From: Wesley Cheng <quic_wcheng@quicinc.com>
To: Takashi Iwai <tiwai@suse.de>, Oliver Neukum <oneukum@suse.com>
Cc: <srinivas.kandagatla@linaro.org>, <mathias.nyman@intel.com>,
<perex@perex.cz>, <broonie@kernel.org>, <lgirdwood@gmail.com>,
<andersson@kernel.org>, <krzysztof.kozlowski+dt@linaro.org>,
<gregkh@linuxfoundation.org>, <Thinh.Nguyen@synopsys.com>,
<bgoswami@quicinc.com>, <tiwai@suse.com>, <robh+dt@kernel.org>,
<agross@kernel.org>, <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: [RFC PATCH 04/14] sound: usb: card: Introduce USB SND vendor op callbacks
Date: Thu, 29 Dec 2022 23:10:36 -0800 [thread overview]
Message-ID: <ec632e64-2d9c-3f71-4fe7-e1c6acb81393@quicinc.com> (raw)
In-Reply-To: <87lemqxpet.wl-tiwai@suse.de>
Hi,
On 12/29/2022 6:20 AM, Takashi Iwai wrote:
> On Thu, 29 Dec 2022 14:49:21 +0100,
> Oliver Neukum wrote:
>>
>>
>>
>> On 24.12.22 00:31, Wesley Cheng wrote:
>>> Allow for different vendors to be notified on USB SND connect/disconnect
>>> seqeunces. This allows for vendor USB SND modules to properly initialize
>>> and populate internal structures with references to the USB SND chip
>>> device.
>>
>> Hi,
>>
>> this raises a design question. If the system is suspending or, worse,
>> hibernating, how do you make sure the offloader and the device are
>> suspended in the correct order?
>> And what happens if you need to go into reset_resume() when resuming?
It may depend on how the offloading is implemented, but we do have a
mechanism to force the audio stream off from the qc_usb_audio_offload.
Regardless of if the UDEV is suspended first, or the USB backend, as
long as we ensure that the offloading is disabled before entering
suspend, I think that should be sufficient. I would need to add some
suspend handling in the offload driver to issue the command to stop the
offloading.
As for the resume path, is there a concern if either device is resumed
first? The only scenario where maybe it could cause some mishandling is
if the USB backend is resumed before the offload driver is
connected/resumed. This means that the userspace ALSA would have access
to the platform sound card, and could potentially attempt to route audio
streams to it. I think in worst case, if we were going through a
reset_resume() we would end up rejecting that request coming from the
audio DSP to enable the stream. However, userspace entities would be
resumed/unfrozen last, so not sure if that would ever be a problem.
The reset_resume() path is fine. Bus reset is going to cause a
disconnect() callback in the offload driver, in which we already have
the proper handling for ensuring the offload path is halted, and we
reject any incoming stream start requests.
Thanks
Wesley Cheng
WARNING: multiple messages have this Message-ID (diff)
From: Wesley Cheng <quic_wcheng@quicinc.com>
To: Takashi Iwai <tiwai@suse.de>, Oliver Neukum <oneukum@suse.com>
Cc: linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org,
alsa-devel@alsa-project.org, linux-usb@vger.kernel.org,
bgoswami@quicinc.com, mathias.nyman@intel.com,
gregkh@linuxfoundation.org, andersson@kernel.org, tiwai@suse.com,
lgirdwood@gmail.com, robh+dt@kernel.org, broonie@kernel.org,
srinivas.kandagatla@linaro.org, agross@kernel.org,
krzysztof.kozlowski+dt@linaro.org, Thinh.Nguyen@synopsys.com,
quic_plai@quicinc.com, linux-kernel@vger.kernel.org,
quic_jackp@quicinc.com
Subject: Re: [RFC PATCH 04/14] sound: usb: card: Introduce USB SND vendor op callbacks
Date: Thu, 29 Dec 2022 23:10:36 -0800 [thread overview]
Message-ID: <ec632e64-2d9c-3f71-4fe7-e1c6acb81393@quicinc.com> (raw)
In-Reply-To: <87lemqxpet.wl-tiwai@suse.de>
Hi,
On 12/29/2022 6:20 AM, Takashi Iwai wrote:
> On Thu, 29 Dec 2022 14:49:21 +0100,
> Oliver Neukum wrote:
>>
>>
>>
>> On 24.12.22 00:31, Wesley Cheng wrote:
>>> Allow for different vendors to be notified on USB SND connect/disconnect
>>> seqeunces. This allows for vendor USB SND modules to properly initialize
>>> and populate internal structures with references to the USB SND chip
>>> device.
>>
>> Hi,
>>
>> this raises a design question. If the system is suspending or, worse,
>> hibernating, how do you make sure the offloader and the device are
>> suspended in the correct order?
>> And what happens if you need to go into reset_resume() when resuming?
It may depend on how the offloading is implemented, but we do have a
mechanism to force the audio stream off from the qc_usb_audio_offload.
Regardless of if the UDEV is suspended first, or the USB backend, as
long as we ensure that the offloading is disabled before entering
suspend, I think that should be sufficient. I would need to add some
suspend handling in the offload driver to issue the command to stop the
offloading.
As for the resume path, is there a concern if either device is resumed
first? The only scenario where maybe it could cause some mishandling is
if the USB backend is resumed before the offload driver is
connected/resumed. This means that the userspace ALSA would have access
to the platform sound card, and could potentially attempt to route audio
streams to it. I think in worst case, if we were going through a
reset_resume() we would end up rejecting that request coming from the
audio DSP to enable the stream. However, userspace entities would be
resumed/unfrozen last, so not sure if that would ever be a problem.
The reset_resume() path is fine. Bus reset is going to cause a
disconnect() callback in the offload driver, in which we already have
the proper handling for ensuring the offload path is halted, and we
reject any incoming stream start requests.
Thanks
Wesley Cheng
next prev parent reply other threads:[~2022-12-30 7:11 UTC|newest]
Thread overview: 171+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-23 23:31 [RFC PATCH 00/14] Introduce QC USB SND audio offloading support Wesley Cheng
2022-12-23 23:31 ` Wesley Cheng
2022-12-23 23:31 ` [RFC PATCH 01/14] ASoC: Add SOC USB APIs for adding an USB backend Wesley Cheng
2022-12-23 23:31 ` Wesley Cheng
2022-12-24 6:48 ` Greg KH
2022-12-24 6:48 ` Greg KH
2022-12-23 23:31 ` [RFC PATCH 02/14] ASoC: qcom: qdsp6: Introduce USB AFE port to q6dsp Wesley Cheng
2022-12-23 23:31 ` Wesley Cheng
2022-12-24 1:37 ` kernel test robot
2023-01-04 23:33 ` Pierre-Louis Bossart
2023-01-06 1:05 ` Wesley Cheng
2023-01-06 1:05 ` Wesley Cheng
2023-01-06 16:09 ` Pierre-Louis Bossart
2023-01-07 0:51 ` Wesley Cheng
2023-01-07 0:51 ` Wesley Cheng
2023-01-05 18:09 ` Krzysztof Kozlowski
2023-01-05 18:09 ` Krzysztof Kozlowski
2023-01-06 1:32 ` Wesley Cheng
2023-01-06 1:32 ` Wesley Cheng
2022-12-23 23:31 ` [RFC PATCH 03/14] ASoC: qcom: Add USB backend ASoC driver for Q6 Wesley Cheng
2022-12-23 23:31 ` Wesley Cheng
2022-12-24 2:17 ` kernel test robot
2022-12-24 2:17 ` kernel test robot
2022-12-24 9:02 ` Greg KH
2022-12-24 9:02 ` Greg KH
2022-12-27 13:04 ` Mark Brown
2022-12-27 13:04 ` Mark Brown
2022-12-27 13:45 ` Greg KH
2022-12-27 13:45 ` Greg KH
2022-12-27 14:02 ` Takashi Iwai
2022-12-27 14:02 ` Takashi Iwai
2022-12-27 14:11 ` Mark Brown
2022-12-27 14:11 ` Mark Brown
2022-12-27 15:11 ` Mark Brown
2022-12-27 15:11 ` Mark Brown
2022-12-27 21:06 ` Wesley Cheng
2022-12-27 21:06 ` Wesley Cheng
2022-12-27 21:07 ` Wesley Cheng
2022-12-27 21:07 ` Wesley Cheng
2023-01-04 23:41 ` Pierre-Louis Bossart
2023-01-06 1:05 ` Wesley Cheng
2023-01-06 1:05 ` Wesley Cheng
2023-01-06 16:16 ` Pierre-Louis Bossart
2022-12-23 23:31 ` [RFC PATCH 04/14] sound: usb: card: Introduce USB SND vendor op callbacks Wesley Cheng
2022-12-23 23:31 ` Wesley Cheng
2022-12-24 11:03 ` Dmitry Baryshkov
2022-12-24 11:03 ` Dmitry Baryshkov
2022-12-27 21:07 ` Wesley Cheng
2022-12-27 21:07 ` Wesley Cheng
2022-12-27 21:33 ` Dmitry Baryshkov
2022-12-27 21:33 ` Dmitry Baryshkov
2022-12-29 13:49 ` Oliver Neukum
2022-12-29 13:49 ` Oliver Neukum
2022-12-29 14:20 ` Takashi Iwai
2022-12-29 14:20 ` Takashi Iwai
2022-12-30 7:10 ` Wesley Cheng [this message]
2022-12-30 7:10 ` Wesley Cheng
2023-01-03 12:20 ` Oliver Neukum
2023-01-03 12:20 ` Oliver Neukum
2023-01-03 12:49 ` Takashi Iwai
2023-01-03 12:49 ` Takashi Iwai
2023-01-03 23:45 ` Wesley Cheng
2023-01-03 23:45 ` Wesley Cheng
2022-12-23 23:31 ` [RFC PATCH 05/14] sound: usb: Export USB SND APIs for modules Wesley Cheng
2022-12-23 23:31 ` Wesley Cheng
2022-12-24 6:48 ` Greg KH
2022-12-24 6:48 ` Greg KH
2022-12-23 23:31 ` [RFC PATCH 06/14] usb: core: hcd: Introduce USB HCD APIs for interrupter management Wesley Cheng
2022-12-23 23:31 ` Wesley Cheng
2022-12-24 8:54 ` Greg KH
2022-12-24 8:54 ` Greg KH
2022-12-27 21:13 ` Wesley Cheng
2022-12-27 21:13 ` Wesley Cheng
2022-12-24 15:29 ` Alan Stern
2022-12-24 15:29 ` Alan Stern
2022-12-27 21:07 ` Wesley Cheng
2022-12-27 21:07 ` Wesley Cheng
2022-12-28 8:59 ` Oliver Neukum
2022-12-28 8:59 ` Oliver Neukum
2022-12-28 15:16 ` Alan Stern
2022-12-28 15:16 ` Alan Stern
2022-12-28 20:31 ` Wesley Cheng
2022-12-28 20:31 ` Wesley Cheng
2022-12-29 1:41 ` Alan Stern
2022-12-29 1:41 ` Alan Stern
2022-12-23 23:31 ` [RFC PATCH 07/14] usb: host: xhci: Add XHCI secondary interrupter support Wesley Cheng
2022-12-23 23:31 ` Wesley Cheng
2022-12-24 5:59 ` kernel test robot
2022-12-24 8:55 ` Greg KH
2022-12-24 8:55 ` Greg KH
2022-12-28 15:47 ` Mathias Nyman
2022-12-28 15:47 ` Mathias Nyman
2022-12-29 21:14 ` Wesley Cheng
2022-12-29 21:14 ` Wesley Cheng
2023-01-02 16:38 ` Mathias Nyman
2023-01-02 16:38 ` Mathias Nyman
2023-01-09 20:24 ` Wesley Cheng
2023-01-09 20:24 ` Wesley Cheng
2023-01-10 19:47 ` Mathias Nyman
2023-01-10 19:47 ` Mathias Nyman
2023-01-10 20:03 ` Wesley Cheng
2023-01-10 20:03 ` Wesley Cheng
2023-01-11 3:11 ` Wesley Cheng
2023-01-11 3:11 ` Wesley Cheng
2023-01-12 9:24 ` Mathias Nyman
2023-01-12 9:24 ` Mathias Nyman
2023-01-13 0:34 ` Wesley Cheng
2023-01-13 0:34 ` Wesley Cheng
2022-12-23 23:31 ` [RFC PATCH 08/14] usb: dwc3: Add DT parameter to specify maximum number of interrupters Wesley Cheng
2022-12-23 23:31 ` Wesley Cheng
2022-12-24 11:13 ` Dmitry Baryshkov
2022-12-24 11:13 ` Dmitry Baryshkov
2022-12-26 12:28 ` Krzysztof Kozlowski
2022-12-26 12:28 ` Krzysztof Kozlowski
2022-12-27 21:06 ` Wesley Cheng
2022-12-27 21:06 ` Wesley Cheng
2022-12-23 23:31 ` [RFC PATCH 09/14] sound: usb: Introduce QC USB SND offloading support Wesley Cheng
2022-12-23 23:31 ` Wesley Cheng
2022-12-24 2:27 ` kernel test robot
2023-01-02 17:28 ` Takashi Iwai
2023-01-02 17:28 ` Takashi Iwai
2023-01-04 22:38 ` Wesley Cheng
2023-01-04 22:38 ` Wesley Cheng
2023-01-04 23:51 ` Pierre-Louis Bossart
2023-01-06 1:06 ` Wesley Cheng
2023-01-06 1:06 ` Wesley Cheng
2022-12-23 23:31 ` [RFC PATCH 10/14] sound: usb: card: Check for support for requested audio format Wesley Cheng
2022-12-23 23:31 ` Wesley Cheng
2022-12-24 8:59 ` Greg KH
2022-12-24 8:59 ` Greg KH
2022-12-27 21:07 ` Wesley Cheng
2022-12-27 21:07 ` Wesley Cheng
2022-12-27 20:31 ` kernel test robot
2022-12-23 23:31 ` [RFC PATCH 11/14] sound: soc: soc-usb: Add PCM format check API for USB backend Wesley Cheng
2022-12-23 23:31 ` Wesley Cheng
2022-12-24 2:17 ` kernel test robot
2022-12-24 2:17 ` kernel test robot
2022-12-23 23:31 ` [RFC PATCH 12/14] sound: soc: qcom: qusb6: Ensure PCM format is supported by USB audio device Wesley Cheng
2022-12-23 23:31 ` Wesley Cheng
2022-12-24 8:19 ` Sergey Shtylyov
2022-12-24 8:19 ` Sergey Shtylyov
2022-12-24 8:50 ` Wesley Cheng
2022-12-24 8:50 ` Wesley Cheng
2023-01-03 17:44 ` Mark Brown
2023-01-03 17:44 ` Mark Brown
2022-12-23 23:31 ` [RFC PATCH 13/14] ASoC: dt-bindings: Add Q6USB backend bindings Wesley Cheng
2022-12-23 23:31 ` Wesley Cheng
2022-12-26 12:25 ` Krzysztof Kozlowski
2022-12-26 12:25 ` Krzysztof Kozlowski
2022-12-23 23:32 ` [RFC PATCH 14/14] ASoC: dt-bindings: Update example for enabling USB offload on SM8250 Wesley Cheng
2022-12-23 23:32 ` Wesley Cheng
2022-12-26 12:27 ` Krzysztof Kozlowski
2022-12-26 12:27 ` Krzysztof Kozlowski
2023-01-03 17:46 ` Mark Brown
2023-01-03 17:46 ` Mark Brown
2023-01-05 18:09 ` Krzysztof Kozlowski
2023-01-05 18:09 ` Krzysztof Kozlowski
2023-01-04 0:46 ` Rob Herring
2023-01-04 0:46 ` Rob Herring
2022-12-24 6:45 ` [RFC PATCH 00/14] Introduce QC USB SND audio offloading support Greg KH
2022-12-24 6:45 ` Greg KH
2022-12-24 8:49 ` Wesley Cheng
2022-12-24 8:49 ` Wesley Cheng
2022-12-27 14:36 ` Mark Brown
2022-12-27 14:36 ` Mark Brown
2023-01-04 23:19 ` Pierre-Louis Bossart
2023-01-06 1:05 ` Wesley Cheng
2023-01-06 1:05 ` Wesley Cheng
2023-01-06 15:57 ` Pierre-Louis Bossart
2023-01-07 0:46 ` Wesley Cheng
2023-01-07 0:46 ` Wesley Cheng
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