RE: [PATCH 4.20 12/88] usb: dwc3: gadget: synchronize_irq dwc irq in suspend

From: He, Bo
Date: Mon Mar 04 2019 - 03:46:37 EST


Hi, Greg:
Marek Szyprowski report the patch has issue that calling synchronize_irq() under dwc->lock spinlock, he has upload the below patch for the issue:

dwc3_gadget_suspend() is called under dwc->lock spinlock. In such context calling synchronize_irq() is not allowed. Move the problematic call out of the protected block to fix the following kernel BUG during system
suspend:

BUG: sleeping function called from invalid context at kernel/irq/manage.c:112
in_atomic(): 1, irqs_disabled(): 128, pid: 1601, name: rtcwake
6 locks held by rtcwake/1601:
#0: f70ac2a2 (sb_writers#7){.+.+}, at: vfs_write+0x130/0x16c
#1: b5fe1270 (&of->mutex){+.+.}, at: kernfs_fop_write+0xc0/0x1e4
#2: 7e597705 (kn->count#60){.+.+}, at: kernfs_fop_write+0xc8/0x1e4
#3: 8b3527d0 (system_transition_mutex){+.+.}, at: pm_suspend+0xc4/0xc04
#4: fc7f1c42 (&dev->mutex){....}, at: __device_suspend+0xd8/0x74c
#5: 4b36507e (&(&dwc->lock)->rlock){....}, at: dwc3_gadget_suspend+0x24/0x3c irq event stamp: 11252 hardirqs last enabled at (11251): [<c09c54a4>] _raw_spin_unlock_irqrestore+0x6c/0x74
hardirqs last disabled at (11252): [<c09c4d44>] _raw_spin_lock_irqsave+0x1c/0x5c softirqs last enabled at (9744): [<c0102564>] __do_softirq+0x3a4/0x66c softirqs last disabled at (9737): [<c0128528>] irq_exit+0x140/0x168 Preemption disabled at:
[<00000000>] (null)
CPU: 7 PID: 1601 Comm: rtcwake Not tainted
5.0.0-rc3-next-20190122-00039-ga3f4ee4f8a52 #5252 Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) [<c01110f0>] (unwind_backtrace) from [<c010d120>] (show_stack+0x10/0x14) [<c010d120>] (show_stack) from [<c09a4d04>] (dump_stack+0x90/0xc8) [<c09a4d04>] (dump_stack) from [<c014c700>] (___might_sleep+0x22c/0x2c8) [<c014c700>] (___might_sleep) from [<c0189d68>] (synchronize_irq+0x28/0x84) [<c0189d68>] (synchronize_irq) from [<c05cbbf8>] (dwc3_gadget_suspend+0x34/0x3c) [<c05cbbf8>] (dwc3_gadget_suspend) from [<c05bd020>] (dwc3_suspend_common+0x154/0x410) [<c05bd020>] (dwc3_suspend_common) from [<c05bd34c>] (dwc3_suspend+0x14/0x2c) [<c05bd34c>] (dwc3_suspend) from [<c051c730>] (platform_pm_suspend+0x2c/0x54) [<c051c730>] (platform_pm_suspend) from [<c05285d4>] (dpm_run_callback+0xa4/0x3dc) [<c05285d4>] (dpm_run_callback) from [<c0528a40>] (__device_suspend+0x134/0x74c) [<c0528a40>] (__device_suspend) from [<c052c508>] (dpm_suspend+0x174/0x588) [<c052c508>] (dpm_suspend) from [<c0182134>] (suspend_devices_and_enter+0xc0/0xe74)
[<c0182134>] (suspend_devices_and_enter) from [<c0183658>] (pm_suspend+0x770/0xc04) [<c0183658>] (pm_suspend) from [<c0180ddc>] (state_store+0x6c/0xcc) [<c0180ddc>] (state_store) from [<c09a9a70>] (kobj_attr_store+0x14/0x20) [<c09a9a70>] (kobj_attr_store) from [<c02d6800>] (sysfs_kf_write+0x4c/0x50) [<c02d6800>] (sysfs_kf_write) from [<c02d594c>] (kernfs_fop_write+0xfc/0x1e4) [<c02d594c>] (kernfs_fop_write) from [<c02593d8>] (__vfs_write+0x2c/0x160) [<c02593d8>] (__vfs_write) from [<c0259694>] (vfs_write+0xa4/0x16c) [<c0259694>] (vfs_write) from [<c0259870>] (ksys_write+0x40/0x8c) [<c0259870>] (ksys_write) from [<c0101000>] (ret_fast_syscall+0x0/0x28) Exception stack(0xed55ffa8 to 0xed55fff0) ...

Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
---
drivers/usb/dwc3/core.c | 2 ++
drivers/usb/dwc3/gadget.c | 2 --
2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c index a1b126f90261..206d7e5d6d71 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -1600,6 +1600,7 @@ static int dwc3_suspend_common(struct dwc3 *dwc, pm_message_t msg)
spin_lock_irqsave(&dwc->lock, flags);
dwc3_gadget_suspend(dwc);
spin_unlock_irqrestore(&dwc->lock, flags);
+ synchronize_irq(dwc->irq_gadget);
dwc3_core_exit(dwc);
break;
case DWC3_GCTL_PRTCAP_HOST:
@@ -1632,6 +1633,7 @@ static int dwc3_suspend_common(struct dwc3 *dwc, pm_message_t msg)
spin_lock_irqsave(&dwc->lock, flags);
dwc3_gadget_suspend(dwc);
spin_unlock_irqrestore(&dwc->lock, flags);
+ synchronize_irq(dwc->irq_gadget);
}

dwc3_otg_exit(dwc);
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index e293400cc6e9..2bb0ff9608d3 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -3384,8 +3384,6 @@ int dwc3_gadget_suspend(struct dwc3 *dwc)
dwc3_disconnect_gadget(dwc);
__dwc3_gadget_stop(dwc);

- synchronize_irq(dwc->irq_gadget);
-
return 0;
}

--
2.17.1


-----Original Message-----
From: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Sent: Monday, March 4, 2019 4:22 PM
To: linux-kernel@xxxxxxxxxxxxxxx
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>; stable@xxxxxxxxxxxxxxx; He, Bo <bo.he@xxxxxxxxx>; Wang, Yu Y <yu.y.wang@xxxxxxxxx>; Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx>; Sasha Levin <sashal@xxxxxxxxxx>
Subject: [PATCH 4.20 12/88] usb: dwc3: gadget: synchronize_irq dwc irq in suspend

4.20-stable review patch. If anyone has any objections, please let me know.

------------------

[ Upstream commit 01c10880d24291a96a4ab0da773e3c5ce4d12da8 ]

We see dwc3 endpoint stopped by unwanted irq during suspend resume test, which is caused dwc3 ep can't be started with error "No Resource".

Here, add synchronize_irq before suspend to sync the pending IRQ handlers complete.

Signed-off-by: Bo He <bo.he@xxxxxxxxx>
Signed-off-by: Yu Wang <yu.y.wang@xxxxxxxxx>
Signed-off-by: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/usb/dwc3/gadget.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index 5a5b37e0a140f..a7f6255606443 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -3283,6 +3283,8 @@ int dwc3_gadget_suspend(struct dwc3 *dwc)
dwc3_disconnect_gadget(dwc);
__dwc3_gadget_stop(dwc);

+ synchronize_irq(dwc->irq_gadget);
+
return 0;
}

--
2.19.1