This is a note to let you know that I've just added the patch titled
drivers: clk: zynqmp: update divider round rate logic
to the 6.7-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:
drivers-clk-zynqmp-update-divider-round-rate-logic.patch
and it can be found in the queue-6.7 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 62be2a80d553dcf481dddc658766021d1f16dcc2
Author: Jay Buddhabhatti <jay.buddhabhatti@xxxxxxx>
Date: Wed Nov 29 03:29:16 2023 -0800
drivers: clk: zynqmp: update divider round rate logic
[ Upstream commit 1fe15be1fb613534ecbac5f8c3f8744f757d237d ]
Currently zynqmp divider round rate is considering single parent and
calculating rate and parent rate accordingly. But if divider clock flag
is set to SET_RATE_PARENT then its not trying to traverse through all
parent rate and not selecting best parent rate from that. So use common
divider_round_rate() which is traversing through all clock parents and
its rate and calculating proper parent rate.
Fixes: 3fde0e16d016 ("drivers: clk: Add ZynqMP clock driver")
Signed-off-by: Jay Buddhabhatti <jay.buddhabhatti@xxxxxxx>
Link: https://lore.kernel.org/r/20231129112916.23125-3-jay.buddhabhatti@xxxxxxx
Signed-off-by: Stephen Boyd <sboyd@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/clk/zynqmp/divider.c b/drivers/clk/zynqmp/divider.c
index 33a3b2a22659..5a00487ae408 100644
--- a/drivers/clk/zynqmp/divider.c
+++ b/drivers/clk/zynqmp/divider.c
@@ -110,52 +110,6 @@ static unsigned long zynqmp_clk_divider_recalc_rate(struct clk_hw *hw,
return DIV_ROUND_UP_ULL(parent_rate, value);
}
-static void zynqmp_get_divider2_val(struct clk_hw *hw,
- unsigned long rate,
- struct zynqmp_clk_divider *divider,
- u32 *bestdiv)
-{
- int div1;
- int div2;
- long error = LONG_MAX;
- unsigned long div1_prate;
- struct clk_hw *div1_parent_hw;
- struct zynqmp_clk_divider *pdivider;
- struct clk_hw *div2_parent_hw = clk_hw_get_parent(hw);
-
- if (!div2_parent_hw)
- return;
-
- pdivider = to_zynqmp_clk_divider(div2_parent_hw);
- if (!pdivider)
- return;
-
- div1_parent_hw = clk_hw_get_parent(div2_parent_hw);
- if (!div1_parent_hw)
- return;
-
- div1_prate = clk_hw_get_rate(div1_parent_hw);
- *bestdiv = 1;
- for (div1 = 1; div1 <= pdivider->max_div;) {
- for (div2 = 1; div2 <= divider->max_div;) {
- long new_error = ((div1_prate / div1) / div2) - rate;
-
- if (abs(new_error) < abs(error)) {
- *bestdiv = div2;
- error = new_error;
- }
- if (divider->flags & CLK_DIVIDER_POWER_OF_TWO)
- div2 = div2 << 1;
- else
- div2++;
- }
- if (pdivider->flags & CLK_DIVIDER_POWER_OF_TWO)
- div1 = div1 << 1;
- else
- div1++;
- }
-}
-
/**
* zynqmp_clk_divider_round_rate() - Round rate of divider clock
* @hw: handle between common and hardware-specific interfaces
@@ -174,6 +128,7 @@ static long zynqmp_clk_divider_round_rate(struct clk_hw *hw,
u32 div_type = divider->div_type;
u32 bestdiv;
int ret;
+ u8 width;
/* if read only, just return current value */
if (divider->flags & CLK_DIVIDER_READ_ONLY) {
@@ -193,23 +148,12 @@ static long zynqmp_clk_divider_round_rate(struct clk_hw *hw,
return DIV_ROUND_UP_ULL((u64)*prate, bestdiv);
}
- bestdiv = zynqmp_divider_get_val(*prate, rate, divider->flags);
-
- /*
- * In case of two divisors, compute best divider values and return
- * divider2 value based on compute value. div1 will be automatically
- * set to optimum based on required total divider value.
- */
- if (div_type == TYPE_DIV2 &&
- (clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT)) {
- zynqmp_get_divider2_val(hw, rate, divider, &bestdiv);
- }
+ width = fls(divider->max_div);
- if ((clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT) && divider->is_frac)
- bestdiv = rate % *prate ? 1 : bestdiv;
+ rate = divider_round_rate(hw, rate, prate, NULL, width, divider->flags);
- bestdiv = min_t(u32, bestdiv, divider->max_div);
- *prate = rate * bestdiv;
+ if (divider->is_frac && (clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT) && (rate % *prate))
+ *prate = rate;
return rate;
}
