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authorThierry Reding <treding@nvidia.com>2016-05-26 17:23:29 +0200
committerSasha Levin <sasha.levin@oracle.com>2016-07-11 11:10:44 -0400
commit6ff31a41c427154cb6592d4c1cc13bc6cbe52183 (patch)
tree77ac2196d5e38d3318b57d488bb800adfe8c7b47 /Documentation
parent743b34f44934ace86c0995d452f3910578918a11 (diff)
usb: host: ehci-tegra: Grab the correct UTMI pads reset
[ Upstream commit f8a15a9650694feaa0dabf197b0c94d37cd3fb42 ] There are three EHCI controllers on Tegra SoCs, each with its own reset line. However, the first controller contains a set of UTMI configuration registers that are shared with its siblings. These registers will only be reset as part of the first controller's reset. For proper operation it must be ensured that the UTMI configuration registers are reset before any of the EHCI controllers are enabled, irrespective of the probe order. Commit a47cc24cd1e5 ("USB: EHCI: tegra: Fix probe order issue leading to broken USB") introduced code that ensures the first controller is always reset before setting up any of the controllers, and is never again reset afterwards. This code, however, grabs the wrong reset. Each EHCI controller has two reset controls attached: 1) the USB controller reset and 2) the UTMI pads reset (really the first controller's reset). In order to reset the UTMI pads registers the code must grab the second reset, but instead it grabbing the first. Fixes: a47cc24cd1e5 ("USB: EHCI: tegra: Fix probe order issue leading to broken USB") Acked-by: Jon Hunter <jonathanh@nvidia.com> Cc: stable@vger.kernel.org Signed-off-by: Thierry Reding <treding@nvidia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
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