From: Cristian Marussi <cristian.marussi@arm.com>
Date: Fri, 8 May 2026 15:32:46 +0000 (+0100)
Subject: clk: scmi: Fix clock rate rounding
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d0c81a38d06d446d341532700b3a4a43d3b00eb1;p=thirdparty%2Fkernel%2Flinux.git

clk: scmi: Fix clock rate rounding

While the do_div() helper used for rounding expects its divisor argument
to be a 32bits quantity, the currently provided divisor parameter is a
64bit value that, as a consequence, is silently truncated and a possible
source of bugs.

Fix by using the proper div64_ul helper.

Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: linux-clk@vger.kernel.org
Fixes: 7a8655e19bdb ("clk: scmi: Fix the rounding of clock rate")
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Tested-by: Florian Fainelli <florian.fainelli@broadcom.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://patch.msgid.link/20260508153300.2224715-2-cristian.marussi@arm.com
Reviewed-by: Brian Masney <bmasney@redhat.com>
Signed-off-by: Sudeep Holla <sudeep.holla@kernel.org>
---

diff --git a/drivers/clk/clk-scmi.c b/drivers/clk/clk-scmi.c
index 6b286ea6f1218..b6a12f3bc123c 100644
--- a/drivers/clk/clk-scmi.c
+++ b/drivers/clk/clk-scmi.c
@@ -10,9 +10,9 @@
 #include <linux/device.h>
 #include <linux/err.h>
 #include <linux/of.h>
+#include <linux/math64.h>
 #include <linux/module.h>
 #include <linux/scmi_protocol.h>
-#include <asm/div64.h>
 
 #define NOT_ATOMIC	false
 #define ATOMIC		true
@@ -83,7 +83,7 @@ static int scmi_clk_determine_rate(struct clk_hw *hw,
 
 	ftmp = req->rate - fmin;
 	ftmp += clk->info->range.step_size - 1; /* to round up */
-	do_div(ftmp, clk->info->range.step_size);
+	ftmp = div64_ul(ftmp, clk->info->range.step_size);
 
 	req->rate = ftmp * clk->info->range.step_size + fmin;