Linux SCSI subsystem development
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From: Nitin Rawat <nitin.rawat@oss.qualcomm.com>
To: mani@kernel.org, James.Bottomley@HansenPartnership.com,
	martin.petersen@oracle.com
Cc: linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-scsi@vger.kernel.org,
	Nitin Rawat <nitin.rawat@oss.qualcomm.com>
Subject: [PATCH V1 3/3] ufs: ufs-qcom: Fix sequential read variance
Date: Thu, 22 Jan 2026 19:43:31 +0530	[thread overview]
Message-ID: <20260122141331.239354-4-nitin.rawat@oss.qualcomm.com> (raw)
In-Reply-To: <20260122141331.239354-1-nitin.rawat@oss.qualcomm.com>

The current devfreq downdifferential threshold of 5% causes overly
aggressive frequency downscaling, leading to performance degradation
sometimes during sequential read workloads.

Update the UFS devfreq downdifferential threshold to 65.
This widens the hysteresis window and prevents overly aggressive
downscaling, ensuring that frequency is maintained for loads above 5%
and scaling down occurs only when utilization falls below this level,
while scale-up still triggers above the 70% threshold.

Signed-off-by: Nitin Rawat <nitin.rawat@oss.qualcomm.com>
---
 drivers/ufs/host/ufs-qcom.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/ufs/host/ufs-qcom.c b/drivers/ufs/host/ufs-qcom.c
index ab5aed241913..5ef810b95b72 100644
--- a/drivers/ufs/host/ufs-qcom.c
+++ b/drivers/ufs/host/ufs-qcom.c
@@ -1962,7 +1962,7 @@ static void ufs_qcom_config_scaling_param(struct ufs_hba *hba,
 	p->polling_ms = 60;
 	p->timer = DEVFREQ_TIMER_DELAYED;
 	d->upthreshold = 70;
-	d->downdifferential = 5;
+	d->downdifferential = 65;

 	hba->clk_scaling.suspend_on_no_request = true;
 }
--
2.34.1


  parent reply	other threads:[~2026-01-22 14:13 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-01-22 14:13 [PATCH V1 0/3] ufs: ufs-qcom: Fixes and optimizations for Qualcomm UFS platform Nitin Rawat
2026-01-22 14:13 ` [PATCH V1 1/3] ufs: ufs-qcom: Add UFS ESI CPU affinity support Nitin Rawat
2026-01-23  0:57   ` Bart Van Assche
2026-01-22 14:13 ` [PATCH V1 2/3] ufs: ufs-qcom: Align programming sequence for UFS controller v6.2 Nitin Rawat
2026-01-22 15:09   ` Konrad Dybcio
2026-08-26  5:27     ` Nitin Rawat
2026-01-22 14:13 ` Nitin Rawat [this message]
2026-01-22 15:11   ` [PATCH V1 3/3] ufs: ufs-qcom: Fix sequential read variance Konrad Dybcio

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