[PATCH v1 1/1] ufs: core: Add host quirk QUIRK_MCQ_EXPAND_QUEUE_SLOT

[Chun-Hung Wu]

From: Alice Chao <alice.chao@xxxxxxxxxxxx>

This quirk needs to be enabled if the host controller cannot
distinguish queue full or empty.

Signed-off-by: Alice Chao <alice.chao@xxxxxxxxxxxx>
---
 drivers/ufs/core/ufs-mcq.c |  5 ++++-
 include/ufs/ufshcd.h       | 11 +++++++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/drivers/ufs/core/ufs-mcq.c b/drivers/ufs/core/ufs-mcq.c
index 2ba8ec254dce..9b8ed3f9a349 100644
--- a/drivers/ufs/core/ufs-mcq.c
+++ b/drivers/ufs/core/ufs-mcq.c
@@ -436,7 +436,10 @@ int ufshcd_mcq_init(struct ufs_hba *hba)
 
 	for (i = 0; i < hba->nr_hw_queues; i++) {
 		hwq = &hba->uhq[i];
-		hwq->max_entries = hba->nutrs;
+		if (ufshcd_is_mcq_expand_queue_slot(hba))
+			hwq->max_entries = hba->nutrs + 1;
+		else
+			hwq->max_entries = hba->nutrs;
 		spin_lock_init(&hwq->sq_lock);
 		spin_lock_init(&hwq->cq_lock);
 		mutex_init(&hwq->sq_mutex);
diff --git a/include/ufs/ufshcd.h b/include/ufs/ufshcd.h
index 7d07b256e906..44de185501b5 100644
--- a/include/ufs/ufshcd.h
+++ b/include/ufs/ufshcd.h
@@ -643,6 +643,12 @@ enum ufshcd_quirks {
 	 * thus need this quirk to skip related flow.
 	 */
 	UFSHCD_QUIRK_MCQ_BROKEN_RTC			= 1 << 21,
+
+	/*
+	 * This quirk needs to be enabled if the host controller cannot
+	 * distinguish queue full or empty.
+	 */
+	UFSHCD_QUIRK_MCQ_EXPAND_QUEUE_SLOT              = 1 << 22,
 };
 
 enum ufshcd_caps {
@@ -1198,6 +1204,11 @@ static inline bool ufshcd_enable_wb_if_scaling_up(struct ufs_hba *hba)
 	return hba->caps & UFSHCD_CAP_WB_WITH_CLK_SCALING;
 }
 
+static inline bool ufshcd_is_mcq_expand_queue_slot(struct ufs_hba *hba)
+{
+	return hba->quirks & UFSHCD_QUIRK_MCQ_EXPAND_QUEUE_SLOT;
+}
+
 #define ufsmcq_writel(hba, val, reg)	\
 	writel((val), (hba)->mcq_base + (reg))
 #define ufsmcq_readl(hba, reg)	\
-- 
2.18.0