usb: dwc3: move synchronize_irq() out of the spinlock protected block

mszyprow · Felipe Balbi · commit 41a91c606e7d · 2019-05-03T09:13:48.000+03:00
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 foundriesio#1: b5fe1270 (&of->mutex){+.+.}, at: kernfs_fop_write+0xc0/0x1e4 foundriesio#2: 7e597705 (kn->count#60){.+.+}, at: kernfs_fop_write+0xc8/0x1e4 foundriesio#3: 8b3527d0 (system_transition_mutex){+.+.}, at: pm_suspend+0xc4/0xc04 foundriesio#4: fc7f1c42 (&dev->mutex){....}, at: __device_suspend+0xd8/0x74c foundriesio#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) ... Fixes: 01c1088 ("usb: dwc3: gadget: synchronize_irq dwc irq in suspend") Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
@@ -1603,6 +1603,7 @@ 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:
@@ -1635,6 +1636,7 @@ 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
@@ -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;
 }
 

Original file line number	Diff line number	Diff line change
`@@ -3384,8 +3384,6 @@ int dwc3_gadget_suspend(struct dwc3 *dwc)`
`3384`	`3384`	`dwc3_disconnect_gadget(dwc);`
`3385`	`3385`	`__dwc3_gadget_stop(dwc);`
`3386`	`3386`
`3387`		`- synchronize_irq(dwc->irq_gadget);`
`3388`		`-`
`3389`	`3387`	`return 0;`
`3390`	`3388`	`}`
`3391`	`3389`