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

From: Wesley Cheng <quic_wcheng@quicinc.com>
To: Mathias Nyman <mathias.nyman@linux.intel.com>,
	<srinivas.kandagatla@linaro.org>, <mathias.nyman@intel.com>,
	<perex@perex.cz>, <broonie@kernel.org>, <lgirdwood@gmail.com>,
	<krzysztof.kozlowski+dt@linaro.org>, <agross@kernel.org>,
	<Thinh.Nguyen@synopsys.com>, <bgoswami@quicinc.com>,
	<andersson@kernel.org>, <robh+dt@kernel.org>,
	<gregkh@linuxfoundation.org>, <tiwai@suse.com>
Cc: linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org,
	alsa-devel@alsa-project.org, devicetree@vger.kernel.org,
	linux-usb@vger.kernel.org, quic_jackp@quicinc.com,
	quic_plai@quicinc.com
Subject: Re: [PATCH v3 01/28] xhci: Add support to allocate several interrupters
Date: Mon, 13 Mar 2023 13:32:27 -0700	[thread overview]
Message-ID: <ed0397eb-da17-fbee-647e-f3a2a57577fe@quicinc.com> (raw)
In-Reply-To: <a45ff335-0563-85c7-3b31-d6ca23a54a3f@linux.intel.com>

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.

Thanks
Wesley Cheng