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

[ Upstream commit 12a7f17fac5b370bec87259e4c718faf563ce900 ]

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>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/dwc3/dwc3-omap.c b/drivers/usb/dwc3/dwc3-omap.c
index 5dd1832..35b6351 100644 (file)
--- a/drivers/usb/dwc3/dwc3-omap.c
+++ b/drivers/usb/dwc3/dwc3-omap.c
@@ -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>
@@ -511,7 +512,7 @@ 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);
@@ -532,7 +533,7 @@ static int dwc3_omap_probe(struct platform_device *pdev)
        }
 
        dwc3_omap_enable_irqs(omap);
-
+       enable_irq(omap->irq);
        return 0;
 
 err2:
@@ -553,6 +554,7 @@ 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);