On Thu, Dec 05, 2024 at 04:33:00PM +0300, Vitalii Mordan wrote:
> If the clock sohci_p->clk was not enabled in spear_ohci_hcd_drv_probe,
> it should not be disabled in any path.
>
> Conversely, if it was enabled in spear_ohci_hcd_drv_probe, it must be disabled
> in all error paths to ensure proper cleanup.
>
> The check inside spear_ohci_hcd_drv_resume() actually doesn't prevent
> the clock to be unconditionally disabled later during the driver removal but
> it is still good to have the check at least so that the PM core would duly
> print the errors in the system log. This would also be consistent with
> the similar code paths in ->resume() functions of other usb drivers, e.g. in
> exynos_ehci_resume().
>
> Found by Linux Verification Center (linuxtesting.org) with Klever.
>
> Fixes: 1cc6ac59ffaa ("USB: OHCI: make ohci-spear a separate driver")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Vitalii Mordan <mordan@xxxxxxxxx>
> ---
Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
> drivers/usb/host/ohci-spear.c | 12 ++++++++----
> 1 file changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/usb/host/ohci-spear.c b/drivers/usb/host/ohci-spear.c
> index 993f347c5c28..6f6ae6fadfe5 100644
> --- a/drivers/usb/host/ohci-spear.c
> +++ b/drivers/usb/host/ohci-spear.c
> @@ -80,7 +80,9 @@ static int spear_ohci_hcd_drv_probe(struct platform_device *pdev)
> sohci_p = to_spear_ohci(hcd);
> sohci_p->clk = usbh_clk;
>
> - clk_prepare_enable(sohci_p->clk);
> + retval = clk_prepare_enable(sohci_p->clk);
> + if (retval)
> + goto err_put_hcd;
>
> retval = usb_add_hcd(hcd, irq, 0);
> if (retval == 0) {
> @@ -103,8 +105,7 @@ static void spear_ohci_hcd_drv_remove(struct platform_device *pdev)
> struct spear_ohci *sohci_p = to_spear_ohci(hcd);
>
> usb_remove_hcd(hcd);
> - if (sohci_p->clk)
> - clk_disable_unprepare(sohci_p->clk);
> + clk_disable_unprepare(sohci_p->clk);
>
> usb_put_hcd(hcd);
> }
> @@ -137,12 +138,15 @@ static int spear_ohci_hcd_drv_resume(struct platform_device *dev)
> struct usb_hcd *hcd = platform_get_drvdata(dev);
> struct ohci_hcd *ohci = hcd_to_ohci(hcd);
> struct spear_ohci *sohci_p = to_spear_ohci(hcd);
> + int ret;
>
> if (time_before(jiffies, ohci->next_statechange))
> msleep(5);
> ohci->next_statechange = jiffies;
>
> - clk_prepare_enable(sohci_p->clk);
> + ret = clk_prepare_enable(sohci_p->clk);
> + if (ret)
> + return ret;
> ohci_resume(hcd, false);
> return 0;
> }
> --
> 2.25.1
>
