On Fri, 22 Aug 2008 ajay.gupta@xxxxxx wrote:
> From: Ajay Kumar Gupta <ajay.gupta@xxxxxx>
>
> Fixes kernel panic while ISO IN transfer is aborted.Replaced usb_hcd_unlink_urb_from_ep() from musb_giveback() to __musb_giveback() to make sure urb is unlinked before giveback when __musb_giveback() is called from musb_urb_dequeue().
>
> Signed-off-by: Ajay Kumar Gupta <ajay.gupta@xxxxxx>
> ---
> drivers/usb/musb/musb_host.c | 3 +--
> 1 files changed, 1 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
> index 93b0678..a889ac4 100644
> --- a/drivers/usb/musb/musb_host.c
> +++ b/drivers/usb/musb/musb_host.c
> @@ -292,6 +292,7 @@ __acquires(musb->lock)
> );
>
> spin_unlock(&musb->lock);
> + usb_hcd_unlink_urb_from_ep(musb_to_hcd(musb), urb);
> usb_hcd_giveback_urb(musb_to_hcd(musb), urb, status);
> spin_lock(&musb->lock);
This is wrong. You must call usb_hcd_unlink_urb_from_ep() while
holding musb->lock.
You are correct. the unlink function should be moved above spin_unlock(). as,
+ usb_hcd_unlink_urb_from_ep(musb_to_hcd(musb), urb);
spin_unlock(&musb->lock);
usb_hcd_giveback_urb(musb_to_hcd(musb), urb, status);
spin_lock(&musb->lock);
Simiar locking issue is also in enqueue path where unlink is being done
without holding musb->lock.
Alan Stern--
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