[PATCH v3 2/6] usb: host: xhci-plat: get optional clock by devm_clk_get_optional()

From: Chunfeng Yun
Date: Wed Apr 17 2019 - 04:28:38 EST


When the driver tries to get optional clock, it ignores all errors except
-EPROBE_DEFER, but if only ignores -ENOENT, it will cover some real errors,
such as -ENOMEM, so use devm_clk_get_optional() to get optional clock.

Cc: Mathias Nyman <mathias.nyman@xxxxxxxxx>
Signed-off-by: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx>
---
v3: modify changelog comment
v2: no changes
---
drivers/usb/host/xhci-plat.c | 39 +++++++++++++++++-------------------
1 file changed, 18 insertions(+), 21 deletions(-)

diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
index 0ac4ec975547..998241f5fce3 100644
--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c
@@ -165,8 +165,6 @@ static int xhci_plat_probe(struct platform_device *pdev)
struct xhci_hcd *xhci;
struct resource *res;
struct usb_hcd *hcd;
- struct clk *clk;
- struct clk *reg_clk;
int ret;
int irq;

@@ -235,31 +233,32 @@ static int xhci_plat_probe(struct platform_device *pdev)
hcd->rsrc_start = res->start;
hcd->rsrc_len = resource_size(res);

+ xhci = hcd_to_xhci(hcd);
+
/*
* Not all platforms have clks so it is not an error if the
* clock do not exist.
*/
- reg_clk = devm_clk_get(&pdev->dev, "reg");
- if (!IS_ERR(reg_clk)) {
- ret = clk_prepare_enable(reg_clk);
- if (ret)
- goto put_hcd;
- } else if (PTR_ERR(reg_clk) == -EPROBE_DEFER) {
- ret = -EPROBE_DEFER;
+ xhci->reg_clk = devm_clk_get_optional(&pdev->dev, "reg");
+ if (IS_ERR(xhci->reg_clk)) {
+ ret = PTR_ERR(xhci->reg_clk);
goto put_hcd;
}

- clk = devm_clk_get(&pdev->dev, NULL);
- if (!IS_ERR(clk)) {
- ret = clk_prepare_enable(clk);
- if (ret)
- goto disable_reg_clk;
- } else if (PTR_ERR(clk) == -EPROBE_DEFER) {
- ret = -EPROBE_DEFER;
+ ret = clk_prepare_enable(xhci->reg_clk);
+ if (ret)
+ goto put_hcd;
+
+ xhci->clk = devm_clk_get_optional(&pdev->dev, NULL);
+ if (IS_ERR(xhci->clk)) {
+ ret = PTR_ERR(xhci->clk);
goto disable_reg_clk;
}

- xhci = hcd_to_xhci(hcd);
+ ret = clk_prepare_enable(xhci->clk);
+ if (ret)
+ goto disable_reg_clk;
+
priv_match = of_device_get_match_data(&pdev->dev);
if (priv_match) {
struct xhci_plat_priv *priv = hcd_to_xhci_priv(hcd);
@@ -271,8 +270,6 @@ static int xhci_plat_probe(struct platform_device *pdev)

device_wakeup_enable(hcd->self.controller);

- xhci->clk = clk;
- xhci->reg_clk = reg_clk;
xhci->main_hcd = hcd;
xhci->shared_hcd = __usb_create_hcd(driver, sysdev, &pdev->dev,
dev_name(&pdev->dev), hcd);
@@ -348,10 +345,10 @@ static int xhci_plat_probe(struct platform_device *pdev)
usb_put_hcd(xhci->shared_hcd);

disable_clk:
- clk_disable_unprepare(clk);
+ clk_disable_unprepare(xhci->clk);

disable_reg_clk:
- clk_disable_unprepare(reg_clk);
+ clk_disable_unprepare(xhci->reg_clk);

put_hcd:
usb_put_hcd(hcd);
--
2.21.0