Patch "drivers: clk: zynqmp: update divider round rate logic" has been added to the 6.7-stable tree

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



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;
 }




[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Index of Archives]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux