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authorScott Wood <oss@buserror.net>2016-10-17 13:42:23 -0500
committerStephen Boyd <sboyd@codeaurora.org>2016-11-01 17:26:15 -0700
commit7c1c5413a7bdf1c9adc8d979521f1b8286366aef (patch)
tree91e4786a854b7b2b1372d7e427436f2006e008b0 /drivers/clk
parentc7129375312732f006ba9054c12ae4d4097d5519 (diff)
clk: qoriq: Don't allow CPU clocks higher than starting value
The boot-time frequency of a CPU is considered its rated maximum, as we have no other source of such information. However, this was previously only used for chips with 80% restrictions on secondary PLLs. This usually wasn't a problem because most chips/configs boot with a divider of /1, with other dividers being used only for dynamic frequency reduction. However, at least one config (LS1021A at less than 1 GHz) uses a different divider for top speed. This was causing cpufreq to set a frequency beyond the chip's rated speed. This is fixed by applying a 100%-of-initial-speed limit to all CPU PLLs, similar to the existing 80% limit that only applied to some. Signed-off-by: Scott Wood <oss@buserror.net> Cc: stable@vger.kernel.org Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Diffstat (limited to 'drivers/clk')
-rw-r--r--drivers/clk/clk-qoriq.c13
1 files changed, 8 insertions, 5 deletions
diff --git a/drivers/clk/clk-qoriq.c b/drivers/clk/clk-qoriq.c
index 20b105584f82..80ae2a51452d 100644
--- a/drivers/clk/clk-qoriq.c
+++ b/drivers/clk/clk-qoriq.c
@@ -700,6 +700,7 @@ static struct clk * __init create_mux_common(struct clockgen *cg,
struct mux_hwclock *hwc,
const struct clk_ops *ops,
unsigned long min_rate,
+ unsigned long max_rate,
unsigned long pct80_rate,
const char *fmt, int idx)
{
@@ -728,6 +729,8 @@ static struct clk * __init create_mux_common(struct clockgen *cg,
continue;
if (rate < min_rate)
continue;
+ if (rate > max_rate)
+ continue;
parent_names[j] = div->name;
hwc->parent_to_clksel[j] = i;
@@ -759,7 +762,7 @@ static struct clk * __init create_one_cmux(struct clockgen *cg, int idx)
struct mux_hwclock *hwc;
const struct clockgen_pll_div *div;
unsigned long plat_rate, min_rate;
- u64 pct80_rate;
+ u64 max_rate, pct80_rate;
u32 clksel;
hwc = kzalloc(sizeof(*hwc), GFP_KERNEL);
@@ -787,8 +790,8 @@ static struct clk * __init create_one_cmux(struct clockgen *cg, int idx)
return NULL;
}
- pct80_rate = clk_get_rate(div->clk);
- pct80_rate *= 8;
+ max_rate = clk_get_rate(div->clk);
+ pct80_rate = max_rate * 8;
do_div(pct80_rate, 10);
plat_rate = clk_get_rate(cg->pll[PLATFORM_PLL].div[PLL_DIV1].clk);
@@ -798,7 +801,7 @@ static struct clk * __init create_one_cmux(struct clockgen *cg, int idx)
else
min_rate = plat_rate / 2;
- return create_mux_common(cg, hwc, &cmux_ops, min_rate,
+ return create_mux_common(cg, hwc, &cmux_ops, min_rate, max_rate,
pct80_rate, "cg-cmux%d", idx);
}
@@ -813,7 +816,7 @@ static struct clk * __init create_one_hwaccel(struct clockgen *cg, int idx)
hwc->reg = cg->regs + 0x20 * idx + 0x10;
hwc->info = cg->info.hwaccel[idx];
- return create_mux_common(cg, hwc, &hwaccel_ops, 0, 0,
+ return create_mux_common(cg, hwc, &hwaccel_ops, 0, ULONG_MAX, 0,
"cg-hwaccel%d", idx);
}