Re: [PATCH] usb: isp1760: fix spin unlock in the error path of isp1760_udc_start

From: Laurent Pinchart
Date: Fri Mar 20 2015 - 10:20:25 EST


Hi Sudeep,

Thank you for the patch.

On Friday 20 March 2015 11:42:17 Sudeep Holla wrote:
> Commit a124820de5fd ("usb: isp1760: fix possible deadlock in
> isp1760_udc_irq") replaced spin_{un,}lock with
> spin_{un,}lock_irq{save,restore}. However it missed an error path resulting
> in the smatch warning as below:
>
> drivers/usb/isp1760/isp1760-udc.c:1230 isp1760_udc_start() warn:
> inconsistent returns 'irqsave:flags'. Locked on: line 1207
> Unlocked on: line 1199
>
> This patch fixes the spin unlock in the error path in isp1760_udc_start
> thereby removing the smatch warning mentioned above.
>
> Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> Cc: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> Cc: Felipe Balbi <balbi@xxxxxx>
> Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxx>

Acked-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>

> ---
> drivers/usb/isp1760/isp1760-udc.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> Hi Laurent, Felipe,
>
> I am extremely sorry for missing this in my original patch.

I hope you will be ashamed for the 7 generations to come for this totally
unacceptable low quality standard.

Just kidding of course, to err is human :-) Thank you for fixing it.

> Thanks to Dan Carpenter for reporting this.
>
> Regards,
> Sudeep
>
> diff --git a/drivers/usb/isp1760/isp1760-udc.c
> b/drivers/usb/isp1760/isp1760-udc.c index fbfbd59aae64..b7094eee0bdd 100644
> --- a/drivers/usb/isp1760/isp1760-udc.c
> +++ b/drivers/usb/isp1760/isp1760-udc.c
> @@ -1203,7 +1203,7 @@ static int isp1760_udc_start(struct usb_gadget
> *gadget,
>
> if (udc->driver) {
> dev_err(udc->isp->dev, "UDC already has a gadget driver\n");
> - spin_unlock(&udc->lock);
> + spin_unlock_irqrestore(&udc->lock, flags);
> return -EBUSY;
> }

--
Regards,

Laurent Pinchart

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