2021-07-08 08:32:18

by Evgeny Novikov

Subject: [PATCH] USB: EHCI: ehci-mv: improve error handling in mv_ehci_enable()

mv_ehci_enable() did not disable and unprepare clocks in case of
failures of phy_init(). Besides, it did not take into account failures
of ehci_clock_enable() (in effect, failures of clk_prepare_enable()).
The patch fixes both issues and gets rid of redundant wrappers around
clk_prepare_enable() and clk_disable_unprepare() to simplify this a bit.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Evgeny Novikov <[email protected]>
---
drivers/usb/host/ehci-mv.c | 23 +++++++++++------------
1 file changed, 11 insertions(+), 12 deletions(-)

diff --git a/drivers/usb/host/ehci-mv.c b/drivers/usb/host/ehci-mv.c
index cffdc8d01b2a..8fd27249ad25 100644
--- a/drivers/usb/host/ehci-mv.c
+++ b/drivers/usb/host/ehci-mv.c
@@ -42,26 +42,25 @@ struct ehci_hcd_mv {
int (*set_vbus)(unsigned int vbus);
};

-static void ehci_clock_enable(struct ehci_hcd_mv *ehci_mv)
+static int mv_ehci_enable(struct ehci_hcd_mv *ehci_mv)
{
- clk_prepare_enable(ehci_mv->clk);
-}
+ int retval;

-static void ehci_clock_disable(struct ehci_hcd_mv *ehci_mv)
-{
- clk_disable_unprepare(ehci_mv->clk);
-}
+ retval = clk_prepare_enable(ehci_mv->clk);
+ if (retval)
+ return retval;

-static int mv_ehci_enable(struct ehci_hcd_mv *ehci_mv)
-{
- ehci_clock_enable(ehci_mv);
- return phy_init(ehci_mv->phy);
+ retval = phy_init(ehci_mv->phy);
+ if (retval)
+ clk_disable_unprepare(ehci_mv->clk);
+
+ return retval;
}

static void mv_ehci_disable(struct ehci_hcd_mv *ehci_mv)
{
phy_exit(ehci_mv->phy);
- ehci_clock_disable(ehci_mv);
+ clk_disable_unprepare(ehci_mv->clk);
}

static int mv_ehci_reset(struct usb_hcd *hcd)
--
2.26.2

2021-07-08 13:44:15

by Alan Stern

Subject: Re: [PATCH] USB: EHCI: ehci-mv: improve error handling in mv_ehci_enable()

On Thu, Jul 08, 2021 at 11:30:56AM +0300, Evgeny Novikov wrote:
> mv_ehci_enable() did not disable and unprepare clocks in case of
> failures of phy_init(). Besides, it did not take into account failures
> of ehci_clock_enable() (in effect, failures of clk_prepare_enable()).
> The patch fixes both issues and gets rid of redundant wrappers around
> clk_prepare_enable() and clk_disable_unprepare() to simplify this a bit.
>
> Found by Linux Driver Verification project (linuxtesting.org).
>
> Signed-off-by: Evgeny Novikov <[email protected]>
> ---

Acked-by: Alan Stern <[email protected]>

> drivers/usb/host/ehci-mv.c | 23 +++++++++++------------
> 1 file changed, 11 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/usb/host/ehci-mv.c b/drivers/usb/host/ehci-mv.c
> index cffdc8d01b2a..8fd27249ad25 100644
> --- a/drivers/usb/host/ehci-mv.c
> +++ b/drivers/usb/host/ehci-mv.c
> @@ -42,26 +42,25 @@ struct ehci_hcd_mv {
> int (*set_vbus)(unsigned int vbus);
> };
>
> -static void ehci_clock_enable(struct ehci_hcd_mv *ehci_mv)
> +static int mv_ehci_enable(struct ehci_hcd_mv *ehci_mv)
> {
> - clk_prepare_enable(ehci_mv->clk);
> -}
> + int retval;
>
> -static void ehci_clock_disable(struct ehci_hcd_mv *ehci_mv)
> -{
> - clk_disable_unprepare(ehci_mv->clk);
> -}
> + retval = clk_prepare_enable(ehci_mv->clk);
> + if (retval)
> + return retval;
>
> -static int mv_ehci_enable(struct ehci_hcd_mv *ehci_mv)
> -{
> - ehci_clock_enable(ehci_mv);
> - return phy_init(ehci_mv->phy);
> + retval = phy_init(ehci_mv->phy);
> + if (retval)
> + clk_disable_unprepare(ehci_mv->clk);
> +
> + return retval;
> }
>
> static void mv_ehci_disable(struct ehci_hcd_mv *ehci_mv)
> {
> phy_exit(ehci_mv->phy);
> - ehci_clock_disable(ehci_mv);
> + clk_disable_unprepare(ehci_mv->clk);
> }
>
> static int mv_ehci_reset(struct usb_hcd *hcd)
> --
> 2.26.2
>