[PATCH 00/10] clk: implement clock rate protection mechanism
Jerome Brunet
jbrunet at baylibre.com
Thu May 18 09:37:54 PDT 2017
This Patchset is related the RFC [0] and the discussion around
CLK_SET_RATE_GATE available here [1]
The goal of this patchset is to provide a way for consumers to inform the
system that they depend on the rate of the clock source and can't tolerate
other consumers changing the rate or causing glitches.
With this series there is 3 use-case:
- the provider is not protected: nothing changes
- the provider is protected by only 1 consumer (and only once), then only
this consumer will be able to alter the rate of the clock, as it is the only
one depending on it.
- If the provider is protected more than once, or by the provider itself, the rate
is basically locked.
Changes since RFC:
- s/clk_protect/clk_rate_protect
- Request rework around core_nolock function
- Add clk_set_rate_protect
- Reword clk_rate_protect and clk_unprotect documentation
- Add few comments to explain the code
- Add 2 last patches to fix users of CLK_SET_RATE_GATE
The last 2 patches provide the same functionnality for providers themself by
fixing the issue with CLK_SET_RATE_GATE.
This was tested with the audio use case mentioned in [1]
[0]: http://lkml.kernel.org/r/20170321183330.26722-1-jbrunet@baylibre.com
[1]: http://lkml.kernel.org/r/148942423440.82235.17188153691656009029@resonance
Jerome Brunet (10):
clk: take the prepare lock out of clk_core_set_parent
clk: add clk_core_set_phase_nolock function
clk: rework calls to round and determine rate callbacks
clk: add support for clock protection
clk: add clk_set_rate_protect
clk: rollback set_rate_range changes on failure
clk: cosmetic changes to clk_summary debugfs entry
clk: fix incorrect usage of ENOSYS
clk: fix CLK_SET_RATE_GATE with clock rate protection
clk: move CLK_SET_RATE_GATE protection from prepare to enable
drivers/clk/clk.c | 397 +++++++++++++++++++++++++++++++++++--------
include/linux/clk-provider.h | 1 +
include/linux/clk.h | 43 +++++
3 files changed, 373 insertions(+), 68 deletions(-)
--
2.9.4
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