linux-kernel - [PATCH V3 1/3] usb: xhci: tegra: Prepare for adding runtime PM support

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Date:   Wed, 16 May 2018 14:48:53 +0100
From:   Jon Hunter <jonathanh@...dia.com>
To:     Mathias Nyman <mathias.nyman@...el.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Thierry Reding <thierry.reding@...il.com>
CC:     <linux-usb@...r.kernel.org>, <linux-tegra@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>, Jon Hunter <jonathanh@...dia.com>
Subject: [PATCH V3 1/3] usb: xhci: tegra: Prepare for adding runtime PM support

When adding runtime PM support to the Tegra XHCI driver, it is desirable
to move the function calls to enable the clocks, regulators and PHY from
the tegra_xusb_probe into the runtime PM handlers. Currently, the
clocks, regulators and PHY are all enabled before we call
usb_create_hcd() in tegra_xusb_probe(), however, we cannot call
pm_runtime_get_sync() at this point because the platform device data is
not yet initialised. Fortunately, the function usb_create_hcd() can be
called before we enable the clocks, regulators and PHY and so prepare
for adding runtime PM support, by moving the call to usb_create_hcd()
before we enable the hardware.

Signed-off-by: Jon Hunter <jonathanh@...dia.com>
Acked-by: Thierry Reding <treding@...dia.com>
---

Changes since V2:
- Add Thierry's ACK

Changes since V1:
- None

 drivers/usb/host/xhci-tegra.c | 34 +++++++++++++++++-----------------
 1 file changed, 17 insertions(+), 17 deletions(-)

diff --git a/drivers/usb/host/xhci-tegra.c b/drivers/usb/host/xhci-tegra.c
index 2c076ea80522..02b0b24faa58 100644
--- a/drivers/usb/host/xhci-tegra.c
+++ b/drivers/usb/host/xhci-tegra.c
@@ -1054,10 +1054,23 @@ static int tegra_xusb_probe(struct platform_device *pdev)
 		}
 	}
 
+	tegra->hcd = usb_create_hcd(&tegra_xhci_hc_driver, &pdev->dev,
+				    dev_name(&pdev->dev));
+	if (!tegra->hcd) {
+		err = -ENOMEM;
+		goto put_padctl;
+	}
+
+	/*
+	 * This must happen after usb_create_hcd(), because usb_create_hcd()
+	 * will overwrite the drvdata of the device with the hcd it creates.
+	 */
+	platform_set_drvdata(pdev, tegra);
+
 	err = tegra_xusb_clk_enable(tegra);
 	if (err) {
 		dev_err(&pdev->dev, "failed to enable clocks: %d\n", err);
-		goto put_padctl;
+		goto put_usb2;
 	}
 
 	err = regulator_bulk_enable(tegra->soc->num_supplies, tegra->supplies);
@@ -1080,19 +1093,6 @@ static int tegra_xusb_probe(struct platform_device *pdev)
 		goto disable_phy;
 	}
 
-	tegra->hcd = usb_create_hcd(&tegra_xhci_hc_driver, &pdev->dev,
-				    dev_name(&pdev->dev));
-	if (!tegra->hcd) {
-		err = -ENOMEM;
-		goto disable_phy;
-	}
-
-	/*
-	 * This must happen after usb_create_hcd(), because usb_create_hcd()
-	 * will overwrite the drvdata of the device with the hcd it creates.
-	 */
-	platform_set_drvdata(pdev, tegra);
-
 	tegra->hcd->regs = tegra->regs;
 	tegra->hcd->rsrc_start = regs->start;
 	tegra->hcd->rsrc_len = resource_size(regs);
@@ -1100,7 +1100,7 @@ static int tegra_xusb_probe(struct platform_device *pdev)
 	err = usb_add_hcd(tegra->hcd, tegra->xhci_irq, IRQF_SHARED);
 	if (err < 0) {
 		dev_err(&pdev->dev, "failed to add USB HCD: %d\n", err);
-		goto put_usb2;
+		goto disable_phy;
 	}
 
 	device_wakeup_enable(tegra->hcd->self.controller);
@@ -1155,14 +1155,14 @@ static int tegra_xusb_probe(struct platform_device *pdev)
 	usb_put_hcd(xhci->shared_hcd);
 remove_usb2:
 	usb_remove_hcd(tegra->hcd);
-put_usb2:
-	usb_put_hcd(tegra->hcd);
 disable_phy:
 	tegra_xusb_phy_disable(tegra);
 disable_regulator:
 	regulator_bulk_disable(tegra->soc->num_supplies, tegra->supplies);
 disable_clk:
 	tegra_xusb_clk_disable(tegra);
+put_usb2:
+	usb_put_hcd(tegra->hcd);
 put_padctl:
 	tegra_xusb_padctl_put(tegra->padctl);
 	return err;
-- 
2.7.4