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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        Grygorii Strashko <grygorii.strashko@ti.com>,
        Vignesh R <vigneshr@ti.com>,
        Felipe Balbi <felipe.balbi@linux.intel.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.9 081/171] usb: dwc3: omap: remove IRQ_NOAUTOEN used with shared irq
Date:   Thu,  8 Nov 2018 13:50:51 -0800
Message-Id: <20181108215133.398471864@linuxfoundation.org>
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4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

[ Upstream commit ee249b4554947de3be77be4e9e6077b20c0fe055 ]

IRQ_NOAUTOEN cannot be used with shared IRQs, since commit 04c848d39879
("genirq: Warn when IRQ_NOAUTOEN is used with shared interrupts") and
kernel now throws a warn dump. But OMAP DWC3 driver uses this flag. As
per commit 12a7f17fac5b ("usb: dwc3: omap: fix race of pm runtime with
irq handler in probe") that introduced this flag, PM runtime can race
with IRQ handler when deferred probing happens due to extcon,
therefore IRQ_NOAUTOEN needs to be set so that irq is not enabled until
extcon is registered.

Remove setting of IRQ_NOAUTOEN and move the registration of
shared irq to a point after dwc3_omap_extcon_register() and
of_platform_populate(). This avoids possibility of probe deferring and
above said race condition.

Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/usb/dwc3/dwc3-omap.c | 18 ++++++++----------
 1 file changed, 8 insertions(+), 10 deletions(-)

diff --git a/drivers/usb/dwc3/dwc3-omap.c b/drivers/usb/dwc3/dwc3-omap.c
index f221cb479e14..8e69150776f5 100644
--- a/drivers/usb/dwc3/dwc3-omap.c
+++ b/drivers/usb/dwc3/dwc3-omap.c
@@ -512,15 +512,6 @@ 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);
-	if (ret) {
-		dev_err(dev, "failed to request IRQ #%d --> %d\n",
-				omap->irq, ret);
-		goto err1;
-	}
 
 	ret = dwc3_omap_extcon_register(omap);
 	if (ret < 0)
@@ -532,8 +523,15 @@ static int dwc3_omap_probe(struct platform_device *pdev)
 		goto err2;
 	}
 
+	ret = devm_request_threaded_irq(dev, omap->irq, dwc3_omap_interrupt,
+					dwc3_omap_interrupt_thread, IRQF_SHARED,
+					"dwc3-omap", omap);
+	if (ret) {
+		dev_err(dev, "failed to request IRQ #%d --> %d\n",
+			omap->irq, ret);
+		goto err1;
+	}
 	dwc3_omap_enable_irqs(omap);
-	enable_irq(omap->irq);
 	return 0;
 
 err2:
-- 
2.17.1