| Message ID | 20180417011742.192184-2-zhangjerry@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Felipe,
I noticed this wasn't queued up for 4.18. Do you think there is
anything I need to do to get this patch set into 4.19? Also, can we at
least add just this patch ('usb: gadget: f_fs: Only return delayed
status when len is 0') to 4.18 as functionfs control requests won't
work without it?
Thanks,
Jerry
On Mon, Apr 16, 2018 at 6:18 PM Jerry Zhang <zhangjerry@google.com> wrote:
>
> Commit 1b9ba000 ("Allow function drivers to pause control
> transfers") states that USB_GADGET_DELAYED_STATUS is only
> supported if data phase is 0 bytes.
>
> It seems that when the length is not 0 bytes, there is no
> need to explicitly delay the data stage since the transfer
> is not completed until the user responds. However, when the
> length is 0, there is no data stage and the transfer is
> finished once setup() returns, hence there is a need to
> explicitly delay completion.
>
> This manifests as the following bugs:
>
> Prior to 946ef68ad4e4 ('Let setup() return
> USB_GADGET_DELAYED_STATUS'), when setup is 0 bytes, ffs
> would require user to queue a 0 byte request in order to
> clear setup state. However, that 0 byte request was actually
> not needed and would hang and cause errors in other setup
> requests.
>
> After the above commit, 0 byte setups work since the gadget
> now accepts empty queues to ep0 to clear the delay, but all
> other setups hang.
>
> Fixes: 946ef68ad4e4 ("Let setup() return USB_GADGET_DELAYED_STATUS")
> Signed-off-by: Jerry Zhang <zhangjerry@google.com>
> ---
> drivers/usb/gadget/function/f_fs.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c
> index 7d5b1c448eb2..4b2cb9d93176 100644
> --- a/drivers/usb/gadget/function/f_fs.c
> +++ b/drivers/usb/gadget/function/f_fs.c
> @@ -3271,7 +3271,7 @@ static int ffs_func_setup(struct usb_function *f,
> __ffs_event_add(ffs, FUNCTIONFS_SETUP);
> spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
>
> - return USB_GADGET_DELAYED_STATUS;
> + return creq->wLength == 0 ? USB_GADGET_DELAYED_STATUS : 0;
> }
>
> static bool ffs_func_req_match(struct usb_function *f,
> --
> 2.17.0.484.g0c8726318c-goog
>
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Hi, Jerry Zhang <zhangjerry@google.com> writes: > Hi Felipe, > > I noticed this wasn't queued up for 4.18. Do you think there is > anything I need to do to get this patch set into 4.19? Also, can we at > least add just this patch ('usb: gadget: f_fs: Only return delayed > status when len is 0') to 4.18 as functionfs control requests won't > work without it? patch 1 is now queued for next merge window. What should I do with patches 2 and 3?
diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c index 7d5b1c448eb2..4b2cb9d93176 100644 --- a/drivers/usb/gadget/function/f_fs.c +++ b/drivers/usb/gadget/function/f_fs.c @@ -3271,7 +3271,7 @@ static int ffs_func_setup(struct usb_function *f, __ffs_event_add(ffs, FUNCTIONFS_SETUP); spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags); - return USB_GADGET_DELAYED_STATUS; + return creq->wLength == 0 ? USB_GADGET_DELAYED_STATUS : 0; } static bool ffs_func_req_match(struct usb_function *f,
Commit 1b9ba000 ("Allow function drivers to pause control transfers") states that USB_GADGET_DELAYED_STATUS is only supported if data phase is 0 bytes. It seems that when the length is not 0 bytes, there is no need to explicitly delay the data stage since the transfer is not completed until the user responds. However, when the length is 0, there is no data stage and the transfer is finished once setup() returns, hence there is a need to explicitly delay completion. This manifests as the following bugs: Prior to 946ef68ad4e4 ('Let setup() return USB_GADGET_DELAYED_STATUS'), when setup is 0 bytes, ffs would require user to queue a 0 byte request in order to clear setup state. However, that 0 byte request was actually not needed and would hang and cause errors in other setup requests. After the above commit, 0 byte setups work since the gadget now accepts empty queues to ep0 to clear the delay, but all other setups hang. Fixes: 946ef68ad4e4 ("Let setup() return USB_GADGET_DELAYED_STATUS") Signed-off-by: Jerry Zhang <zhangjerry@google.com> --- drivers/usb/gadget/function/f_fs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)