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author | Stefan Agner <stefan.agner@toradex.com> | 2017-03-03 19:25:22 -0800 |
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committer | Marcel Ziswiler <marcel.ziswiler@toradex.com> | 2017-04-03 15:36:21 +0200 |
commit | 9e05354060550645ad21a0455468e142c7fdb201 (patch) | |
tree | cd5d2de43bf4aff4aa88bdc7155963c71f3de3a0 /kernel/up.c | |
parent | 70f901b01c4ac4dfe741f91b76967a433674a37d (diff) |
ARM: imx: busfreq: do not force high frequency during suspend
If the M4 core is running and in a low frequency mode, the A7 core
should make sure that the AXI bus is left in a low frequency mode
when entering suspend.
So far the code unconditionally increased the high frequency variable
which essentially forced the AXI bus to run in high frequency mode
when entering suspend. With this change we leave the system in the
state it was last in and also make sure that the last state change
is actually applied before going to sleep. Typically high_bus_count
ends up to be 0 because all devices requiring a high bus frequency
release the bus during suspend, allowing the AXI bus to switch to
24MHz only.
If the M4 is not running we don't want to artificially slow down the
suspend process, hence let the bus run at full speed (it will get
disabled anyway by hardware mechanism). Similar, when the M4 is
running at high speed we likely need the bus capacity.
Signed-off-by: Stefan Agner <stefan.agner@toradex.com>
Acked-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Diffstat (limited to 'kernel/up.c')
0 files changed, 0 insertions, 0 deletions