Re: [PATCH v3] coresight: core: Fix coresight device probe failure issue

From: Suzuki K Poulose <suzuki.poulose@arm.com>
To: Jinlong Mao <quic_jinlmao@quicinc.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>
Subject: Re: [PATCH v3] coresight: core: Fix coresight device probe failure issue
Date: Tue, 15 Mar 2022 08:42:13 +0000	[thread overview]
Message-ID: <99845680-c2a5-2538-a57c-6fbf395faa8b@arm.com> (raw)
In-Reply-To: <9cbb2e86-640f-4b5d-22ff-00c63a1b9743@quicinc.com>

On 15/03/2022 08:36, Jinlong Mao wrote:
> 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 ?

Thats what I just said above. The patch looks good to me, I can queue
this in the next cycle.

Kind regards
Suzuki

> 
> Thanks
> Jinlong Mao