[PATCH 3.16.y-ckt 053/165] usb: XHCI: platform: Move the Marvell quirks after the enabling the clocks

[Luis Henriques]

3.16.7-ckt9 -stable review patch.  If anyone has any objections, please let me know.

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

From: Maxime Ripard <maxime.ripard at free-electrons.com>

commit 1e7e4fb66489cc84366656ca5318f1cb61afd4ba upstream.

The commit 973747928514 ("usb: host: xhci-plat: add support for the Armada
375/38x XHCI controllers") extended the xhci-plat driver to support the Armada
375/38x SoCs, mostly by adding a quirk configuring the MBUS window.

However, that quirk was run before the clock the controllers needs has been
enabled. This usually worked because the clock was first enabled by the
bootloader, and left as such until the driver is probe, where it tries to
access the MBUS configuration registers before enabling the clock.

Things get messy when EPROBE_DEFER is involved during the probe, since as part
of its error path, the driver will rightfully disable the clock. When the
driver will be reprobed, it will retry to access the MBUS registers, but this
time with the clock disabled, which hangs forever.

Fix this by running the quirks after the clock has been enabled by the driver.

Signed-off-by: Maxime Ripard <maxime.ripard at free-electrons.com>
Signed-off-by: Mathias Nyman <mathias.nyman at linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/usb/host/xhci-plat.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
index 271690de8de1..bbf86db713ce 100644
--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c
@@ -115,15 +115,6 @@ static int xhci_plat_probe(struct platform_device *pdev)
 	if (!res)
 		return -ENODEV;
 
-	if (of_device_is_compatible(pdev->dev.of_node,
-				    "marvell,armada-375-xhci") ||
-	    of_device_is_compatible(pdev->dev.of_node,
-				    "marvell,armada-380-xhci")) {
-		ret = xhci_mvebu_mbus_init_quirk(pdev);
-		if (ret)
-			return ret;
-	}
-
 	/* Initialize dma_mask and coherent_dma_mask to 32-bits */
 	ret = dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(32));
 	if (ret)
@@ -165,6 +156,15 @@ static int xhci_plat_probe(struct platform_device *pdev)
 			goto unmap_registers;
 	}
 
+	if (of_device_is_compatible(pdev->dev.of_node,
+				    "marvell,armada-375-xhci") ||
+	    of_device_is_compatible(pdev->dev.of_node,
+				    "marvell,armada-380-xhci")) {
+		ret = xhci_mvebu_mbus_init_quirk(pdev);
+		if (ret)
+			goto disable_clk;
+	}
+
 	ret = usb_add_hcd(hcd, irq, IRQF_SHARED);
 	if (ret)
 		goto disable_clk;