e93b8>] driver_attach+0x30/0x40
[<ffff2000087e8c00>] bus_add_driver+0x1d0/0x328
[<ffff2000087ead0c>] driver_register+0xb4/0x198
[<ffff2000087ec98c>] __platform_driver_register+0x7c/0x88
[<ffff2000095bc564>] dw_mci_rockchip_pltfm_driver_init+0x18/0x20
[<ffff200008083a8c>] do_one_initcall+0x14c/0x1b8
[<ffff200009560ff8>] kernel_init_freeable+0x238/0x2d8
[<ffff200008dde500>] kernel_init+0x10/0x110
[<ffff2000080836c0>] ret_from_fork+0x10/0x50
Synchronous External Abort: synchronous external abort (0x96000010) at
0xffff20000aaa4040
Internal error: : 96000010 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 1 Comm: swapper/0 Not tainted
task: ffff80006ba28080 task.stack: ffff80006ba24000
PC is at dw_mci_interrupt+0x4c/0x6a8
LR is at dw_mci_interrupt+0x44/0x6a8
pc : [<ffff200008b9692c>] lr : [<ffff200008b96924>] pstate: 600001c5
...
Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b
SMP: stopping secondary CPUs
Kernel Offset: disabled
CPU features: 0x00200c
Memory Limit: none
---[ end Kernel panic - not syncing: Attempted to kill init!
exitcode=0x0000000b
In order to fix this, we remove all the clock-disabling from
the error handle path and driver's remove function. And replying
on the devm_add_action_or_reset to fire the clock-disabling and reset
signal at the appropriate time.
*However*!!!
However, it still can't stop the device's dismiss callback to fire
the genpd_power_off_work_fn, which still would power off the genpd and
break the system. More precisely, the genpd power off races with the
devres's release as they are totally asynchronous, so sometimes the system
is alive due to the race contition. See the following case:
rockchip fe320000.dwmmc: IDMAC supports 32-bit address mode.
dwmmc_rockchip fe320000.dwmmc: Using internal DMA controller.
dwmmc_rockchip fe320000.dwmmc: Version ID is 270a
CPU: 0 PID: 39 Comm: kworker/0:1 Not tainted
4.13.0-rc3-next-20170807-00004-g93d3644-dirty #20
dw_mci_interrupt enter //action from free_irq
dw_mci_post_cleanup enter //dw_mmc's devm action callback
dwmmc_rockchip: probe of fe320000.dwmmc failed with error -12
rockchip_pd_power: power_off //luckly power off genpd here
Hardware name: Firefly-RK3399 Board (DT)
Workqueue: pm genpd_power_off_work_fn
Call trace:
[<ffff20000808b5a0>] dump_backtrace+0x0/0x300
sdhci-pltfm: SDHCI platform and OF driver helper
[<ffff20000808ba1c>] show_stack+0x14/0x20
[<ffff200008dc480c>] dump_stack+0xa4/0xc8
[<ffff20000871e3b8>] rockchip_pd_power+0x640/0x648
[<ffff20000871ec38>] rockchip_pd_power_off+0x10/0x18
[<ffff200008809614>] genpd_power_off+0x19c/0x388
[<ffff20000880a3dc>] genpd_power_off_work_fn+0x4c/0x80
[<ffff200008104560>] process_one_work+0x388/0x5e0
[<ffff20000810483c>] worker_thread+0x84/0x680
[<ffff20000810d90c>] kthread+0x18c/0x1d0
[<ffff2000080836c0>] ret_from_fork+0x10/0x50
Signed-off-by: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>
---
Dear Ulf and Rafael,
I have poor knowledge about power_domain and haven't find the
right solution to fix this problem for genpd part after reading the
power domain code. Moreover, I don't think it's dw_mmc specific as
the issue I found seems widely exists in all different kinds of
drivers. So I would appreciate if you could kindly point me to the
right direction. :)
drivers/mmc/host/dw_mmc.c | 48 +++++++++++++++++++++++------------------------
1 file changed, 23 insertions(+), 25 deletions(-)
diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index b9640c7..05b5acf 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -3012,6 +3012,18 @@ static void dw_mci_enable_cd(struct dw_mci *host)
}
}
+static void dw_mci_post_cleanup(void *data)
+{
+ struct dw_mci *host = data;
+
+ clk_disable_unprepare(host->ciu_clk);
+ clk_disable_unprepare(host->biu_clk);
+
+ if (!IS_ERR(host->pdata->rstc))
+ reset_control_assert(host->pdata->rstc);
+
+}
+
int dw_mci_probe(struct dw_mci *host)
{
const struct dw_mci_drv_data *drv_data = host->drv_data;
@@ -3047,7 +3059,7 @@ int dw_mci_probe(struct dw_mci *host)
ret = clk_prepare_enable(host->ciu_clk);
if (ret) {
dev_err(host->dev, "failed to enable ciu clock\n");
- goto err_clk_biu;
+ return ret;
}
if (host->pdata->bus_hz) {
@@ -3060,11 +3072,16 @@ int dw_mci_probe(struct dw_mci *host)
host->bus_hz = clk_get_rate(host->ciu_clk);
}
+ ret = devm_add_action_or_reset(host->dev, dw_mci_post_cleanup, host);
+ if (ret) {
+ dev_err(host->dev, "unable to add action or reset\n");
+ return ret;
+ }
+
if (!host->bus_hz) {
dev_err(host->dev,
"Platform data must supply bus speed\n");
- ret = -ENODEV;
- goto err_clk_ciu;
+ return -ENODEV;
}
if (drv_data && drv_data->init) {
@@ -3072,7 +3089,7 @@ int dw_mci_probe(struct dw_mci *host)
if (ret) {
dev_err(host->dev,
"implementation specific init failed\n");
- goto err_clk_ciu;
+ return ret;
}
}
@@ -3119,10 +3136,8 @@ int dw_mci_probe(struct dw_mci *host)
}
/* Reset all blocks */
- if (!dw_mci_ctrl_reset(host, SDMMC_CTRL_ALL_RESET_FLAGS)) {
- ret = -ENODEV;
- goto err_clk_ciu;
- }
+ if (!dw_mci_ctrl_reset(host, SDMMC_CTRL_ALL_RESET_FLAGS))
+ return -ENODEV;
host->dma_ops = host->pdata->dma_ops;
dw_mci_init_dma(host);
@@ -3209,15 +3224,6 @@ int dw_mci_probe(struct dw_mci *host)
if (host->use_dma && host->dma_ops->exit)
host->dma_ops->exit(host);
- if (!IS_ERR(host->pdata->rstc))
- reset_control_assert(host->pdata->rstc);
-
-err_clk_ciu:
- clk_disable_unprepare(host->ciu_clk);
-
-err_clk_biu:
- clk_disable_unprepare(host->biu_clk);
-
return ret;
}
EXPORT_SYMBOL(dw_mci_probe);
@@ -3237,17 +3243,9 @@ void dw_mci_remove(struct dw_mci *host)
if (host->use_dma && host->dma_ops->exit)
host->dma_ops->exit(host);
-
- if (!IS_ERR(host->pdata->rstc))
- reset_control_assert(host->pdata->rstc);
-
- clk_disable_unprepare(host->ciu_clk);
- clk_disable_unprepare(host->biu_clk);
}
EXPORT_SYMBOL(dw_mci_remove);
-
-
#ifdef CONFIG_PM
int dw_mci_runtime_suspend(struct device *dev)
{
--
1.9.1
--
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