From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thierry Reding Subject: Re: [PATCH] mmc: tegra: Disable UHS-I modes for tegra124 Date: Wed, 13 Apr 2016 17:24:40 +0200 Message-ID: <20160413152440.GD29509@ulmo.ba.sec> References: <1460558156-10407-1-git-send-email-jonathanh@nvidia.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="SFyWQ0h3ruR435lw" Return-path: Content-Disposition: inline In-Reply-To: <1460558156-10407-1-git-send-email-jonathanh-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Jon Hunter Cc: Adrian Hunter , Ulf Hansson , Stephen Warren , Alexandre Courbot , linux-mmc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Lucas Stach List-Id: linux-tegra@vger.kernel.org --SFyWQ0h3ruR435lw Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Apr 13, 2016 at 03:35:56PM +0100, Jon Hunter wrote: > Tegra124 has been randomly hanging during system suspend when entering > the Tegra LP1 low power state. The hang is caused by the tegra SDHCI > driver and linked to the UHS-I tuning sequence. Disabling the UHS-I > modes for Tegra124 prevents any hangs from occurring when entering > system suspend. >=20 > Unfortunately, the tuning sequence described in the public Tegra > documentation is incomplete and on inspection of the current tuning > sequence that has been implemented is also incomplete and may cause > problems. In the short-term it is safer to disable UHS-I modes for now > and fix later because it would be too large of a change to simply patch > now. Therefore, disable UHS-I modes for Tegra124. >=20 > Signed-off-by: Jon Hunter > --- >=20 > I previously brought up this issue in this thread [0], but there has > been no resolution and so I think that for v4.6 we need to disable this > for now. I also pointered out that there is a complete implementation > available in the v3.18 kernel used by chromeos products [1]. We do plan > to get better support for UHS-I modes for Tegra it is just a matter of > bandwidth at the moment :-( >=20 > [0] http://marc.info/?l=3Dlinux-tegra&m=3D145926947408663&w=3D2 > [1] https://chromium.googlesource.com/chromiumos/third_party/kernel/+/chr= omeos-3.10/drivers/mmc/host/sdhci-tegra.c >=20 > drivers/mmc/host/sdhci-tegra.c | 10 +--------- > 1 file changed, 1 insertion(+), 9 deletions(-) Other than a couple of cases of inconsistent capitalization (tegra vs. Tegra, the latter being correct, of course), this looks fine to me: Acked-by: Thierry Reding --SFyWQ0h3ruR435lw Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAABCAAGBQJXDmS4AAoJEN0jrNd/PrOhvgUP/2e4Qj2QbBsLOsCECPhIOYTy 8O/OmwgJ4IMVvDeEBdJx50PXvK9Pmc/1iGA8F45SjIrtn9AbVRJqWWTSkSLdcNII t5DXQzlBnolld1kEkc/caiW//7Bnu9prD3JR/ciETJ6PVThXgy15Cv/tTFN18AoZ UYhANotraa/PAoM5emUgyp/hTgXIC4R7dOOYRog9lkXB9GX1GlTSBsFMvnTJlrik X5h7Or3BDr6c0XUmEmwwGdWmIE32bk4CjZ+y+5zGtli2FLNEmrk1DQ+2Kg01kdHX gP+MXeLfYCkYXPQyt+Vr71z3a+XI02nBDmAItYQiPw2ewPxS4nbyXgbfsCGoPzmZ 79KoWj8k3nlljPhbBefIzY/jHAG80TWOgYOaM/rwQjD4Ootg6ist9BPlg6v5SqMU belT49f3wWQzeXo5knEgItITEc1lnzC2Gs8sjml4eqU3fowugV061Zir8s5EnJCZ lxiBD/KQ74uzMb+SBd6pVKyMDXo51AqRj1V+PCLTahviZk1cs1b28KDOT7B3C8Os +57bkcVHQbOYq9suvjt29bDa4HE27F2POmF2Wja5zlsX8Fy5hwSISt7uTR1rfJ47 PQ8ChvXH3C9JRJ3uRxQoFN7RGeedwqBWFO2LnGEP6DaBFcMEniVaQuo3IG7wIAHI hkCK9ck/biUv83cLz4pi =DEpY -----END PGP SIGNATURE----- --SFyWQ0h3ruR435lw--