Hi,
Thinh Nguyen <thinh.nguyen@xxxxxxxxxxxx> writes:
> Hi Felipe,
>
> On 11/7/2018 11:03 PM, Felipe Balbi wrote:
>> Hi,
>>
>> Thinh Nguyen <thinh.nguyen@xxxxxxxxxxxx> writes:
>>> Similar to URB's start_frame, add a field start_frame to the usb_request
>>> to report the scheduled (micro)frame number of an isochronous transfer.
>>> This option is useful for debugging purposes.
>>>
>>> Signed-off-by: Thinh Nguyen <thinhn@xxxxxxxxxxxx>
>>> ---
>>> include/linux/usb/gadget.h | 3 +++
>>> 1 file changed, 3 insertions(+)
>>>
>>> diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
>>> index e5cd84a0f84a..ed9dbbce55ee 100644
>>> --- a/include/linux/usb/gadget.h
>>> +++ b/include/linux/usb/gadget.h
>>> @@ -50,6 +50,7 @@ struct usb_ep;
>>> * @short_not_ok: When reading data, makes short packets be
>>> * treated as errors (queue stops advancing till cleanup).
>>> * @dma_mapped: Indicates if request has been mapped to DMA (internal)
>>> + * @start_frame: the reported (micro)frame of the scheduled isoc transfer
>>> * @complete: Function called when request completes, so this request and
>>> * its buffer may be re-used. The function will always be called with
>>> * interrupts disabled, and it must not sleep.
>>> @@ -107,6 +108,8 @@ struct usb_request {
>>> unsigned short_not_ok:1;
>>> unsigned dma_mapped:1;
>>>
>>> + int start_frame; /* ISO ONLY */
>> this name is a bit misleading. I can see functions trying to use it to
>> request that a particular request start on a specific frame. Would
>> "started_frame" be a better name, perhaps?
>
> What do you think of changing this field name to "frame_number"? It's
> generic enough so that this field can potentially be updated in the
> future to be used as a starting frame in the future, for synchronization.
I don't mind, but remember changing semantics will mean auditing every
user of this :-)
--
balbi
