This is a note to let you know that I've just added the patch titled
clk: qoriq: Don't allow CPU clocks higher than starting value
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
clk-qoriq-don-t-allow-cpu-clocks-higher-than-starting-value.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 7c1c5413a7bdf1c9adc8d979521f1b8286366aef Mon Sep 17 00:00:00 2001
From: Scott Wood <oss@xxxxxxxxxxxx>
Date: Mon, 17 Oct 2016 13:42:23 -0500
Subject: clk: qoriq: Don't allow CPU clocks higher than starting value
From: Scott Wood <oss@xxxxxxxxxxxx>
commit 7c1c5413a7bdf1c9adc8d979521f1b8286366aef upstream.
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@xxxxxxxxxxxx>
Signed-off-by: Stephen Boyd <sboyd@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/clk/clk-qoriq.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)
--- a/drivers/clk/clk-qoriq.c
+++ b/drivers/clk/clk-qoriq.c
@@ -700,6 +700,7 @@ static struct clk * __init create_mux_co
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_co
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_cm
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_cm
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_cm
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_hw
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);
}
Patches currently in stable-queue which might be from oss@xxxxxxxxxxxx are
queue-4.4/clk-qoriq-don-t-allow-cpu-clocks-higher-than-starting-value.patch
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html