Re: [PATCH] rpmsg: core: add support to power domains for devices

From: Arnaud Pouliquen
Date: Wed Sep 26 2018 - 08:48:24 EST


Hi Suman,


On 09/25/2018 09:02 PM, Suman Anna wrote:
> Hi Arnaud,
>
>> On 09/25/2018 02:25 AM, Suman Anna wrote:
>>> Hi Srinivas,
>>>
>>> On 06/15/2018 04:59 AM, Srinivas Kandagatla wrote:
>>>> Some of the rpmsg devices need to switch on power domains to communicate
>>>> with remote processor. For example on Qualcomm DB820c platform LPASS
>>>> power domain needs to switched on for any kind of audio services.
>>>> This patch adds the missing power domain support in rpmsg core.
>>>>
>>>> Without this patch attempting to play audio via QDSP on DB820c would
>>>> reboot the system.
>>>>
>>>> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
>>>> ---
>>>> drivers/rpmsg/rpmsg_core.c | 7 +++++++
>>>> 1 file changed, 7 insertions(+)
>>>>
>>>> diff --git a/drivers/rpmsg/rpmsg_core.c b/drivers/rpmsg/rpmsg_core.c
>>>> index b714a543a91d..8122807db380 100644
>>>> --- a/drivers/rpmsg/rpmsg_core.c
>>>> +++ b/drivers/rpmsg/rpmsg_core.c
>>>> @@ -15,6 +15,7 @@
>>>> #include <linux/module.h>
>>>> #include <linux/rpmsg.h>
>>>> #include <linux/of_device.h>
>>>> +#include <linux/pm_domain.h>
>>>> #include <linux/slab.h>
>>>>
>>>> #include "rpmsg_internal.h"
>>>> @@ -449,6 +450,10 @@ static int rpmsg_dev_probe(struct device *dev)
>>>> struct rpmsg_endpoint *ept = NULL;
>>>> int err;
>>>>
>>>> + err = dev_pm_domain_attach(dev, true);
>>>> + if (err)
>>>> + goto out;
>>>
>>> This patch has broken the virtio-rpmsg stack based rpmsg devices. These
>>> devices are non-DT and the rpmsg_dev_probe() is now failing with -19
>>> (-ENODEV) error code.
>>>
>>> Loic, Arnaud,
>>> Can one of you double-confirm this behavior on ST platforms as well?
>>> The patch came through 4.14.71 stable release and broke our downstream
>>> kernels.
>
>> I do not reproduce issue on 4.14.0 + your patch, on my ST platform (not
>> able to test on the LTS branch).
>> By looking the source code, seems that your issue is related to
>> genpd_dev_pm_attach that returns -ENODEV because you have
>> no remoteproc device node...
>> Do you have a rproc node defined in your DT? we have one.
>
> The dev here is not the remoteproc dev but the rpmsg device which does
> not have an OF node, and so I get the ENODEV due to the check on
> dev->of_node in genpd_dev_pm_attach. I do have DT remoteproc nodes.
>
> Are you publishing an rpmsg device from the remote side and are they
> being probed? Issue is seen only during the probe phase, you will not
> see any errors if the rpmsg devices are just being published and created.
Sorry something was wrong in my fw used yesterday for testing...so
forget my previous status.

I re-tested it and I have the same issue (-ENODEV) with rpmsg device
probed on ns announcement rpmsg from remote side.
So we confirm the issue.

Regards
Arnaud

>
> regards
> Suman
>
>>
>> Regards
>> Arnaud
>>
>>>
>>> regards
>>> Suman
>>>
>>>> +
>>>> if (rpdrv->callback) {
>>>> strncpy(chinfo.name, rpdev->id.name, RPMSG_NAME_SIZE);
>>>> chinfo.src = rpdev->src;
>>>> @@ -490,6 +495,8 @@ static int rpmsg_dev_remove(struct device *dev)
>>>>
>>>> rpdrv->remove(rpdev);
>>>>
>>>> + dev_pm_domain_detach(dev, true);
>>>> +
>>>> if (rpdev->ept)
>>>> rpmsg_destroy_ept(rpdev->ept);
>>>>
>>>>
>>>
>