Le 02/03/2024 à 17:35, Anand Moon a écrit :
Hi Christophe,
On Sat, 2 Mar 2024 at 21:19, Christophe JAILLET
<christophe.jaillet@xxxxxxxxxx> wrote:
Le 01/03/2024 à 20:38, Anand Moon a écrit :
The devm_clk_get_enabled() helpers:
- call devm_clk_get()
- call clk_prepare_enable() and register what is needed in order to
call clk_disable_unprepare() when needed, as a managed resource.
This simplifies the code and avoids the calls to clk_disable_unprepare().
While at it, use dev_err_probe consistently, and use its return value
to return the error code.
Signed-off-by: Anand Moon <linux.amoon@xxxxxxxxx>
---
drivers/usb/host/ehci-exynos.c | 30 +++++-------------------------
1 file changed, 5 insertions(+), 25 deletions(-)
diff --git a/drivers/usb/host/ehci-exynos.c b/drivers/usb/host/ehci-exynos.c
index f644b131cc0b..05aa3d9c2a3b 100644
--- a/drivers/usb/host/ehci-exynos.c
+++ b/drivers/usb/host/ehci-exynos.c
@@ -159,19 +159,12 @@ static int exynos_ehci_probe(struct platform_device *pdev)
err = exynos_ehci_get_phy(&pdev->dev, exynos_ehci);
if (err)
- goto fail_clk;
-
- exynos_ehci->clk = devm_clk_get(&pdev->dev, "usbhost");
-
- if (IS_ERR(exynos_ehci->clk)) {
- dev_err(&pdev->dev, "Failed to get usbhost clock\n");
- err = PTR_ERR(exynos_ehci->clk);
- goto fail_clk;
- }
+ goto fail_io;
- err = clk_prepare_enable(exynos_ehci->clk);
- if (err)
- goto fail_clk;
+ exynos_ehci->clk = devm_clk_get_enabled(&pdev->dev, "usbhost");
+ if (IS_ERR(exynos_ehci->clk))
+ return dev_err_probe(&pdev->dev, PTR_ERR(exynos_ehci->clk),
+ "Failed to get usbhost clock\n");
hcd->regs = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
if (IS_ERR(hcd->regs)) {
@@ -223,8 +216,6 @@ static int exynos_ehci_probe(struct platform_device *pdev)
exynos_ehci_phy_disable(&pdev->dev);
pdev->dev.of_node = exynos_ehci->of_node;
fail_io:
- clk_disable_unprepare(exynos_ehci->clk);
-fail_clk:
usb_put_hcd(hcd);
return err;
}
@@ -240,8 +231,6 @@ static void exynos_ehci_remove(struct platform_device *pdev)
exynos_ehci_phy_disable(&pdev->dev);
- clk_disable_unprepare(exynos_ehci->clk);
-
usb_put_hcd(hcd);
}
@@ -249,7 +238,6 @@ static void exynos_ehci_remove(struct platform_device *pdev)
static int exynos_ehci_suspend(struct device *dev)
{
struct usb_hcd *hcd = dev_get_drvdata(dev);
- struct exynos_ehci_hcd *exynos_ehci = to_exynos_ehci(hcd);
bool do_wakeup = device_may_wakeup(dev);
int rc;
@@ -260,25 +248,17 @@ static int exynos_ehci_suspend(struct device *dev)
exynos_ehci_phy_disable(dev);
- clk_disable_unprepare(exynos_ehci->clk);
Hi,
I don't think that removing clk_[en|dis]abble from the suspend and
resume function is correct.
The goal is to stop some hardware when the system is suspended, in order
to save some power.
Yes correct,
Why did you removed it?
devm_clk_get_enabled function register callback for clk_prepare_enable
and clk_disable_unprepare, so when the clock resource is not used it should get
disabled.
Same explanation as in the other patch.
The registered function is called when the driver is *unloaded*, not
when it magically knows that some things can be disabled or enabled.
CJ
[0] https://elixir.bootlin.com/linux/latest/source/drivers/clk/clk-devres.c#L75
I have also tested with rtc suspend & resume and did not find any issue.
CJ
Thanks
-Anand
-
return rc;
}
static int exynos_ehci_resume(struct device *dev)
{
struct usb_hcd *hcd = dev_get_drvdata(dev);
- struct exynos_ehci_hcd *exynos_ehci = to_exynos_ehci(hcd);
int ret;
- ret = clk_prepare_enable(exynos_ehci->clk);
- if (ret)
- return ret;
-
ret = exynos_ehci_phy_enable(dev);
if (ret) {
dev_err(dev, "Failed to enable USB phy\n");
- clk_disable_unprepare(exynos_ehci->clk);
return ret;
}
