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Date:   Thu, 23 Jul 2020 11:38:08 +0800
From:   hongwus@codeaurora.org
To:     Can Guo <cang@codeaurora.org>
Cc:     asutoshd@codeaurora.org, nguyenb@codeaurora.org,
        rnayak@codeaurora.org, sh425.lee@samsung.com,
        linux-scsi@vger.kernel.org, kernel-team@android.com,
        saravanak@google.com, salyzyn@google.com,
        Andy Gross <agross@kernel.org>,
        Bjorn Andersson <bjorn.andersson@linaro.org>,
        Alim Akhtar <alim.akhtar@samsung.com>,
        Avri Altman <avri.altman@wdc.com>,
        "James E.J. Bottomley" <jejb@linux.ibm.com>,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v5 3/9] ufs: ufs-qcom: Fix race conditions caused by func
 ufs_qcom_testbus_config
In-Reply-To: <1595471649-25675-4-git-send-email-cang@codeaurora.org>
References: <1595471649-25675-1-git-send-email-cang@codeaurora.org>
 <1595471649-25675-4-git-send-email-cang@codeaurora.org>
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On 2020-07-23 10:34, Can Guo wrote:
> If ufs_qcom_dump_dbg_regs() calls ufs_qcom_testbus_config() from
> ufshcd_suspend/resume and/or clk gate/ungate context, 
> pm_runtime_get_sync()
> and ufshcd_hold() will cause racing problems. Fix this by removing the
> unnecessary calls of pm_runtime_get_sync() and ufshcd_hold().
> 
> Signed-off-by: Can Guo <cang@codeaurora.org>
> ---
>  drivers/scsi/ufs/ufs-qcom.c | 5 -----
>  1 file changed, 5 deletions(-)
> 
> diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
> index 2e6ddb5..7da27ee 100644
> --- a/drivers/scsi/ufs/ufs-qcom.c
> +++ b/drivers/scsi/ufs/ufs-qcom.c
> @@ -1604,9 +1604,6 @@ int ufs_qcom_testbus_config(struct ufs_qcom_host 
> *host)
>  	 */
>  	}
>  	mask <<= offset;
> -
> -	pm_runtime_get_sync(host->hba->dev);
> -	ufshcd_hold(host->hba, false);
>  	ufshcd_rmwl(host->hba, TEST_BUS_SEL,
>  		    (u32)host->testbus.select_major << 19,
>  		    REG_UFS_CFG1);
> @@ -1619,8 +1616,6 @@ int ufs_qcom_testbus_config(struct ufs_qcom_host 
> *host)
>  	 * committed before returning.
>  	 */
>  	mb();
> -	ufshcd_release(host->hba);
> -	pm_runtime_put_sync(host->hba->dev);
> 
>  	return 0;
>  }


Reviewed-by: Hongwu Su <hongwus@codeaurora.org>