scsi: ufs-qcom: avoid sleep in atomic context

Minimize the number of debug registers printed in atomic context
during error and also avoid sleeping in atomic context.

Change-Id: Ic5f3260c433e2d99d3a87a80dae0106dc622c4b7
Signed-off-by: Venkat Gopalakrishnan <venkatg@codeaurora.org>

3 files changed, 22 insertions, 8 deletions

diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
index ad4b6ffef36e..fbf6197de0f8 100644
--- a/drivers/scsi/ufs/ufs-qcom.c
+++ b/drivers/scsi/ufs/ufs-qcom.c
@@ -2570,16 +2570,19 @@ 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)
 {
 	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
 	struct phy *phy = host->generic_phy;
 
 	ufs_qcom_dump_regs(hba, REG_UFS_SYS1CLK_1US, 16,
 			"HCI Vendor Specific Registers ");
+	ufs_qcom_print_hw_debug_reg_all(hba, NULL, ufs_qcom_dump_regs_wrapper);
+
+	if (no_sleep)
+		return;
 
 	/* 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);
 	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 d478767ad3dd..29d2f9562df3 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -539,7 +539,7 @@ static void ufshcd_print_uic_err_hist(struct ufs_hba *hba,
 	}
 }
 
-static void ufshcd_print_host_regs(struct ufs_hba *hba)
+static inline void __ufshcd_print_host_regs(struct ufs_hba *hba, bool no_sleep)
 {
 	if (!(hba->ufshcd_dbg_print & UFSHCD_DBG_PRINT_HOST_REGS_EN))
 		return;
@@ -571,7 +571,12 @@ 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
@@ -5029,7 +5034,12 @@ ufshcd_transfer_rsp_status(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
 		dev_err(hba->dev,
 				"OCS error from controller = %x for tag %d\n",
 				ocs, lrbp->task_tag);
-		ufshcd_print_host_regs(hba);
+		/*
+		 * This is called in interrupt context, hence avoid sleep
+		 * while printing debug registers. Also print only the minimum
+		 * debug registers needed to debug OCS failure.
+		 */
+		__ufshcd_print_host_regs(hba, true);
 		ufshcd_print_host_state(hba);
 		break;
 	} /* end of switch */
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index a6298f614a0b..a3e1353ffad9 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -334,7 +334,7 @@ struct ufs_hba_variant_ops {
 	int	(*suspend)(struct ufs_hba *, enum ufs_pm_op);
 	int	(*resume)(struct ufs_hba *, enum ufs_pm_op);
 	int	(*full_reset)(struct ufs_hba *);
-	void	(*dbg_register_dump)(struct ufs_hba *hba);
+	void	(*dbg_register_dump)(struct ufs_hba *hba, bool no_sleep);
 	int	(*update_sec_cfg)(struct ufs_hba *hba, bool restore_sec_cfg);
 	u32	(*get_scale_down_gear)(struct ufs_hba *);
 	int	(*set_bus_vote)(struct ufs_hba *, bool);
@@ -1241,10 +1241,11 @@ static inline int ufshcd_vops_full_reset(struct ufs_hba *hba)
 }
 
 
-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->var && hba->var->vops && hba->var->vops->dbg_register_dump)
-		hba->var->vops->dbg_register_dump(hba);
+		hba->var->vops->dbg_register_dump(hba, no_sleep);
 }
 
 static inline int ufshcd_vops_update_sec_cfg(struct ufs_hba *hba,