Hi all, This series fixes a probe order issue with the Tegra EHCI driver. Basically, the register area of the 1st USB controller contains some registers that are global to all of the controllers, but that are also cleared when reset is asserted to the 1st controller. So if (say) the 3rd controller would be the first one to finish probing successfully, then the reset that happens during the 1st controller's probe would result in broken USB. So the before doing anything with the USB HW, we should reset the 1st controller once, and then never ever reset it again. However, fixing this without breaking existing device trees is very complicated, as the 2nd and 3rd Tegra EHCI controllers don't have a phandle to the 1st controller's reset handle, so we have to find it the hard way. This is done in patch 2. Patch 1 is a prerequisite change to the reset control API, so that we can get a reset controller reference without a struct device *. While testing that the 1st USB controller still works without a reset when the driver is unbound and bound again, I discovered an unbalanced regulator_disable + clk_disable_unprepare in the PHY code if the EHCI driver is unbound and rebound. This is fixed in patch 3. Tested on the Jetson TK1 that the 3rd USB port still works when the 1st controller is enabled and moved so that it's the last USB node in the DT. Also tested that the 1st controller still works after an unbind + rebind, even though it's not getting resetted during the probe. Thanks, Tuomas Tuomas Tynkkynen (3): reset: Re-export of_reset_control_get USB: EHCI: tegra: Fix probe order issue leading to broken USB USB: PHY: tegra: Call tegra_usb_phy_close only on device removal drivers/usb/host/ehci-tegra.c | 111 ++++++++++++++++++++++++++++++++++++++-- drivers/usb/phy/phy-tegra-usb.c | 8 ++- include/linux/reset.h | 8 +++ 3 files changed, 119 insertions(+), 8 deletions(-) -- 1.8.1.5 -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
