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From: Arnaud POULIQUEN <arnaud.pouliquen@st.com>
To: Mathieu Poirier <mathieu.poirier@linaro.org>,
	Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Cc: "ohad@wizery.com" <ohad@wizery.com>,
	"bjorn.andersson@linaro.org" <bjorn.andersson@linaro.org>,
	"linux-remoteproc@vger.kernel.org"
	<linux-remoteproc@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v5 8/8] rpmsg: Turn name service into a stand alone driver
Date: Mon, 9 Nov 2020 09:48:37 +0100	[thread overview]
Message-ID: <e7dedfb6-1e9c-4246-9db1-e14a2e16c68c@st.com> (raw)
In-Reply-To: <20201106175332.GB3203364@xps15>

Hi Guennadi, Mathieu,

On 11/6/20 6:53 PM, Mathieu Poirier wrote:
> On Fri, Nov 06, 2020 at 03:00:28PM +0100, Guennadi Liakhovetski wrote:
>> On Fri, Nov 06, 2020 at 02:15:45PM +0100, Guennadi Liakhovetski wrote:
>>> Hi Mathieu, Arnaud,
>>>
>>> On Thu, Nov 05, 2020 at 03:50:28PM -0700, Mathieu Poirier wrote:
>>>> From: Arnaud Pouliquen <arnaud.pouliquen@st.com>
>>>>
>>>> Make the RPMSG name service announcement a stand alone driver so that it
>>>> can be reused by other subsystems.  It is also the first step in making the
>>>> functionatlity transport independent, i.e that is not tied to virtIO.
>>>
>>> Sorry, I just realised that my testing was incomplete. I haven't tested 
>>> automatic module loading and indeed it doesn't work. If rpmsg_ns is loaded 
>>> it probes and it's working, but if it isn't loaded and instead the rpmsg 
>>> bus driver is probed (e.g. virtio_rpmsg_bus), calling 
>>> rpmsg_ns_register_device() to create a new rpmsg_ns device doesn't cause 
>>> rpmsg_ns to be loaded.
>>
>> A simple fix for that is using MODULE_ALIAS("rpmsg:rpmsg_ns"); in rpmsg_ns.c 
>> but that alone doesn't fix the problem completely - the module does load then 
>> but not quickly enough, the NS announcement from the host / remote arrives 
>> before rpmsg_ns has properly registered. I think the best solution would be 
>> to link rpmsg_ns.c together with rpmsg_core.c. You'll probably want to keep 
>> the module name, so you could rename them to just core.c and ns.c.
> 
> I'm pretty sure it is because virtio_device_ready() in rpmsg_probe() is called
> before the kernel has finished loading the name space driver.  There has to be
> a way to prevent that from happening - I will investigate further.

Right, no dependency is set so the rpmsg_ns driver is never probed...
And  name service announcement messages are dropped if the service is not present.

if rpmsg_virtio_bus is built-in
-> using "select RPMSG_NS" in RPMSG_VIRTIO kconfig should ensure that rpmsg_ns is also built-in 
if rpmsg_virtio_bus is build as module rpmsg_ns.ko should be loaded first.
-> MODULE_SOFTDEP could be used in virtio_rpmsg_bus.c

Thanks,
Arnaud

> 
> Thanks for reporting this,
> Mathieu
> 
>>
>> Thanks
>> Guennadi

  reply	other threads:[~2020-11-09  8:49 UTC|newest]

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-05 22:50 [PATCH v5 0/8] rpmsg: Make RPMSG name service modular Mathieu Poirier
2020-11-05 22:50 ` [PATCH v5 1/8] rpmsg: Introduce __rpmsg{16|32|64} types Mathieu Poirier
2020-11-05 22:50 ` [PATCH v5 2/8] rpmsg: virtio: Move from virtio to rpmsg byte conversion Mathieu Poirier
2020-11-05 22:50 ` [PATCH v5 3/8] rpmsg: Move structure rpmsg_ns_msg to header file Mathieu Poirier
2020-11-05 22:50 ` [PATCH v5 4/8] rpmsg: virtio: Rename rpmsg_create_channel Mathieu Poirier
2020-11-05 22:50 ` [PATCH v5 5/8] rpmsg: core: Add channel creation internal API Mathieu Poirier
2020-11-05 22:50 ` [PATCH v5 6/8] rpmsg: virtio: Add rpmsg channel device ops Mathieu Poirier
2020-11-05 22:50 ` [PATCH v5 7/8] rpmsg: Make rpmsg_{register|unregister}_device() public Mathieu Poirier
2020-11-05 22:50 ` [PATCH v5 8/8] rpmsg: Turn name service into a stand alone driver Mathieu Poirier
2020-11-06 13:15   ` Guennadi Liakhovetski
2020-11-06 14:00     ` Guennadi Liakhovetski
2020-11-06 17:53       ` Mathieu Poirier
2020-11-09  8:48         ` Arnaud POULIQUEN [this message]
2020-11-09 10:20           ` Guennadi Liakhovetski
2020-11-09 17:55             ` Mathieu Poirier
2020-11-10 18:18               ` Arnaud POULIQUEN
2020-11-11  0:37                 ` Mathieu Poirier
2020-11-12  9:04                   ` Arnaud POULIQUEN
2020-11-14 17:51                     ` Mathieu Poirier
2020-11-11 14:49                 ` Guennadi Liakhovetski
2020-11-12 10:17                   ` Arnaud POULIQUEN
2020-11-12 11:51                     ` Guennadi Liakhovetski
2020-11-12 13:27                       ` Arnaud POULIQUEN
2020-11-16 14:43                         ` Arnaud POULIQUEN
2020-11-16 15:10                           ` Guennadi Liakhovetski
2020-11-16 15:51                             ` Arnaud POULIQUEN
2020-11-16 16:20                               ` Guennadi Liakhovetski
2020-11-16 22:40                               ` Mathieu Poirier
2020-11-17  6:45                                 ` Guennadi Liakhovetski
2020-11-17 11:42                                 ` Arnaud POULIQUEN
2020-11-17 16:03                                   ` Guennadi Liakhovetski
2020-11-17 16:44                                     ` Arnaud POULIQUEN
2020-11-17 16:58                                       ` Guennadi Liakhovetski
2020-11-17 17:30                                         ` Arnaud POULIQUEN
2020-11-17 20:40                                           ` Guennadi Liakhovetski
2020-11-18  0:06                                       ` Mathieu Poirier
2020-11-18  7:08                                         ` Guennadi Liakhovetski
2020-11-18 16:16                                           ` Mathieu Poirier

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