c45e66a6b9
The SW-initiated power gate toggling is dropped by PMC if there is contention with a HW-initiated toggling, i.e. when one of CPU cores is gated by cpuidle driver. Software should retry the toggling after 10 microseconds on Tegra20/30 SoCs, hence add the retrying. On Tegra114+ the toggling method was changed in hardware, the TOGGLE_START bit indicates whether PMC is busy or could accept the command to toggle, hence handle that bit properly. The problem pops up after enabling dynamic power gating of 3D hardware, where 3D power domain fails to turn on/off "randomly". The programming sequence and quirks are documented in TRMs, but PMC driver obliviously re-used the Tegra20 logic for Tegra30+, which strikes back now. The 10 microseconds and other timeouts aren't documented in TRM, they are taken from downstream kernel. Link: https://nv-tegra.nvidia.com/gitweb/?p=linux-2.6.git;a=commit;h=311dd1c318b70e93bcefec15456a10ff2b9eb0ff Link: https://nv-tegra.nvidia.com/gitweb/?p=linux-3.10.git;a=commit;h=7f36693c47cb23730a6b2822e0975be65fb0c51d Tested-by: Peter Geis <pgwipeout@gmail.com> # Ouya T30 Tested-by: Nicolas Chauvet <kwizart@gmail.com> # PAZ00 T20 and TK1 T124 Tested-by: Matt Merhar <mattmerhar@protonmail.com> # Ouya T30 Signed-off-by: Dmitry Osipenko <digetx@gmail.com> Signed-off-by: Thierry Reding <treding@nvidia.com> |
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| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
README
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.