From: Arnaud POULIQUEN <arnaud.pouliquen@foss.st.com>
To: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Ohad Ben-Cohen <ohad@wizery.com>,
Mathieu Poirier <mathieu.poirier@linaro.org>,
<linux-remoteproc@vger.kernel.org>,
<linux-kernel@vger.kernel.org>,
<linux-stm32@st-md-mailman.stormreply.com>
Subject: Re: [PATCH v5 3/4] rpmsg: Move the rpmsg control device from rpmsg_char to rpmsg_ctrl
Date: Mon, 18 Oct 2021 11:13:04 +0200 [thread overview]
Message-ID: <ffb110dc-bc3b-dbc2-679f-de2416f7b90f@foss.st.com> (raw)
In-Reply-To: <YWpZMwgWqcPMvL5q@yoga>
On 10/16/21 6:46 AM, Bjorn Andersson wrote:
> On Mon 11 Oct 05:46 CDT 2021, Arnaud POULIQUEN wrote:
>
>>
>>
>> On 10/9/21 1:35 AM, Bjorn Andersson wrote:
>>> On Mon 12 Jul 05:37 PDT 2021, Arnaud Pouliquen wrote:
>>>
>>>> Create the rpmsg_ctrl.c module and move the code related to the
>>>> rpmsg_ctrldev device in this new module.
>>>>
>>>> Add the dependency between rpmsg_char and rpmsg_ctrl in the
>>>> kconfig file.
>>>>
>>>
>>> As I said in the cover letter, the only reason I can see for doing this
>>> refactoring is in relation to the introduction of
>>> RPMSG_CREATE_DEV_IOCTL. So I would like this patch to go together with
>>> that patch, together with a good motivation why there's merit to
>>> creating yet another kernel module (and by bind/unbind can't be used).
>>>
>>> Perhaps I'm just missing some good usecase related to this?
>>
>>
>>>
>>>> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>
>>>> Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
>>>> ---
>>>> drivers/rpmsg/Kconfig | 9 ++
>>>> drivers/rpmsg/Makefile | 1 +
>>>> drivers/rpmsg/rpmsg_char.c | 170 +----------------------------
>>>> drivers/rpmsg/rpmsg_char.h | 2 +
>>>> drivers/rpmsg/rpmsg_ctrl.c | 215 +++++++++++++++++++++++++++++++++++++
>>>> 5 files changed, 229 insertions(+), 168 deletions(-)
>>>> create mode 100644 drivers/rpmsg/rpmsg_ctrl.c
>>>>
>>> [..]
>>>> diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c
>>> [..]
>>>> -static int rpmsg_chrdev_probe(struct rpmsg_device *rpdev)
>>>> -{
>>> [..]
>>>> - dev = &ctrldev->dev;
>>>> - device_initialize(dev);
>>>> - dev->parent = &rpdev->dev;
>>>> - dev->class = rpmsg_class;
>>> [..]
>>>> diff --git a/drivers/rpmsg/rpmsg_ctrl.c b/drivers/rpmsg/rpmsg_ctrl.c
>>> [..]
>>>> +static int rpmsg_ctrldev_probe(struct rpmsg_device *rpdev)
>>>> +{
>>> [..]
>>>> + dev = &ctrldev->dev;
>>>> + device_initialize(dev);
>>>> + dev->parent = &rpdev->dev;
>>>
>>> You lost the assignment of dev->class here, which breaks the udev rules
>>> we use to invoke rpmsgexport to create endpoints and it causes udevadm
>>> to complain that rpmsg_ctrlN doesn't have a "subsystem".
>>
>> We discussed this point with Mathieu, as a first step i kept the class, but that
>> generated another dependency with the rpmsg_char device while information was
>> available on the rpmsg bus. The char device and ctrl device should share the
>> same class. As rpmsg_ctrl is created first it would have to create the class,and
>> provide an API to rpmsg char
>>
>
> Perhaps if this is considered a common piece shared between multiple
> rpmsg modules we can create such class in the rpmsg "core" itself?
Yes that seems a good alternative
>
>> Please could you details what does means "rpmsg_ctrlN doesn't have a
>> "subsystem"." What exactly the udev is looking for? could it base it check on
>> the /dev/rpmsg_ctrl0 or /sys/bus/rpmsg/devices/...?
>>
>
> If I read the uevent messages correctly they seem to contain a SUBSYTEM=
> property when the class is provided. But I'm not sure about the reasons
> for that.
If it part of the udev requirement, i suppose that it is mandatory, and in this
case, declare the class in the core make sense.
I will send a new patchset that will squash all the remaining patches, taking
into account your comment.
Thanks,
Arnaud
>
> Regards,
> Bjorn
>
>> Thanks,
>> Arnaud
>>
>>>
>>> Regards,
>>> Bjorn
>>>
next prev parent reply other threads:[~2021-10-18 9:13 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-12 12:37 [PATCH v5 0/4] Restructure the rpmsg char to decorrelate the control part Arnaud Pouliquen
2021-07-12 12:37 ` [PATCH v5 1/4] rpmsg: char: Remove useless include Arnaud Pouliquen
2021-10-09 0:30 ` (subset) " Bjorn Andersson
2021-07-12 12:37 ` [PATCH v5 2/4] rpmsg: char: Export eptdev create an destroy functions Arnaud Pouliquen
2021-10-08 23:29 ` Bjorn Andersson
2021-10-11 10:39 ` Arnaud POULIQUEN
2021-07-12 12:37 ` [PATCH v5 3/4] rpmsg: Move the rpmsg control device from rpmsg_char to rpmsg_ctrl Arnaud Pouliquen
2021-10-08 23:35 ` Bjorn Andersson
2021-10-11 10:46 ` Arnaud POULIQUEN
2021-10-16 4:46 ` Bjorn Andersson
2021-10-18 9:13 ` Arnaud POULIQUEN [this message]
2021-10-19 3:08 ` Bjorn Andersson
2021-07-12 12:37 ` [PATCH v5 4/4] rpmsg: Update rpmsg_chrdev_register_device function Arnaud Pouliquen
2021-10-08 23:21 ` [PATCH v5 0/4] Restructure the rpmsg char to decorrelate the control part Bjorn Andersson
2021-10-11 10:38 ` Arnaud POULIQUEN
2021-10-19 3:28 ` Bjorn Andersson
2021-10-19 12:54 ` Arnaud POULIQUEN
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