From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thierry Reding Subject: Re: [PATCH 3/8] mmc: tegra: Implement HS400 enhanced strobe Date: Thu, 9 Aug 2018 13:43:45 +0200 Message-ID: <20180809114345.GL21639@ulmo> References: <1533650404-18125-1-git-send-email-avienamo@nvidia.com> <1533650404-18125-4-git-send-email-avienamo@nvidia.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="HBg0C3yr6HVa1ZCc" Return-path: Content-Disposition: inline In-Reply-To: <1533650404-18125-4-git-send-email-avienamo@nvidia.com> Sender: linux-kernel-owner@vger.kernel.org To: Aapo Vienamo Cc: Ulf Hansson , Rob Herring , Mark Rutland , Jonathan Hunter , Adrian Hunter , Mikko Perttunen , linux-mmc@vger.kernel.org, devicetree@vger.kernel.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-tegra@vger.kernel.org --HBg0C3yr6HVa1ZCc Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Aug 07, 2018 at 04:59:59PM +0300, Aapo Vienamo wrote: > Implement HS400 enhanced strobe. Can you provide a little more information about what the impact is of this? Does this increase throughput? How much? >=20 > Signed-off-by: Aapo Vienamo > --- > drivers/mmc/host/sdhci-tegra.c | 22 ++++++++++++++++++++++ > 1 file changed, 22 insertions(+) >=20 > diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegr= a.c > index 426f7ea..d81143b 100644 > --- a/drivers/mmc/host/sdhci-tegra.c > +++ b/drivers/mmc/host/sdhci-tegra.c > @@ -43,6 +43,9 @@ > #define SDHCI_CLOCK_CTRL_PADPIPE_CLKEN_OVERRIDE BIT(3) > #define SDHCI_CLOCK_CTRL_SPI_MODE_CLKEN_OVERRIDE BIT(2) > =20 > +#define SDHCI_TEGRA_VENDOR_SYS_SW_CTRL 0x104 > +#define SDHCI_TEGRA_SYS_SW_CTRL_ENHANCED_STROBE BIT(31) > + > #define SDHCI_TEGRA_VENDOR_CAP_OVERRIDES 0x10c > #define SDHCI_TEGRA_CAP_OVERRIDES_DQS_TRIM_MASK 0x00003f00 > #define SDHCI_TEGRA_CAP_OVERRIDES_DQS_TRIM_SHIFT 8 > @@ -271,6 +274,22 @@ static void tegra_sdhci_set_tap(struct sdhci_host *h= ost, unsigned int tap) > } > } > =20 > +static void tegra_sdhci_hs400_enhanced_strobe(struct mmc_host *mmc, > + struct mmc_ios *ios) > +{ > + struct sdhci_host *host =3D mmc_priv(mmc); > + u32 reg; > + > + reg =3D sdhci_readl(host, SDHCI_TEGRA_VENDOR_SYS_SW_CTRL); > + pr_err("enhanced strobe: %d\n", ios->enhanced_strobe); Left-over debug error? > + if (ios->enhanced_strobe) > + reg |=3D SDHCI_TEGRA_SYS_SW_CTRL_ENHANCED_STROBE; > + else > + reg &=3D ~SDHCI_TEGRA_SYS_SW_CTRL_ENHANCED_STROBE; > + sdhci_writel(host, reg, SDHCI_TEGRA_VENDOR_SYS_SW_CTRL); You might want to add blank lines around the if ... else ... block for readability. Thierry --HBg0C3yr6HVa1ZCc Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEEiOrDCAFJzPfAjcif3SOs138+s6EFAltsKPEACgkQ3SOs138+ s6Eb1RAAloFX6Tv2ZWx0XzekpM2KJlXdnj3HP5A+Eny4d69pJScQlCGD2eG8NRhJ /CZpDUSjuB2vz49uA80N0c1OeHFHch7hd5k+rKVeK/p7q1s/vi1mD9IgKIbo89gQ 5TvgFnW8gMsmD7rPci7RY5a2De2U6/KIt0WxSK01QyCodAizS3gtrUX4rfcDv74y V5MGe6gDTx6jXBu6X4WHf90fl9a2DcVXiSC8LkDuobYV0ukr6NEA32ogOW5+94e4 EqDoIj+V68+eRe/04Pcxg2CIGTwwCHhsFGQv53a09aPnaiS50AS62YqnhFnnoF1c dBn8cVaUP7bTGktb9jWd5mvmTCIsTWY8p4iIidQ/M4RW7+9uDAYFswdJtLvhTcLg f4zZxKqY8C/B5AibHjFCzJR77FHjmrpyjSo3C2Skg2zry3DxFRnwYD/5CbRbbLUj 5V0PqwbFHO78K1hn6hRS2aPmOp42OO4aaut4k+oCEaIm42KxlYTvM7P4TgkjxtkS qDuO/evqbDGKVece7a+Rk/MSRc/NGnJBmOS7RlXzYqkgB1ivXXhKq9EwqevPSyIa 0YhQzOOydXvP9t9F57P1SS2u94wgjpGcWVhAbRLyJuInz+B1Dnpi+HHiuZQ6vdHn hWr3iJvLi0yAUWrA4rKPYr9FfbgqGdYigdxqkK6QkslhJafBoUE= =qF0n -----END PGP SIGNATURE----- --HBg0C3yr6HVa1ZCc--