[PATCH 5.5 196/257] scsi: ufs: fix Auto-Hibern8 error detection

[Greg Kroah-Hartman]

From: Stanley Chu <stanley.chu@xxxxxxxxxxxx>

commit 5a244e0ea67b293abb1d26c825db2ddde5f2862f upstream.

Auto-Hibern8 may be disabled by some vendors or sysfs in runtime even if
Auto-Hibern8 capability is supported by host. If Auto-Hibern8 capability is
supported by host but not actually enabled, Auto-Hibern8 error shall not
happen.

To fix this, provide a way to detect if Auto-Hibern8 is actually enabled
first, and bypass Auto-Hibern8 disabling case in
ufshcd_is_auto_hibern8_error().

Fixes: 821744403913 ("scsi: ufs: Add error-handling of Auto-Hibernate")
Cc: stable@xxxxxxxxxxxxxxx
Link: https://lore.kernel.org/r/20200129105251.12466-4-stanley.chu@xxxxxxxxxxxx
Reviewed-by: Bean Huo <beanhuo@xxxxxxxxxx>
Reviewed-by: Alim Akhtar <alim.akhtar@xxxxxxxxxxx>
Reviewed-by: Asutosh Das <asutoshd@xxxxxxxxxxxxxx>
Reviewed-by: Can Guo <cang@xxxxxxxxxxxxxx>
Signed-off-by: Stanley Chu <stanley.chu@xxxxxxxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/scsi/ufs/ufshcd.c |    3 ++-
 drivers/scsi/ufs/ufshcd.h |    6 ++++++
 2 files changed, 8 insertions(+), 1 deletion(-)

--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -5513,7 +5513,8 @@ static irqreturn_t ufshcd_update_uic_err
 static bool ufshcd_is_auto_hibern8_error(struct ufs_hba *hba,
 					 u32 intr_mask)
 {
-	if (!ufshcd_is_auto_hibern8_supported(hba))
+	if (!ufshcd_is_auto_hibern8_supported(hba) ||
+	    !ufshcd_is_auto_hibern8_enabled(hba))
 		return false;
 
 	if (!(intr_mask & UFSHCD_UIC_HIBERN8_MASK))
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -55,6 +55,7 @@
 #include <linux/clk.h>
 #include <linux/completion.h>
 #include <linux/regulator/consumer.h>
+#include <linux/bitfield.h>
 #include "unipro.h"
 
 #include <asm/irq.h>
@@ -781,6 +782,11 @@ static inline bool ufshcd_is_auto_hibern
 	return (hba->capabilities & MASK_AUTO_HIBERN8_SUPPORT);
 }
 
+static inline bool ufshcd_is_auto_hibern8_enabled(struct ufs_hba *hba)
+{
+	return FIELD_GET(UFSHCI_AHIBERN8_TIMER_MASK, hba->ahit) ? true : false;
+}
+
 #define ufshcd_writel(hba, val, reg)	\
 	writel((val), (hba)->mmio_base + (reg))
 #define ufshcd_readl(hba, reg)	\