linux-kernel - [PATCH v2] scsi: ufs: Fix registers dump vops caused scheduling while atomic

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Message-Id: <1580886875-31967-1-git-send-email-cang@codeaurora.org>
Date:   Tue,  4 Feb 2020 23:14:29 -0800
From:   Can Guo <cang@...eaurora.org>
To:     asutoshd@...eaurora.org, nguyenb@...eaurora.org,
        hongwus@...eaurora.org, rnayak@...eaurora.org,
        linux-scsi@...r.kernel.org, kernel-team@...roid.com,
        saravanak@...gle.com, salyzyn@...gle.com, cang@...eaurora.org
Cc:     Andy Gross <agross@...nel.org>,
        Bjorn Andersson <bjorn.andersson@...aro.org>,
        Alim Akhtar <alim.akhtar@...sung.com>,
        Avri Altman <avri.altman@....com>,
        "James E.J. Bottomley" <jejb@...ux.ibm.com>,
        "Martin K. Petersen" <martin.petersen@...cle.com>,
        Stanley Chu <stanley.chu@...iatek.com>,
        Bean Huo <beanhuo@...ron.com>,
        Bart Van Assche <bvanassche@....org>,
        Venkat Gopalakrishnan <venkatg@...eaurora.org>,
        Tomas Winkler <tomas.winkler@...el.com>,
        linux-arm-msm@...r.kernel.org (open list:ARM/QUALCOMM SUPPORT),
        linux-kernel@...r.kernel.org (open list)
Subject: [PATCH v2] scsi: ufs: Fix registers dump vops caused scheduling while atomic

Reigsters dump intiated from atomic context should not sleep. To fix it,
add one boolean parameter to register dump vops to inform vendor driver if
sleep is allowed or not.

Signed-off-by: Can Guo <cang@...eaurora.org>

diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
index 3b5b2d9..c30139c 100644
--- a/drivers/scsi/ufs/ufs-qcom.c
+++ b/drivers/scsi/ufs/ufs-qcom.c
@@ -1619,13 +1619,17 @@ static void ufs_qcom_print_unipro_testbus(struct ufs_hba *hba)
 	kfree(testbus);
 }
 
-static void ufs_qcom_dump_dbg_regs(struct ufs_hba *hba)
+static void ufs_qcom_dump_dbg_regs(struct ufs_hba *hba, bool no_sleep)
 {
 	ufshcd_dump_regs(hba, REG_UFS_SYS1CLK_1US, 16 * 4,
 			 "HCI Vendor Specific Registers ");
 
 	/* sleep a bit intermittently as we are dumping too much data */
 	ufs_qcom_print_hw_debug_reg_all(hba, NULL, ufs_qcom_dump_regs_wrapper);
+
+	if (no_sleep)
+		return;
+
 	usleep_range(1000, 1100);
 	ufs_qcom_testbus_read(hba);
 	usleep_range(1000, 1100);
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 0ac5d47..c585457 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -398,7 +398,7 @@ static void ufshcd_print_err_hist(struct ufs_hba *hba,
 		dev_err(hba->dev, "No record of %s\n", err_name);
 }
 
-static void ufshcd_print_host_regs(struct ufs_hba *hba)
+static inline void __ufshcd_print_host_regs(struct ufs_hba *hba, bool no_sleep)
 {
 	ufshcd_dump_regs(hba, 0, UFSHCI_REG_SPACE_SIZE, "host_regs: ");
 	dev_err(hba->dev, "hba->ufs_version = 0x%x, hba->capabilities = 0x%x\n",
@@ -430,7 +430,17 @@ static void ufshcd_print_host_regs(struct ufs_hba *hba)
 
 	ufshcd_print_clk_freqs(hba);
 
-	ufshcd_vops_dbg_register_dump(hba);
+	ufshcd_vops_dbg_register_dump(hba, no_sleep);
+}
+
+static void ufshcd_print_host_regs(struct ufs_hba *hba)
+{
+	__ufshcd_print_host_regs(hba, false);
+}
+
+static void ufshcd_print_host_regs_atomic(struct ufs_hba *hba)
+{
+	__ufshcd_print_host_regs(hba, true);
 }
 
 static
@@ -4821,7 +4831,7 @@ static void ufshcd_slave_destroy(struct scsi_device *sdev)
 		dev_err(hba->dev,
 				"OCS error from controller = %x for tag %d\n",
 				ocs, lrbp->task_tag);
-		ufshcd_print_host_regs(hba);
+		ufshcd_print_host_regs_atomic(hba);
 		ufshcd_print_host_state(hba);
 		break;
 	} /* end of switch */
@@ -5617,7 +5627,7 @@ static irqreturn_t ufshcd_check_errors(struct ufs_hba *hba)
 					__func__, hba->saved_err,
 					hba->saved_uic_err);
 
-				ufshcd_print_host_regs(hba);
+				ufshcd_print_host_regs_atomic(hba);
 				ufshcd_print_pwr_info(hba);
 				ufshcd_print_tmrs(hba, hba->outstanding_tasks);
 				ufshcd_print_trs(hba, hba->outstanding_reqs,
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index 2ae6c7c..3de7cbb 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -323,7 +323,7 @@ struct ufs_hba_variant_ops {
 	int	(*apply_dev_quirks)(struct ufs_hba *hba);
 	int     (*suspend)(struct ufs_hba *, enum ufs_pm_op);
 	int     (*resume)(struct ufs_hba *, enum ufs_pm_op);
-	void	(*dbg_register_dump)(struct ufs_hba *hba);
+	void	(*dbg_register_dump)(struct ufs_hba *hba, bool no_sleep);
 	int	(*phy_initialization)(struct ufs_hba *);
 	void	(*device_reset)(struct ufs_hba *hba);
 };
@@ -1078,10 +1078,11 @@ static inline int ufshcd_vops_resume(struct ufs_hba *hba, enum ufs_pm_op op)
 	return 0;
 }
 
-static inline void ufshcd_vops_dbg_register_dump(struct ufs_hba *hba)
+static inline void ufshcd_vops_dbg_register_dump(struct ufs_hba *hba,
+						 bool no_sleep)
 {
 	if (hba->vops && hba->vops->dbg_register_dump)
-		hba->vops->dbg_register_dump(hba);
+		hba->vops->dbg_register_dump(hba, no_sleep);
 }
 
 static inline void ufshcd_vops_device_reset(struct ufs_hba *hba)
-- 
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