Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <9cbb2e86-640f-4b5d-22ff-00c63a1b9743@quicinc.com>
Date:   Tue, 15 Mar 2022 16:36:48 +0800
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101
 Thunderbird/91.3.0
Subject: Re: [PATCH v3] coresight: core: Fix coresight device probe failure
 issue
Content-Language: en-US
To:     Suzuki K Poulose <suzuki.poulose@arm.com>,
        Mathieu Poirier <mathieu.poirier@linaro.org>,
        Mike Leach <mike.leach@linaro.org>,
        Leo Yan <leo.yan@linaro.org>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>
CC:     <coresight@lists.linaro.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>, <linux-arm-msm@vger.kernel.org>,
        "Tingwei Zhang" <quic_tingweiz@quicinc.com>,
        Yuanfang Zhang <quic_yuanfang@quicinc.com>,
        Tao Zhang <quic_taozha@quicinc.com>,
        Hao Zhang <quic_hazha@quicinc.com>
References: <20220309142206.15632-1-quic_jinlmao@quicinc.com>
 <a1790ad9-b5e0-9a00-debc-fc8ef2c757cb@arm.com>
From:   Jinlong Mao <quic_jinlmao@quicinc.com>
In-Reply-To: <a1790ad9-b5e0-9a00-debc-fc8ef2c757cb@arm.com>
Content-Type: text/plain; charset="UTF-8"; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 3/10/2022 5:10 PM, Suzuki K Poulose wrote:
> Hi Jinlong
>
>
> On 09/03/2022 14:22, Mao Jinlong wrote:
>> It is possibe that probe failure issue happens when the device
>> and its child_device's probe happens at the same time.
>> In coresight_make_links, has_conns_grp is true for parent, but
>> has_conns_grp is false for child device as has_conns_grp is set
>> to true in coresight_create_conns_sysfs_group. The probe of parent
>> device will fail at this condition. Add has_conns_grp check for
>> child device before make the links and make the process from
>> device_register to connection_create be atomic to avoid this
>> probe failure issue.
>>
>> Suggested-by: Suzuki K Poulose <suzuki.poulose@arm.com>
>> Suggested-by: Mike Leach <mike.leach@linaro.org>
>> Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com>
>
> Thanks for the rework. The patch looks good to me.
>
> Suzuki
Thanks Suzuki.

Hi Mathieu & Mike,

Could you please help to review and provide your comments for the PATCH V3 ?

Thanks
Jinlong Mao