[3.8.y.z extended stable] Patch "usb: musb: only cancel work if it is initialized" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    usb: musb: only cancel work if it is initialized

to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue

This patch is scheduled to be released in version 3.8.13.16.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.8.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 8e32ddc2fb290811c2b517c867e07487e09230e2 Mon Sep 17 00:00:00 2001
From: Sebastian Andrzej Siewior <bigeasy at linutronix.de>
Date: Wed, 6 Nov 2013 09:25:27 +0100
Subject: usb: musb: only cancel work if it is initialized

commit 66fadea5b79c07154126bb0db375be915f611246 upstream.

Since commit c5340bd14 ("usb: musb: cancel work on removal") the workqueue
is cancelled but then if we bail out before the workqueue is setup we
get this:

|INFO: trying to register non-static key.
|the code is fine but needs lockdep annotation.
|turning off the locking correctness validator.
|CPU: 0 PID: 708 Comm: modprobe Not tainted 3.12.0+ #435
|[<c00867bc>] (lock_acquire+0xf0/0x108) from [<c00529d0>] (flush_work+0x38/0x2ec)
|[<c00529d0>] (flush_work+0x38/0x2ec) from [<c0052d24>] (__cancel_work_timer+0xa0/0x134)
|[<c0052d24>] (__cancel_work_timer+0xa0/0x134) from [<bf0e4ae4>] (musb_free+0x40/0x60 [musb_hdrc])
|[<bf0e4ae4>] (musb_free+0x40/0x60 [musb_hdrc]) from [<bf0e5364>] (musb_probe+0x678/0xb78 [musb_hdrc])
|[<bf0e5364>] (musb_probe+0x678/0xb78 [musb_hdrc]) from [<c0294bf0>] (platform_drv_probe+0x1c/0x24)
|[<c0294bf0>] (platform_drv_probe+0x1c/0x24) from [<c0293970>] (driver_probe_device+0x90/0x224)
|[<c0293970>] (driver_probe_device+0x90/0x224) from [<c0291ef0>] (bus_for_each_drv+0x60/0x8c)
|[<c0291ef0>] (bus_for_each_drv+0x60/0x8c) from [<c02938bc>] (device_attach+0x80/0xa4)
|[<c02938bc>] (device_attach+0x80/0xa4) from [<c0292b24>] (bus_probe_device+0x88/0xac)
|[<c0292b24>] (bus_probe_device+0x88/0xac) from [<c0291490>] (device_add+0x388/0x6c8)
|[<c0291490>] (device_add+0x388/0x6c8) from [<c02952a0>] (platform_device_add+0x188/0x22c)
|[<c02952a0>] (platform_device_add+0x188/0x22c) from [<bf11ea30>] (dsps_probe+0x294/0x394 [musb_dsps])
|[<bf11ea30>] (dsps_probe+0x294/0x394 [musb_dsps]) from [<c0294bf0>] (platform_drv_probe+0x1c/0x24)
|platform musb-hdrc.1.auto: Driver musb-hdrc requests probe deferral
|musb-hdrc musb-hdrc.1.auto: musb_init_controller failed with status -517

This patch moves the init part to earlier part so it can be cleaned as
part of the fail3 label because now it is surrounded by the fail4 label.
Step two is to remove it from musb_free() and add it to the two cleanup
paths (error path and device removal) separately.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy at linutronix.de>
Signed-off-by: Felipe Balbi <balbi at ti.com>
[ kamal: backport to 3.8 (context) ]
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/usb/musb/musb_core.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
index 85b7a91..dd4fe41 100644
--- a/drivers/usb/musb/musb_core.c
+++ b/drivers/usb/musb/musb_core.c
@@ -1816,7 +1816,6 @@ static void musb_free(struct musb *musb)
 			disable_irq_wake(musb->nIrq);
 		free_irq(musb->nIrq, musb);
 	}
-	cancel_work_sync(&musb->irq_work);
 	if (is_dma_capable() && musb->dma_controller) {
 		struct dma_controller	*c = musb->dma_controller;

@@ -1915,6 +1914,9 @@ musb_init_controller(struct device *dev, int nIrq, void __iomem *ctrl)
 	musb_platform_disable(musb);
 	musb_generic_disable(musb);

+	/* Init IRQ workqueue before request_irq */
+	INIT_WORK(&musb->irq_work, musb_irq_work);
+
 	/* setup musb parts of the core (especially endpoints) */
 	status = musb_core_init(plat->config->multipoint
 			? MUSB_CONTROLLER_MHDRC
@@ -1924,9 +1926,6 @@ musb_init_controller(struct device *dev, int nIrq, void __iomem *ctrl)

 	setup_timer(&musb->otg_timer, musb_otg_timer_func, (unsigned long) musb);

-	/* Init IRQ workqueue before request_irq */
-	INIT_WORK(&musb->irq_work, musb_irq_work);
-
 	/* attach to the IRQ */
 	if (request_irq(nIrq, musb->isr, 0, dev_name(dev), musb)) {
 		dev_err(dev, "request_irq %d failed!\n", nIrq);
@@ -1986,6 +1985,7 @@ fail4:
 	musb_gadget_cleanup(musb);

 fail3:
+	cancel_work_sync(&musb->irq_work);
 	pm_runtime_put_sync(musb->controller);

 fail2:
@@ -2050,6 +2050,7 @@ static int musb_remove(struct platform_device *pdev)
 	musb_exit_debugfs(musb);
 	musb_shutdown(pdev);

+	cancel_work_sync(&musb->irq_work);
 	musb_free(musb);
 	iounmap(ctrl_base);
 	device_init_wakeup(dev, 0);
--
1.8.3.2