diff options
author | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2016-11-01 14:27:38 -0300 |
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committer | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2016-11-01 14:27:38 -0300 |
commit | 1eae9639aac0f8de4d284f567ec722a822b52513 (patch) | |
tree | 34e45a5c5e6a1033a444bea952ba9199e57f3a19 /drivers/clk/bcm | |
parent | 037d32aa8f748e39844d2a5b607fb063b4583843 (diff) |
Linux-libre 4.8.6-gnupck-4.8.6-gnu
Diffstat (limited to 'drivers/clk/bcm')
-rw-r--r-- | drivers/clk/bcm/clk-bcm2835.c | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/drivers/clk/bcm/clk-bcm2835.c b/drivers/clk/bcm/clk-bcm2835.c index 7a7970865..0fc71cbaa 100644 --- a/drivers/clk/bcm/clk-bcm2835.c +++ b/drivers/clk/bcm/clk-bcm2835.c @@ -1006,16 +1006,28 @@ static int bcm2835_clock_set_rate(struct clk_hw *hw, return 0; } +static bool +bcm2835_clk_is_pllc(struct clk_hw *hw) +{ + if (!hw) + return false; + + return strncmp(clk_hw_get_name(hw), "pllc", 4) == 0; +} + static int bcm2835_clock_determine_rate(struct clk_hw *hw, struct clk_rate_request *req) { struct bcm2835_clock *clock = bcm2835_clock_from_hw(hw); struct clk_hw *parent, *best_parent = NULL; + bool current_parent_is_pllc; unsigned long rate, best_rate = 0; unsigned long prate, best_prate = 0; size_t i; u32 div; + current_parent_is_pllc = bcm2835_clk_is_pllc(clk_hw_get_parent(hw)); + /* * Select parent clock that results in the closest but lower rate */ @@ -1023,6 +1035,17 @@ static int bcm2835_clock_determine_rate(struct clk_hw *hw, parent = clk_hw_get_parent_by_index(hw, i); if (!parent) continue; + + /* + * Don't choose a PLLC-derived clock as our parent + * unless it had been manually set that way. PLLC's + * frequency gets adjusted by the firmware due to + * over-temp or under-voltage conditions, without + * prior notification to our clock consumer. + */ + if (bcm2835_clk_is_pllc(parent) && !current_parent_is_pllc) + continue; + prate = clk_hw_get_rate(parent); div = bcm2835_clock_choose_div(hw, req->rate, prate, true); rate = bcm2835_clock_rate_from_divisor(clock, prate, div); |