| Message ID | 1377028813-32762-1-git-send-email-swarren@wwwdotorg.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Aug 20, 2013 at 02:00:13PM -0600, Stephen Warren wrote: > From: Stephen Warren <swarren@nvidia.com> > > This fixes a regression exposed during the merge window by commit > 9f310de "ARM: tegra: fix VBUS regulator GPIO polarity in DT"; namely that > USB VBUS doesn't get turned on, so USB devices are not detected. This > affects the internal USB port on TrimSlice (i.e. the USB->SATA bridge, to > which the SSD is connected) and the external port(s) on Seaboard/ > Springbank and Whistler. > > The Tegra DT as written in v3.11 allows two paths to enable USB VBUS: > > 1) Via the legacy DT binding for the USB controller; it can directly > acquire a VBUS GPIO and activate it. > > 2) Via a regulator for VBUS, which is referenced by the new DT binding > for the USB controller. > > Those two methods both use the same GPIO, and hence whichever of the > USB controller and regulator gets probed first ends up owning the GPIO. > In practice, the USB driver only supports path (1) above, since the > patches to support the new USB binding are not present until v3.12:-( > > In practice, the regulator ends up being probed first and owning the > GPIO. Since nothing enables the regulator (the USB driver code is not > yet present), the regulator ends up being turned off. This originally > caused no problem, because the polarity in the regulator definition was > incorrect, so attempting to turn off the regulator actually turned it > on, and everything worked:-( > > However, when testing the new USB driver code in v3.12, I noticed the > incorrect polarity and fixed it in commit 9f310de "ARM: tegra: fix VBUS > regulator GPIO polarity in DT". In the context of v3.11, this patch then > caused the USB VBUS to actually turn off, which broke USB ports with VBUS > control. I got this patch included in v3.11-rc1 since it fixed a bug in > device tree (incorrect polarity specification), and hence was suitable to > be included early in the rc series. I evidently did not test the patch at > all, or correctly, in the context of v3.11, and hence did not notice the > issue that I have explained above:-( > > Fix this by making the USB VBUS regulators always enabled. This way, if > the regulator owns the GPIO, it will always be turned on, even if there > is no USB driver code to request the regulator be turned on. Even > ignoring this bug, this is a reasonable way to configure the HW anyway. > > If this patch is applied to v3.11, it will cause a couple pretty trivial > conflicts in tegra20-{trimslice,seaboard}.dts when creating v3.12, since > the context right above the added lines changed in patches destined for > v3.12. > > Reported-by: Kyle McMartin <kmcmarti@redhat.com> > Signed-off-by: Stephen Warren <swarren@nvidia.com> > --- > This is a patch for v3.11-rc* Applied, thanks. -Olof
diff --git a/arch/arm/boot/dts/tegra20-seaboard.dts b/arch/arm/boot/dts/tegra20-seaboard.dts index 365760b..40e6fb2 100644 --- a/arch/arm/boot/dts/tegra20-seaboard.dts +++ b/arch/arm/boot/dts/tegra20-seaboard.dts @@ -830,6 +830,8 @@ regulator-max-microvolt = <5000000>; enable-active-high; gpio = <&gpio 24 0>; /* PD0 */ + regulator-always-on; + regulator-boot-on; }; }; diff --git a/arch/arm/boot/dts/tegra20-trimslice.dts b/arch/arm/boot/dts/tegra20-trimslice.dts index ed4b901..37c93d3 100644 --- a/arch/arm/boot/dts/tegra20-trimslice.dts +++ b/arch/arm/boot/dts/tegra20-trimslice.dts @@ -412,6 +412,8 @@ regulator-max-microvolt = <5000000>; enable-active-high; gpio = <&gpio 170 0>; /* PV2 */ + regulator-always-on; + regulator-boot-on; }; }; diff --git a/arch/arm/boot/dts/tegra20-whistler.dts b/arch/arm/boot/dts/tegra20-whistler.dts index ab67c94..a3d0eba 100644 --- a/arch/arm/boot/dts/tegra20-whistler.dts +++ b/arch/arm/boot/dts/tegra20-whistler.dts @@ -588,6 +588,8 @@ regulator-max-microvolt = <5000000>; enable-active-high; gpio = <&tca6416 0 0>; /* GPIO_PMU0 */ + regulator-always-on; + regulator-boot-on; }; vbus3_reg: regulator@3 { @@ -598,6 +600,8 @@ regulator-max-microvolt = <5000000>; enable-active-high; gpio = <&tca6416 1 0>; /* GPIO_PMU1 */ + regulator-always-on; + regulator-boot-on; }; };