From: "Alim Akhtar" <alim.akhtar@samsung.com>
To: "'Avri Altman'" <Avri.Altman@wdc.com>, <robh+dt@kernel.org>,
<devicetree@vger.kernel.org>, <linux-scsi@vger.kernel.org>
Cc: <krzk@kernel.org>, <martin.petersen@oracle.com>,
<kwmad.kim@samsung.com>, <stanley.chu@mediatek.com>,
<cang@codeaurora.org>, <linux-samsung-soc@vger.kernel.org>,
<linux-arm-kernel@lists.infradead.org>,
<linux-kernel@vger.kernel.org>
Subject: RE: [PATCH v4 4/5] scsi: ufs-exynos: add UFS host support for Exynos SoCs
Date: Thu, 2 Apr 2020 20:38:15 +0530 [thread overview]
Message-ID: <000001d60900$8b6f5e70$a24e1b50$@samsung.com> (raw)
In-Reply-To: <SN6PR04MB4640B92BC9EA5CFEB74BE5EAFCCD0@SN6PR04MB4640.namprd04.prod.outlook.com>
Hi Avri
> -----Original Message-----
> From: Avri Altman <Avri.Altman@wdc.com>
> Sent: 28 March 2020 16:58
> To: Alim Akhtar <alim.akhtar@samsung.com>; robh+dt@kernel.org;
> devicetree@vger.kernel.org; linux-scsi@vger.kernel.org
> Cc: krzk@kernel.org; martin.petersen@oracle.com; kwmad.kim@samsung.com;
> stanley.chu@mediatek.com; cang@codeaurora.org; linux-samsung-
> soc@vger.kernel.org; linux-arm-kernel@lists.infradead.org; linux-
> kernel@vger.kernel.org
> Subject: RE: [PATCH v4 4/5] scsi: ufs-exynos: add UFS host support for Exynos
> SoCs
>
> Hi,
>
> > +
> > +long exynos_ufs_calc_time_cntr(struct exynos_ufs *ufs, long period) {
> > + const int precise = 10;
> > + long pclk_rate = ufs->pclk_rate;
> > + long clk_period, fraction;
> > +
> > + clk_period = UNIPRO_PCLK_PERIOD(ufs);
> > + fraction = ((NSEC_PER_SEC % pclk_rate) * precise) / pclk_rate;
> > +
> > + return (period * precise) / ((clk_period * precise) +
> > +fraction); }
> This helper essentially calculates a factor f, and returns period x f.
> Why not do that regardless of period?
>
The period can be different for different timing attributes, so this helper function takes the period and returns the timer counter value based on the pclk_rate.
> > +extern long exynos_ufs_calc_time_cntr(struct exynos_ufs *, long);
> Why this factor needed to be exported?
Yes, not needed, will correct this in next version, which I am planning to post soon.
Thanks for your time and review, let me know if you have more inputs.
WARNING: multiple messages have this Message-ID (diff)
From: "Alim Akhtar" <alim.akhtar@samsung.com>
To: "'Avri Altman'" <Avri.Altman@wdc.com>, <robh+dt@kernel.org>,
<devicetree@vger.kernel.org>, <linux-scsi@vger.kernel.org>
Cc: linux-samsung-soc@vger.kernel.org, martin.petersen@oracle.com,
linux-kernel@vger.kernel.org, krzk@kernel.org,
kwmad.kim@samsung.com, cang@codeaurora.org,
stanley.chu@mediatek.com, linux-arm-kernel@lists.infradead.org
Subject: RE: [PATCH v4 4/5] scsi: ufs-exynos: add UFS host support for Exynos SoCs
Date: Thu, 2 Apr 2020 20:38:15 +0530 [thread overview]
Message-ID: <000001d60900$8b6f5e70$a24e1b50$@samsung.com> (raw)
In-Reply-To: <SN6PR04MB4640B92BC9EA5CFEB74BE5EAFCCD0@SN6PR04MB4640.namprd04.prod.outlook.com>
Hi Avri
> -----Original Message-----
> From: Avri Altman <Avri.Altman@wdc.com>
> Sent: 28 March 2020 16:58
> To: Alim Akhtar <alim.akhtar@samsung.com>; robh+dt@kernel.org;
> devicetree@vger.kernel.org; linux-scsi@vger.kernel.org
> Cc: krzk@kernel.org; martin.petersen@oracle.com; kwmad.kim@samsung.com;
> stanley.chu@mediatek.com; cang@codeaurora.org; linux-samsung-
> soc@vger.kernel.org; linux-arm-kernel@lists.infradead.org; linux-
> kernel@vger.kernel.org
> Subject: RE: [PATCH v4 4/5] scsi: ufs-exynos: add UFS host support for Exynos
> SoCs
>
> Hi,
>
> > +
> > +long exynos_ufs_calc_time_cntr(struct exynos_ufs *ufs, long period) {
> > + const int precise = 10;
> > + long pclk_rate = ufs->pclk_rate;
> > + long clk_period, fraction;
> > +
> > + clk_period = UNIPRO_PCLK_PERIOD(ufs);
> > + fraction = ((NSEC_PER_SEC % pclk_rate) * precise) / pclk_rate;
> > +
> > + return (period * precise) / ((clk_period * precise) +
> > +fraction); }
> This helper essentially calculates a factor f, and returns period x f.
> Why not do that regardless of period?
>
The period can be different for different timing attributes, so this helper function takes the period and returns the timer counter value based on the pclk_rate.
> > +extern long exynos_ufs_calc_time_cntr(struct exynos_ufs *, long);
> Why this factor needed to be exported?
Yes, not needed, will correct this in next version, which I am planning to post soon.
Thanks for your time and review, let me know if you have more inputs.
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2020-04-02 15:08 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20200327171411epcas5p17f4457f9fd61800257607059b9506fb2@epcas5p1.samsung.com>
2020-03-27 17:06 ` [PATCH v4 0/5] exynos-ufs: Add support for UFS HCI Alim Akhtar
2020-03-27 17:06 ` Alim Akhtar
[not found] ` <CGME20200327171414epcas5p1460e932c0bc98f31ebdd115218b4fd49@epcas5p1.samsung.com>
2020-03-27 17:06 ` [PATCH v4 1/5] dt-bindings: phy: Document Samsung UFS PHY bindings Alim Akhtar
2020-03-27 17:06 ` Alim Akhtar
2020-04-05 1:54 ` Rob Herring
2020-04-05 1:54 ` Rob Herring
2020-04-07 0:28 ` Alim Akhtar
2020-04-07 0:28 ` Alim Akhtar
[not found] ` <CGME20200327171416epcas5p43133a28159ef24b145fcc8f3df102dde@epcas5p4.samsung.com>
2020-03-27 17:06 ` [PATCH v4 2/5] phy: samsung-ufs: add UFS PHY driver for samsung SoC Alim Akhtar
2020-03-27 17:06 ` Alim Akhtar
[not found] ` <CGME20200327171418epcas5p4b85bea273e17c05a7edca58f528c435a@epcas5p4.samsung.com>
2020-03-27 17:06 ` [PATCH v4 3/5] Documentation: devicetree: ufs: Add DT bindings for exynos UFS host controller Alim Akhtar
2020-03-27 17:06 ` Alim Akhtar
2020-04-05 2:02 ` Rob Herring
2020-04-05 2:02 ` Rob Herring
2020-04-12 5:41 ` Alim Akhtar
2020-04-12 5:41 ` Alim Akhtar
[not found] ` <CGME20200327171420epcas5p490e1e6d090a540eaf050e0728a39ba25@epcas5p4.samsung.com>
2020-03-27 17:06 ` [PATCH v4 4/5] scsi: ufs-exynos: add UFS host support for Exynos SoCs Alim Akhtar
2020-03-27 17:06 ` Alim Akhtar
2020-03-28 11:28 ` Avri Altman
2020-03-28 11:28 ` Avri Altman
2020-04-02 15:08 ` Alim Akhtar [this message]
2020-04-02 15:08 ` Alim Akhtar
[not found] ` <CGME20200327171423epcas5p485d227f19e45999ad9b42b21d2864e4a@epcas5p4.samsung.com>
2020-03-27 17:06 ` [PATCH v4 5/5] arm64: dts: Add node for ufs exynos7 Alim Akhtar
2020-03-27 17:06 ` Alim Akhtar
2020-03-28 13:30 ` Paweł Chmiel
2020-03-28 13:30 ` Paweł Chmiel
2020-03-28 15:35 ` Alim Akhtar
2020-03-28 15:35 ` Alim Akhtar
2020-03-28 17:46 ` Paweł Chmiel
2020-03-28 17:46 ` Paweł Chmiel
2020-03-29 15:35 ` Alim Akhtar
2020-03-29 15:35 ` Alim Akhtar
2020-04-03 16:52 ` Paweł Chmiel
2020-04-03 16:52 ` Paweł Chmiel
2020-04-04 18:15 ` Alim Akhtar
2020-04-04 18:15 ` Alim Akhtar
2020-04-04 19:33 ` Paweł Chmiel
2020-04-04 19:33 ` Paweł Chmiel
2020-04-04 20:25 ` Paweł Chmiel
2020-04-04 20:25 ` Paweł Chmiel
2020-04-05 1:48 ` Alim Akhtar
2020-04-05 1:48 ` Alim Akhtar
2020-04-05 8:11 ` Paweł Chmiel
2020-04-05 8:11 ` Paweł Chmiel
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