[PATCH 2/2] ufs: don't use the fair tag sharings

From: Ed Tsai <ed.tsai@mediatek.com>
To: <axboe@kernel.dk>
Cc: <linux-block@vger.kernel.org>, <linux-scsi@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>, <martin.petersen@oracle.com>,
	<bvanassche@acm.org>, <stanley.chu@mediatek.com>,
	<peter.wang@mediatek.com>, <chun-hung.wu@mediatek.com>,
	<alice.chao@mediatek.com>, <powen.kao@mediatek.com>,
	<naomi.chu@mediatek.com>, <wsd_upstream@mediatek.com>,
	Ed Tsai <ed.tsai@mediatek.com>
Subject: [PATCH 2/2] ufs: don't use the fair tag sharings
Date: Tue, 9 May 2023 14:52:30 +0800	[thread overview]
Message-ID: <20230509065230.32552-3-ed.tsai@mediatek.com> (raw)
In-Reply-To: <20230509065230.32552-1-ed.tsai@mediatek.com>

The tags allocation is limited by the fair sharing algorithm. It hurts
the performance for UFS devices, because the queue depth of general I/O
is reduced by half once the UFS send a control command.

Signed-off-by: Ed Tsai <ed.tsai@mediatek.com>
---
 drivers/ufs/core/ufshcd.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index 17d7bb875fee..e96a50265285 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -5149,6 +5149,9 @@ static int ufshcd_slave_configure(struct scsi_device *sdev)
 	blk_queue_update_dma_pad(q, PRDT_DATA_BYTE_COUNT_PAD - 1);
 	if (hba->quirks & UFSHCD_QUIRK_4KB_DMA_ALIGNMENT)
 		blk_queue_update_dma_alignment(q, 4096 - 1);
+
+	blk_queue_flag_clear(QUEUE_FLAG_FAIR_TAG_SHARING, q);
+
 	/*
 	 * Block runtime-pm until all consumers are added.
 	 * Refer ufshcd_setup_links().
-- 
2.18.0

