linux-kernel - [PATCH] clk: sunxi-ng: a523: Mark MBUS clock as critical

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Message-Id: <20250607135029.2085140-1-wens@kernel.org>
Date: Sat,  7 Jun 2025 21:50:29 +0800
From: Chen-Yu Tsai <wens@...nel.org>
To: Stephen Boyd <sboyd@...nel.org>,
	Jernej Skrabec <jernej.skrabec@...il.com>,
	Samuel Holland <samuel@...lland.org>
Cc: Chen-Yu Tsai <wens@...e.org>,
	linux-clk@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org,
	linux-sunxi@...ts.linux.dev,
	linux-kernel@...r.kernel.org,
	Andre Przywara <andre.przywara@....com>
Subject: [PATCH] clk: sunxi-ng: a523: Mark MBUS clock as critical

From: Chen-Yu Tsai <wens@...e.org>

The MBUS serves as the main data bus for various DMA masters in the
system. If its clock is not enabled, the DMA operations will stall,
leading to the peripherals stalling or timing out. This has been
observed as USB or MMC hosts timing out waiting for transactions
when the clock is automatically disabled by the CCF due to it not
being used.

Mark the clock as critical so that it never gets disabled.

Fixes: 74b0443a0d0a ("clk: sunxi-ng: a523: add system mod clocks")
Signed-off-by: Chen-Yu Tsai <wens@...e.org>
---
 drivers/clk/sunxi-ng/ccu-sun55i-a523.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/sunxi-ng/ccu-sun55i-a523.c b/drivers/clk/sunxi-ng/ccu-sun55i-a523.c
index 9efb9fd24b42..1a9a1cb869e2 100644
--- a/drivers/clk/sunxi-ng/ccu-sun55i-a523.c
+++ b/drivers/clk/sunxi-ng/ccu-sun55i-a523.c
@@ -385,7 +385,8 @@ static SUNXI_CCU_MP_DATA_WITH_MUX_GATE_FEAT(mbus_clk, "mbus", mbus_parents,
 					    0, 0,		/* no P */
 					    24, 3,	/* mux */
 					    BIT(31),	/* gate */
-					    0, CCU_FEATURE_UPDATE_BIT);
+					    CLK_IS_CRITICAL,
+					    CCU_FEATURE_UPDATE_BIT);
 
 static const struct clk_hw *mbus_hws[] = { &mbus_clk.common.hw };
 
-- 
2.39.5