From: Chen-Yu Tsai <wens@kernel.org>
To: Rob Herring <robh@kernel.org>,
Krzysztof Kozlowski <krzk+dt@kernel.org>,
Conor Dooley <conor+dt@kernel.org>,
Stephen Boyd <sboyd@kernel.org>, Chen-Yu Tsai <wens@csie.org>,
Jernej Skrabec <jernej@kernel.org>,
Samuel Holland <samuel@sholland.org>
Cc: Andre Przywara <andre.przywara@arm.com>,
linux-sunxi@lists.linux.dev, linux-clk@vger.kernel.org,
linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: [PATCH 3/8] clk: sunxi-ng: mp: Fix dual-divider clock rate readback
Date: Sun, 31 Aug 2025 01:08:56 +0800 [thread overview]
Message-ID: <20250830170901.1996227-4-wens@kernel.org> (raw)
In-Reply-To: <20250830170901.1996227-1-wens@kernel.org>
From: Chen-Yu Tsai <wens@csie.org>
When dual-divider clock support was introduced, the P divider offset was
left out of the .recalc_rate readback function. This causes the clock
rate to become bogus or even zero (possibly due to the P divider being
1, leading to a divide-by-zero).
Fix this by incorporating the P divider offset into the calculation.
Fixes: 45717804b75e ("clk: sunxi-ng: mp: introduce dual-divider clock")
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
---
drivers/clk/sunxi-ng/ccu_mp.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/clk/sunxi-ng/ccu_mp.c b/drivers/clk/sunxi-ng/ccu_mp.c
index 354c981943b6..4221b1888b38 100644
--- a/drivers/clk/sunxi-ng/ccu_mp.c
+++ b/drivers/clk/sunxi-ng/ccu_mp.c
@@ -185,7 +185,7 @@ static unsigned long ccu_mp_recalc_rate(struct clk_hw *hw,
p &= (1 << cmp->p.width) - 1;
if (cmp->common.features & CCU_FEATURE_DUAL_DIV)
- rate = (parent_rate / p) / m;
+ rate = (parent_rate / (p + cmp->p.offset)) / m;
else
rate = (parent_rate >> p) / m;
--
2.39.5
next prev parent reply other threads:[~2025-08-30 17:31 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-08-30 17:08 [PATCH 0/8] arm64: allwinner: a523: Enable MCU PRCM and NPU Chen-Yu Tsai
2025-08-30 17:08 ` [PATCH 1/8] dt-bindings: clock: sun55i-a523-ccu: Add missing NPU module clock Chen-Yu Tsai
2025-09-01 21:29 ` Rob Herring (Arm)
2025-09-05 15:12 ` Andre Przywara
2025-08-30 17:08 ` [PATCH 2/8] dt-bindings: clock: sun55i-a523-ccu: Add A523 MCU CCU clock controller Chen-Yu Tsai
2025-09-01 21:31 ` Rob Herring (Arm)
2025-08-30 17:08 ` Chen-Yu Tsai [this message]
2025-09-05 15:12 ` [PATCH 3/8] clk: sunxi-ng: mp: Fix dual-divider clock rate readback Andre Przywara
2025-09-05 15:17 ` Chen-Yu Tsai
2025-08-30 17:08 ` [PATCH 4/8] clk: sunxi-ng: sun55i-a523-ccu: Add missing NPU module clock Chen-Yu Tsai
2025-09-05 15:14 ` Andre Przywara
2025-09-05 15:19 ` Chen-Yu Tsai
2025-08-30 17:08 ` [PATCH 5/8] clk: sunxi-ng: div: support power-of-two dividers Chen-Yu Tsai
2025-08-30 17:08 ` [PATCH 6/8] clk: sunxi-ng: add support for the A523/T527 MCU CCU Chen-Yu Tsai
2025-09-05 15:14 ` Andre Przywara
2025-09-05 16:13 ` Chen-Yu Tsai
2025-09-05 17:21 ` Andre Przywara
2025-08-30 17:09 ` [PATCH 7/8] arm64: dts: allwinner: a523: Add MCU PRCM CCU node Chen-Yu Tsai
2025-09-05 15:14 ` Andre Przywara
2025-08-30 17:09 ` [PATCH 8/8] arm64: dts: allwinner: a523: Add NPU device node Chen-Yu Tsai
2025-09-05 15:14 ` Andre Przywara
2025-09-10 15:46 ` (subset) [PATCH 0/8] arm64: allwinner: a523: Enable MCU PRCM and NPU Chen-Yu Tsai
2025-09-10 15:48 ` Chen-Yu Tsai
2025-09-11 8:32 ` Chen-Yu Tsai
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20250830170901.1996227-4-wens@kernel.org \
--to=wens@kernel.org \
--cc=andre.przywara@arm.com \
--cc=conor+dt@kernel.org \
--cc=devicetree@vger.kernel.org \
--cc=jernej@kernel.org \
--cc=krzk+dt@kernel.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-clk@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-sunxi@lists.linux.dev \
--cc=robh@kernel.org \
--cc=samuel@sholland.org \
--cc=sboyd@kernel.org \
--cc=wens@csie.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.