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usb: dwc3: omap: fix race of pm runtime with irq handler in probe

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Now races can happen between interrupt handler execution and PM runtime in
error handling code path in probe and in dwc3_omap_remove() which will lead
to system crash:

in probe:
...
 err1:
	pm_runtime_put_sync(dev);
^^ PM runtime can race with IRQ handler when deferred probing happening
   due to extcon
	pm_runtime_disable(dev);

	return ret;

in dwc3_omap_remove:
...
	dwc3_omap_disable_irqs(omap);
^^ IRQs are disabled in HW, but handler may still run
	of_platform_depopulate(omap->dev);
	pm_runtime_put_sync(&pdev->dev);
^^ PM runtime can race with IRQ handler
	pm_runtime_disable(&pdev->dev);

	return 0;

So, OMAP DWC3 IRQ need to be disabled before calling
pm_runtime_put() in probe and in dwc3_omap_remove().

Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
This commit is contained in:
Grygorii Strashko 2016-12-12 13:37:52 -06:00 committed by Felipe Balbi
parent 890e6c236d
commit 12a7f17fac
1 changed files with 4 additions and 2 deletions
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6
drivers/usb/dwc3/dwc3-omap.c
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@ -19,6 +19,7 @@
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/platform_data/dwc3-omap.h>
@ -510,7 +511,7 @@ static int dwc3_omap_probe(struct platform_device *pdev)
/* check the DMA Status */
reg = dwc3_omap_readl(omap->base, USBOTGSS_SYSCONFIG);
irq_set_status_flags(omap->irq, IRQ_NOAUTOEN);
ret = devm_request_threaded_irq(dev, omap->irq, dwc3_omap_interrupt,
dwc3_omap_interrupt_thread, IRQF_SHARED,
"dwc3-omap", omap);
@ -531,7 +532,7 @@ static int dwc3_omap_probe(struct platform_device *pdev)
}
dwc3_omap_enable_irqs(omap);
enable_irq(omap->irq);
return 0;
err2:
@ -552,6 +553,7 @@ static int dwc3_omap_remove(struct platform_device *pdev)
extcon_unregister_notifier(omap->edev, EXTCON_USB, &omap->vbus_nb);
extcon_unregister_notifier(omap->edev, EXTCON_USB_HOST, &omap->id_nb);
dwc3_omap_disable_irqs(omap);
disable_irq(omap->irq);
of_platform_depopulate(omap->dev);
pm_runtime_put_sync(&pdev->dev);
pm_runtime_disable(&pdev->dev);