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Message-ID: <efe0b912-24d8-9617-ce6a-aca5dfba6910@linaro.org>
Date:   Wed, 14 Jun 2023 15:50:57 +0200
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Subject: Re: [PATCH RFC] media: camss: Intepret OF graph connections more
 sensibly
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To:     Bryan O'Donoghue <bryan.odonoghue@linaro.org>,
        Robert Foss <rfoss@kernel.org>,
        Todor Tomov <todor.too@gmail.com>,
        Andy Gross <agross@kernel.org>,
        Bjorn Andersson <andersson@kernel.org>,
        Mauro Carvalho Chehab <mchehab@kernel.org>
Cc:     Marijn Suijten <marijn.suijten@somainline.org>,
        Yassine Oudjana <y.oudjana@protonmail.com>,
        linux-media@vger.kernel.org, linux-arm-msm@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <20230614-topic-camss_grpah-v1-1-5f4b516310fa@linaro.org>
 <8f53da6d-76ec-a7e1-8308-b676930d224c@linaro.org>
From:   Konrad Dybcio <konrad.dybcio@linaro.org>
In-Reply-To: <8f53da6d-76ec-a7e1-8308-b676930d224c@linaro.org>
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On 14.06.2023 15:48, Bryan O'Donoghue wrote:
> On 14/06/2023 14:22, Konrad Dybcio wrote:
>> Not all endpoints of camss have to be populated. In fact, most of the
>> time they shouldn't be as n-th auxilliary cameras are usually ewaste.
>>
>> Don't fail probing the entire camss even even one endpoint is not
>> linked and throw an error when none is found.
>>
>> Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
>> ---
>>   drivers/media/platform/qcom/camss/camss.c | 7 +++----
>>   1 file changed, 3 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/media/platform/qcom/camss/camss.c b/drivers/media/platform/qcom/camss/camss.c
>> index 1ef26aea3eae..3aa03fbc94e2 100644
>> --- a/drivers/media/platform/qcom/camss/camss.c
>> +++ b/drivers/media/platform/qcom/camss/camss.c
>> @@ -1084,9 +1084,8 @@ static int camss_of_parse_ports(struct camss *camss)
>>             remote = of_graph_get_remote_port_parent(node);
>>           if (!remote) {
>> -            dev_err(dev, "Cannot get remote parent\n");
>> -            ret = -EINVAL;
>> -            goto err_cleanup;
>> +            of_node_put(node);
>> +            continue;
>>           }
>>             csd = v4l2_async_nf_add_fwnode(&camss->notifier,
>> @@ -1105,7 +1104,7 @@ static int camss_of_parse_ports(struct camss *camss)
>>           num_subdevs++;
>>       }
>>   -    return num_subdevs;
>> +    return num_subdevs ? num_subdevs : -EINVAL;
>>     err_cleanup:
>>       of_node_put(node);
>>
>> ---
>> base-commit: b16049b21162bb649cdd8519642a35972b7910fe
>> change-id: 20230614-topic-camss_grpah-39f9a4f7420c
>>
>> Best regards,
> 
> Can you give an example of the DT that is causing this ?
None upstream (8916 has a single port and 845c's sec camera has
never been enabled), but it's easy to spot if you leave csiphy0_ep
unoccupied and add something to csiphyN_ep for N>=1

Konrad
> 
> ---
> bod