linux-kernel - Re: [PATCH V1 3/3] scsi: ufs: qcom: Add support to disable UFS LPM Feature

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <070f15425ba2535a0bb165d61243dc3e3f63d672.camel@mediatek.com>
Date: Wed, 23 Apr 2025 05:00:29 +0000
From: Peter Wang (王信友) <peter.wang@...iatek.com>
To: "avri.altman@....com" <avri.altman@....com>, "beanhuo@...ron.com"
	<beanhuo@...ron.com>, "quic_nitirawa@...cinc.com"
	<quic_nitirawa@...cinc.com>, "robh@...nel.org" <robh@...nel.org>,
	"bvanassche@....org" <bvanassche@....org>, "alim.akhtar@...sung.com"
	<alim.akhtar@...sung.com>, "krzk+dt@...nel.org" <krzk+dt@...nel.org>,
	"conor+dt@...nel.org" <conor+dt@...nel.org>, "mani@...nel.org"
	<mani@...nel.org>, "James.Bottomley@...senPartnership.com"
	<James.Bottomley@...senPartnership.com>, "martin.petersen@...cle.com"
	<martin.petersen@...cle.com>
CC: "linux-scsi@...r.kernel.org" <linux-scsi@...r.kernel.org>,
	"linux-arm-msm@...r.kernel.org" <linux-arm-msm@...r.kernel.org>,
	"devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH V1 3/3] scsi: ufs: qcom: Add support to disable UFS LPM
 Feature

On Thu, 2025-04-17 at 18:16 +0530, Nitin Rawat wrote:
> 
> External email : Please do not click links or open attachments until
> you have verified the sender or the content.
> 
> 
> There are emulation FPGA platforms or other platforms where UFS low
> power mode is either unsupported or power efficiency is not a
> critical
> requirement.
> 
> Disable all low power mode UFS feature based on the "disable-lpm"
> device
> tree property parsed in platform driver.
> 
> Signed-off-by: Nitin Rawat <quic_nitirawa@...cinc.com>
> ---
>  drivers/ufs/host/ufs-qcom.c | 15 ++++++++-------
>  1 file changed, 8 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/ufs/host/ufs-qcom.c b/drivers/ufs/host/ufs-
> qcom.c
> index 1b37449fbffc..1024edf36b68 100644
> --- a/drivers/ufs/host/ufs-qcom.c
> +++ b/drivers/ufs/host/ufs-qcom.c
> @@ -1014,13 +1014,14 @@ static void ufs_qcom_set_host_caps(struct
> ufs_hba *hba)
> 
>  static void ufs_qcom_set_caps(struct ufs_hba *hba)
>  {
> -       hba->caps |= UFSHCD_CAP_CLK_GATING |
> UFSHCD_CAP_HIBERN8_WITH_CLK_GATING;
> -       hba->caps |= UFSHCD_CAP_CLK_SCALING |
> UFSHCD_CAP_WB_WITH_CLK_SCALING;
> -       hba->caps |= UFSHCD_CAP_AUTO_BKOPS_SUSPEND;
> -       hba->caps |= UFSHCD_CAP_WB_EN;
> -       hba->caps |= UFSHCD_CAP_AGGR_POWER_COLLAPSE;
> -       hba->caps |= UFSHCD_CAP_RPM_AUTOSUSPEND;
> -
> +       if (!hba->disable_lpm) {
> +               hba->caps |= UFSHCD_CAP_CLK_GATING |
> UFSHCD_CAP_HIBERN8_WITH_CLK_GATING;
> +               hba->caps |= UFSHCD_CAP_CLK_SCALING |
> UFSHCD_CAP_WB_WITH_CLK_SCALING;
> +               hba->caps |= UFSHCD_CAP_AUTO_BKOPS_SUSPEND;
> +               hba->caps |= UFSHCD_CAP_WB_EN;
> 

Hi, Nitin,

If hba->disable_lpm is true, WB should enable?
Normally, you don't care about low power, so why wouldn't you enable
WB?

Thanks.
Peter



> +               hba->caps |= UFSHCD_CAP_AGGR_POWER_COLLAPSE;
> +               hba->caps |= UFSHCD_CAP_RPM_AUTOSUSPEND;
> +       }
>         ufs_qcom_set_host_caps(hba);
>  }
> 
> --
> 2.48.1
>