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From: Nitin Rawat <quic_nitirawa@quicinc.com>
To: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>,
	<vkoul@kernel.org>, <kishon@kernel.org>,
	<manivannan.sadhasivam@linaro.org>,
	<James.Bottomley@HansenPartnership.com>,
	<martin.petersen@oracle.com>, <bvanassche@acm.org>,
	<andersson@kernel.org>, <neil.armstrong@linaro.org>
Cc: <quic_rdwivedi@quicinc.com>, <quic_cang@quicinc.com>,
	<linux-arm-msm@vger.kernel.org>, <linux-phy@lists.infradead.org>,
	<linux-kernel@vger.kernel.org>, <linux-scsi@vger.kernel.org>
Subject: Re: [PATCH V4 10/11] scsi: ufs: qcom : Introduce phy_power_on/off wrapper function
Date: Fri, 9 May 2025 17:19:16 +0530	[thread overview]
Message-ID: <be69cd1e-c04c-4976-9be1-390631316d3f@quicinc.com> (raw)
In-Reply-To: <58d913b8-0715-41b0-883a-423f29cb5a8c@oss.qualcomm.com>



On 5/9/2025 5:07 PM, Konrad Dybcio wrote:
> On 5/3/25 6:24 PM, Nitin Rawat wrote:
>> Introduce ufs_qcom_phy_power_on and ufs_qcom_phy_power_off wrapper
>> functions with mutex protection to ensure safe usage of is_phy_pwr_on
>> and prevent possible race conditions.
>>
>> Co-developed-by: Can Guo <quic_cang@quicinc.com>
>> Signed-off-by: Can Guo <quic_cang@quicinc.com>
>> Signed-off-by: Nitin Rawat <quic_nitirawa@quicinc.com>
>> ---
> 
> The PHY framework does the same thing internally already, this seems
> unnecessary

Hi Konrad,

Thanks for the review. There are scenarios where ufshcd_link_startup() 
can call ufshcd_vops_link_startup_notify() multiple times during 
retries. This leads to the PHY reference count increasing continuously, 
preventing proper re-initialization of the PHY.

Recently, this issue was addressed with patch 7bac65687510 ("scsi: ufs:
qcom: Power off the PHY if it was already powered on in 
ufs_qcom_power_up_sequence()"). However, I still want to maintain a 
reference count (ref_cnt) to safeguard against similar conditions in the 
code. Additionally, this approach helps avoid unnecessary phy_power_on 
and phy_power_off calls. Please let me know your thoughts.

Regards,
Nitin


> 
> Konrad


-- 
linux-phy mailing list
linux-phy@lists.infradead.org
https://lists.infradead.org/mailman/listinfo/linux-phy

  reply	other threads:[~2025-05-09 12:43 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-05-03 16:24 [PATCH V4 00/11] Refactor ufs phy powerup sequence Nitin Rawat
2025-05-03 16:24 ` [PATCH V4 01/11] scsi: ufs: qcom: add a new phy calibrate API call Nitin Rawat
2025-05-09 12:06   ` Konrad Dybcio
2025-05-03 16:24 ` [PATCH V4 02/11] phy: qcom-qmp-ufs: Rename qmp_ufs_enable and qmp_ufs_power_on Nitin Rawat
2025-05-03 16:24 ` [PATCH V4 03/11] phy: qcom-qmp-ufs: Refactor phy_power_on and phy_calibrate callbacks Nitin Rawat
2025-05-03 16:24 ` [PATCH V4 04/11] phy: qcom-qmp-ufs: Refactor UFS PHY reset Nitin Rawat
2025-05-04 15:27   ` Dmitry Baryshkov
2025-05-03 16:24 ` [PATCH V4 05/11] phy: qcom-qmp-ufs: Remove qmp_ufs_com_init() Nitin Rawat
2025-05-03 16:24 ` [PATCH V4 06/11] phy: qcom-qmp-ufs: Rename qmp_ufs_power_off Nitin Rawat
2025-05-04 15:37   ` Dmitry Baryshkov
2025-05-04 15:52     ` Nitin Rawat
2025-05-06 11:53       ` Dmitry Baryshkov
2025-05-07 15:05         ` Nitin Rawat
2025-05-04 15:57     ` Dmitry Baryshkov
2025-05-03 16:24 ` [PATCH V4 07/11] phy: qcom-qmp-ufs: Remove qmp_ufs_exit() and Inline qmp_ufs_com_exit() Nitin Rawat
2025-05-04 15:56   ` Dmitry Baryshkov
2025-05-03 16:24 ` [PATCH V4 08/11] phy: qcom-qmp-ufs: refactor qmp_ufs_power_off Nitin Rawat
2025-05-04 15:57   ` Dmitry Baryshkov
2025-05-03 16:24 ` [PATCH V4 09/11] scsi: ufs: qcom : Refactor phy_power_on/off calls Nitin Rawat
2025-05-09 11:35   ` Konrad Dybcio
2025-05-10 13:49     ` Nitin Rawat
2025-05-03 16:24 ` [PATCH V4 10/11] scsi: ufs: qcom : Introduce phy_power_on/off wrapper function Nitin Rawat
2025-05-09 11:37   ` Konrad Dybcio
2025-05-09 11:49     ` Nitin Rawat [this message]
2025-05-09 12:00       ` Konrad Dybcio
2025-05-13 13:12         ` Nitin Rawat
2025-05-03 16:24 ` [PATCH V4 11/11] scsi: ufs: qcom: Prevent calling phy_exit before phy_init Nitin Rawat
2025-05-09 11:38   ` Konrad Dybcio
2025-05-09 11:50     ` Nitin Rawat

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