Re: [PATCH v3 01/28] xhci: Add support to allocate several interrupters

[Wesley Cheng <quic_wcheng@quicinc.com>]

Hi Mathias,

On 6/26/2023 6:55 AM, Mathias Nyman wrote:
> On 24.6.2023 1.37, Wesley Cheng wrote:
>> Hi Mathias,
>>
>> On 3/13/2023 1:32 PM, Wesley Cheng wrote:
>>> Hi Mathias,
>>>
>>> On 3/10/2023 7:07 AM, Mathias Nyman wrote:
>>>> On 9.3.2023 1.57, Wesley Cheng wrote:
>>>>> From: Mathias Nyman <mathias.nyman@linux.intel.com>
>>>>>
>>>>> Introduce xHCI APIs to allow for clients to allocate and free
>>>>> interrupters.  This allocates an array of interrupters, which is 
>>>>> based on
>>>>> the max_interrupters parameter.  The primary interrupter is set as the
>>>>> first entry in the array, and secondary interrupters following after.
>>>>>
>>>>
>>>> I'm thinking about changing this offloading xHCI API
>>>> xhci should be aware and keep track of which devices and endpoints that
>>>> are offloaded to avoid device getting offloaded twice, avoid xhci 
>>>> driver
>>>> from queuing anything itself for these, and act properly if the 
>>>> offloaded
>>>> device or entire host is removed.
>>>>
>>>> So first thing audio side would need to do do is register/create an
>>>> offload entry for the device using the API:
>>>>
>>>> struct xhci_sideband *xhci_sideband_register(struct usb_device *udev)
>>>>
>>>> (xHCI specs calls offload sideband)
>>>> Then endpoints and interrupters can be added and removed from this
>>>> offload entry
>>>>
>>>> I have some early thoughts written as non-compiling code in:
>>>>
>>>> git://git.kernel.org/pub/scm/linux/kernel/git/mnyman/xhci.git 
>>>> feature_interrupters
>>>> https://git.kernel.org/pub/scm/linux/kernel/git/mnyman/xhci.git/log/?h=feature_interrupters 
>>>>
>>>>
>>>> Let me know what you think about this.
>>>>
>>>>> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
>>>>> Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
>>>>
>>>> My Signed-off-by tag is being misused here.
>>>>
>>>> I wrote a chunk of the code in this patch as PoC that I shared in a 
>>>> separate topic branch.
>>>> It was incomplete and not intended for upstream yet. (lacked 
>>>> locking, several fixme parts, etc..)
>>>> The rest of the code in this patch is completely new to me.
>>>>
>>>
>>> Sorry about this.  I cherry picked the change directly from your 
>>> branch, so it carried your signed off tag with it.  Will make to 
>>> include them properly next time.
>>>
>>
>> I'm about ready to submit the next revision for this set of changes, 
>> and I was wondering how we should handle the changes you made on:
>> https://git.kernel.org/pub/scm/linux/kernel/git/mnyman/xhci.git/log/?h=feature_interrupters 
>>
>>
>> I did make some modifications to some of the interrupter fixme tags 
>> you had, and also updated the xhci-sideband APIs with the proper 
>> logic.  I don't believe it is correct for me to submit a set of 
>> patches authored by you without your signed off tag. (checkpatch 
>> throws an error saying the author did not sign off on the change)
>>
> 
> Note that the first patch "xhci: split allocate interrupter into 
> separate alloacte and add parts"
> is already in usb-next on its way to 6.5
> 
> Maybe Co-developed-by would work in this case, with a small explanation 
> at the end of the commit message.
> Something like:
> 
> Locking, DMA something and feataure x added by Wesley Cheng to
> complete original concept code by Mathias
> 
> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
> Co-developed-by: Wesley Cheng <quic_wcheng@quicinc.com>
> Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
> 

Sounds good!  Thanks for helping with a non-technical question :).  Just 
wanted to make sure I wasn't overstepping anywhere.

Thanks
Wesley Cheng