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From:   Can Guo <cang@codeaurora.org>
To:     asutoshd@codeaurora.org, nguyenb@codeaurora.org,
        hongwus@codeaurora.org, rnayak@codeaurora.org,
        linux-scsi@vger.kernel.org, kernel-team@android.com,
        saravanak@google.com, salyzyn@google.com, cang@codeaurora.org
Cc:     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 (open list:ARM/QUALCOMM SUPPORT),
        linux-kernel@vger.kernel.org (open list)
Subject: [PATCH 2/8] ufs: ufs-qcom: Fix race conditions caused by func ufs_qcom_testbus_config
Date:   Fri, 31 Jul 2020 01:08:02 -0700
Message-Id: <1596182890-10086-3-git-send-email-cang@codeaurora.org>
In-Reply-To: <1596182890-10086-1-git-send-email-cang@codeaurora.org>
References: <1596182890-10086-1-git-send-email-cang@codeaurora.org>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

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>
Reviewed-by: Hongwu Su <hongwus@codeaurora.org>
Reviewed-by: Avri Altman <avri.altman@wdc.com>
Reviewed-by: Bean Huo <beanhuo@micron.com>

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;
 }
-- 
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