Linux SCSI subsystem development
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From: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
To: Nitin Rawat <nitin.rawat@oss.qualcomm.com>,
	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
Subject: Re: [PATCH V1 3/3] ufs: ufs-qcom: Fix sequential read variance
Date: Thu, 22 Jan 2026 16:11:31 +0100	[thread overview]
Message-ID: <4aad22c3-a720-4d88-baa5-aead6854a771@oss.qualcomm.com> (raw)
In-Reply-To: <20260122141331.239354-4-nitin.rawat@oss.qualcomm.com>

On 1/22/26 3:13 PM, Nitin Rawat wrote:
> 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;

FWIW I see this is the value that's been shipping on android for 
quite a while 

Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>

Konrad


      reply	other threads:[~2026-01-22 15:11 UTC|newest]

Thread overview: 7+ 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
2026-01-22 14:13 ` [PATCH V1 3/3] ufs: ufs-qcom: Fix sequential read variance Nitin Rawat
2026-01-22 15:11   ` Konrad Dybcio [this message]

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