[RFC][PATCH] scsi: ufs: Fix hynix ufs bug with quirk on hi36xx SoC

[John Stultz]

From: Wei Li <liwei213@xxxxxxxxxx>

Hynix ufs has deviations on hi36xx platform which will result in
ufs bursts transfer failures.

To fix the problem, the Hynix device must set the register
VS_DebugSaveConfigTime to 0x10, which will set time reference
for SaveConfigTime is 250 ns. The time reference for SaveConfigTime
is 40 ns by default.

Feedback would be greatly appreciated!

Cc: Vinayak Holikatti <vinholikatti@xxxxxxxxx>
Cc: "James E.J. Bottomley" <jejb@xxxxxxxxxxxxxxxxxx>
Cc: "Martin K. Petersen" <martin.petersen@xxxxxxxxxx>
Cc: linux-scsi@xxxxxxxxxxxxxxx
Signed-off-by: Wei Li <liwei213@xxxxxxxxxx>
Signed-off-by: Dmitry Shmidt <dimitrysh@xxxxxxxxxx>
[jstultz: Forward ported from older code, slight tweak to commit message]
Signed-off-by: John Stultz <john.stultz@xxxxxxxxxx>
---
 drivers/scsi/ufs/ufs-hisi.c   | 9 +++++++++
 drivers/scsi/ufs/ufs_quirks.h | 6 ++++++
 drivers/scsi/ufs/ufshcd.c     | 2 ++
 3 files changed, 17 insertions(+)

diff --git a/drivers/scsi/ufs/ufs-hisi.c b/drivers/scsi/ufs/ufs-hisi.c
index 46df707..452e19f 100644
--- a/drivers/scsi/ufs/ufs-hisi.c
+++ b/drivers/scsi/ufs/ufs-hisi.c
@@ -20,6 +20,7 @@
 #include "unipro.h"
 #include "ufs-hisi.h"
 #include "ufshci.h"
+#include "ufs_quirks.h"
 
 static int ufs_hisi_check_hibern8(struct ufs_hba *hba)
 {
@@ -390,6 +391,14 @@ static void ufs_hisi_set_dev_cap(struct ufs_hisi_dev_params *hisi_param)
 
 static void ufs_hisi_pwr_change_pre_change(struct ufs_hba *hba)
 {
+	if (hba->dev_quirks & UFS_DEVICE_QUIRK_HOST_VS_DEBUGSAVECONFIGTIME) {
+		pr_info("ufs flash device must set VS_DebugSaveConfigTime 0x10\n");
+		/* VS_DebugSaveConfigTime */
+		ufshcd_dme_set(hba, UIC_ARG_MIB(0xD0A0), 0x10);
+		/* sync length */
+		ufshcd_dme_set(hba, UIC_ARG_MIB(0x1556), 0x48);
+	}
+
 	/* update */
 	ufshcd_dme_set(hba, UIC_ARG_MIB(0x15A8), 0x1);
 	/* PA_TxSkip */
diff --git a/drivers/scsi/ufs/ufs_quirks.h b/drivers/scsi/ufs/ufs_quirks.h
index 71f73d1..5d2dfdb 100644
--- a/drivers/scsi/ufs/ufs_quirks.h
+++ b/drivers/scsi/ufs/ufs_quirks.h
@@ -131,4 +131,10 @@ struct ufs_dev_fix {
  */
 #define UFS_DEVICE_QUIRK_HOST_PA_SAVECONFIGTIME	(1 << 8)
 
+/*
+ * Some UFS devices require VS_DebugSaveConfigTime is 0x10,
+ * enabling this quirk ensure this.
+ */
+#define UFS_DEVICE_QUIRK_HOST_VS_DEBUGSAVECONFIGTIME	(1 << 9)
+
 #endif /* UFS_QUIRKS_H_ */
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 9d5d2ca..3389e36 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -230,6 +230,8 @@ static struct ufs_dev_fix ufs_fixups[] = {
 	UFS_FIX(UFS_VENDOR_SKHYNIX, UFS_ANY_MODEL, UFS_DEVICE_NO_VCCQ),
 	UFS_FIX(UFS_VENDOR_SKHYNIX, UFS_ANY_MODEL,
 		UFS_DEVICE_QUIRK_HOST_PA_SAVECONFIGTIME),
+	UFS_FIX(UFS_VENDOR_SKHYNIX, UFS_ANY_MODEL,
+		UFS_DEVICE_QUIRK_HOST_VS_DEBUGSAVECONFIGTIME),
 
 	END_FIX
 };
-- 
2.7.4