Re: [PATCH] USB: EHCI: ehci-mv: improve error handling in mv_ehci_enable()
From: Alan Stern
Date: Thu Jul 08 2021 - 09:40:12 EST
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 <novikov@xxxxxxxxx>
> ---
Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
> 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
>