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

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>
hifive-unleashed-5.1
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
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
drivers/usb/dwc3/dwc3-omap.c
View File

@ -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);