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From: Junhui Liu <junhui.liu@pigmoral.tech>
To: Michael Turquette <mturquette@baylibre.com>,
	 Stephen Boyd <sboyd@kernel.org>, Rob Herring <robh@kernel.org>,
	 Krzysztof Kozlowski <krzk+dt@kernel.org>,
	 Conor Dooley <conor+dt@kernel.org>,
	Junhui Liu <junhui.liu@pigmoral.tech>,
	 Philipp Zabel <p.zabel@pengutronix.de>,
	 Paul Walmsley <paul.walmsley@sifive.com>,
	 Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>,
	 Alexandre Ghiti <alex@ghiti.fr>
Cc: linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org,
	 devicetree@vger.kernel.org, linux-riscv@lists.infradead.org,
	 "fushan.zeng" <fushan.zeng@anlogic.com>
Subject: [PATCH 1/5] clk: correct clk_div_mask() return value for width == 32
Date: Mon, 22 Sep 2025 22:51:47 +0800	[thread overview]
Message-ID: <20250922-dr1v90-cru-v1-1-e393d758de4e@pigmoral.tech> (raw)
In-Reply-To: <20250922-dr1v90-cru-v1-0-e393d758de4e@pigmoral.tech>

The macro clk_div_mask() currently wraps to zero when width is 32 due to
1 << 32 being undefined behavior. This leads to incorrect mask generation
and prevents correct retrieval of register field values for 32-bit-wide
dividers.

Although it is unlikely to exhaust all U32_MAX div, some clock IPs may rely
on a 32-bit val entry in their div_table to match a div, so providing a
full 32-bit mask is necessary.

Fix this by casting 1 to long, ensuring proper behavior for valid widths up
to 32.

Signed-off-by: Junhui Liu <junhui.liu@pigmoral.tech>
---
 include/linux/clk-provider.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index 630705a47129453c241f1b1755f2c2f2a7ed8f77..a651ccaf1b44ff905c2bd4b9a7043f9e2169d27f 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -720,7 +720,7 @@ struct clk_divider {
 	spinlock_t	*lock;
 };
 
-#define clk_div_mask(width)	((1 << (width)) - 1)
+#define clk_div_mask(width)	((1L << (width)) - 1)
 #define to_clk_divider(_hw) container_of(_hw, struct clk_divider, hw)
 
 #define CLK_DIVIDER_ONE_BASED		BIT(0)

-- 
2.51.0


  reply	other threads:[~2025-09-22 14:54 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-09-22 14:51 [PATCH 0/5] clk/reset: anlogic: add support for DR1V90 SoC Junhui Liu
2025-09-22 14:51 ` Junhui Liu [this message]
2025-09-23  3:06   ` [PATCH 1/5] clk: correct clk_div_mask() return value for width == 32 Troy Mitchell
2025-09-22 14:51 ` [PATCH 2/5] dt-bindings: clock: add Anlogic DR1V90 CRU Junhui Liu
2025-09-23 19:02   ` Conor Dooley
2025-09-22 14:51 ` [PATCH 3/5] clk: anlogic: add cru support for Anlogic DR1V90 SoC Junhui Liu
2025-09-22 14:51 ` [PATCH 4/5] reset: anlogic: add support for Anlogic DR1V90 resets Junhui Liu
2025-09-22 14:51 ` [PATCH 5/5] riscv: dts: anlogic: add clocks and CRU for DR1V90 Junhui Liu

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