Hi Boris,
Am Freitag, 17. April 2015, 09:29:28 schrieb Boris Brezillon:
Clock rates are stored in an unsigned long field, but ->round_rate()
(which returns a rounded rate from a requested one) returns a long
value (errors are reported using negative error codes), which can lead
to long overflow if the clock rate exceed 2Ghz.
Change ->round_rate() prototype to return 0 or an error code, and pass the
requested rate as a pointer so that it can be adjusted depending on
hardware capabilities.
Signed-off-by: Boris Brezillon <redacted>
---
On a rk3288-veyron-pinky with the fix described below:
Tested-by: Heiko Stuebner <heiko@sntech.de>
quoted hunk ↗ jump to hunk
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index fa5a00e..1462ddc 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -1640,8 +1643,10 @@ static struct clk_core *clk_calc_new_rates(struct
clk_core *clk, &parent_hw);
parent = parent_hw ? parent_hw->core : NULL;
} else if (clk->ops->round_rate) {
- new_rate = clk->ops->round_rate(clk->hw, rate,
- &best_parent_rate);
+ if (clk->ops->round_rate(clk->hw, &new_rate,
+ &best_parent_rate))
+ return NULL;
+
if (new_rate < min_rate || new_rate > max_rate)
return NULL;
} else if (!parent || !(clk->flags & CLK_SET_RATE_PARENT)) {
This is using new_rate uninitialized when calling into the round_rate
callback. Which in turn pushed my PLLs up to 2.2GHz :-)
I guess you'll need something like the following:
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index db4e4b2..afc7733 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -1605,6 +1605,7 @@ static struct clk_core *clk_calc_new_rates(struct clk_core *clk,
&parent_hw);
parent = parent_hw ? parent_hw->core : NULL;
} else if (clk->ops->round_rate) {
+ new_rate = rate;
if (clk->ops->round_rate(clk->hw, &new_rate,
&best_parent_rate))
return NULL;
quoted hunk ↗ jump to hunk
diff --git a/drivers/clk/rockchip/clk-pll.c b/drivers/clk/rockchip/clk-pll.c
index f8d3baf..bd408ef 100644
--- a/drivers/clk/rockchip/clk-pll.c
+++ b/drivers/clk/rockchip/clk-pll.c
@@ -63,8 +63,8 @@ static const struct rockchip_pll_rate_table
*rockchip_get_pll_settings( return NULL;
}
-static long rockchip_pll_round_rate(struct clk_hw *hw,
- unsigned long drate, unsigned long *prate)
+static int rockchip_pll_round_rate(struct clk_hw *hw,
+ unsigned long *drate, unsigned long *prate)
{
struct rockchip_clk_pll *pll = to_rockchip_clk_pll(hw);
const struct rockchip_pll_rate_table *rate_table = pll->rate_table;@@ -72,12 +72,15 @@ static long rockchip_pll_round_rate(struct clk_hw *hw,
/* Assumming rate_table is in descending order */
for (i = 0; i < pll->rate_count; i++) {
- if (drate >= rate_table[i].rate)
- return rate_table[i].rate;
+ if (*drate >= rate_table[i].rate) {
+ *drate = rate_table[i].rate;
+ return 0;
+ }
}
/* return minimum supported value */
- return rate_table[i - 1].rate;
+ *drate = rate_table[i - 1].rate;
+ return 0;
}
/*
The rockchip-part:
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
And as I've stumbled onto this recently too, the clock-maintainership has
expanded to Stephen Boyd and linux-clk at vger.kernel.org .
Heiko