[PATCH V3 2/2] scsi: ufs: introduce quirk to extend PA_HIBERN8TIME for UFS devices

[Manish Pandey]

Samsung UFS devices require additional time in hibern8 mode before exiting,
beyond the negotiated handshaking phase between the host and device.
Introduce a quirk to increase the PA_HIBERN8TIME parameter by 100 µs,
a value derived from experiments, to ensure a properhibernation process.

Signed-off-by: Manish Pandey <quic_mapa@xxxxxxxxxxx>
---
 drivers/ufs/core/ufshcd.c | 29 +++++++++++++++++++++++++++++
 include/ufs/ufs_quirks.h  |  6 ++++++
 2 files changed, 35 insertions(+)

diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index 8cae93fd221c..dce7625f9875 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -278,6 +278,7 @@ static const struct ufs_dev_quirk ufs_fixups[] = {
 	  .model = UFS_ANY_MODEL,
 	  .quirk = UFS_DEVICE_QUIRK_DELAY_BEFORE_LPM |
 		   UFS_DEVICE_QUIRK_HOST_PA_TACTIVATE |
+		   UFS_DEVICE_QUIRK_PA_HIBER8TIME |
 		   UFS_DEVICE_QUIRK_RECOVERY_FROM_DL_NAC_ERRORS },
 	{ .wmanufacturerid = UFS_VENDOR_SKHYNIX,
 	  .model = UFS_ANY_MODEL,
@@ -8470,6 +8471,31 @@ static int ufshcd_quirk_tune_host_pa_tactivate(struct ufs_hba *hba)
 	return ret;
 }
 
+/**
+ * ufshcd_quirk_override_pa_h8time - Ensures proper adjustment of PA_HIBERN8TIME.
+ * @hba: per-adapter instance
+ *
+ * Some UFS devices require specific adjustments to the PA_HIBERN8TIME parameter
+ * to ensure proper hibernation timing. This function retrieves the current
+ * PA_HIBERN8TIME value and increments it by 100us.
+ */
+static void ufshcd_quirk_override_pa_h8time(struct ufs_hba *hba)
+{
+	u32 pa_h8time;
+	int ret;
+
+	ret = ufshcd_dme_get(hba, UIC_ARG_MIB(PA_HIBERN8TIME), &pa_h8time);
+	if (ret) {
+		dev_err(hba->dev, "Failed to get PA_HIBERN8TIME: %d\n", ret);
+		return;
+	}
+
+	/* Increment by 1 to increase hibernation time by 100 µs */
+	ret = ufshcd_dme_set(hba, UIC_ARG_MIB(PA_HIBERN8TIME), pa_h8time + 1);
+	if (ret)
+		dev_err(hba->dev, "Failed updating PA_HIBERN8TIME: %d\n", ret);
+}
+
 static void ufshcd_tune_unipro_params(struct ufs_hba *hba)
 {
 	ufshcd_vops_apply_dev_quirks(hba);
@@ -8480,6 +8506,9 @@ static void ufshcd_tune_unipro_params(struct ufs_hba *hba)
 
 	if (hba->dev_quirks & UFS_DEVICE_QUIRK_HOST_PA_TACTIVATE)
 		ufshcd_quirk_tune_host_pa_tactivate(hba);
+
+	if (hba->dev_quirks & UFS_DEVICE_QUIRK_PA_HIBER8TIME)
+		ufshcd_quirk_override_pa_h8time(hba);
 }
 
 static void ufshcd_clear_dbg_ufs_stats(struct ufs_hba *hba)
diff --git a/include/ufs/ufs_quirks.h b/include/ufs/ufs_quirks.h
index 41ff44dfa1db..f52de5ed1b3b 100644
--- a/include/ufs/ufs_quirks.h
+++ b/include/ufs/ufs_quirks.h
@@ -107,4 +107,10 @@ struct ufs_dev_quirk {
  */
 #define UFS_DEVICE_QUIRK_DELAY_AFTER_LPM        (1 << 11)
 
+/*
+ * Some ufs devices may need more time to be in hibern8 before exiting.
+ * Enable this quirk to give it an additional 100us.
+ */
+#define UFS_DEVICE_QUIRK_PA_HIBER8TIME          (1 << 12)
+
 #endif /* UFS_QUIRKS_H_ */
-- 
2.17.1