top_dclk is the DDR bus clock. If it is gated by clk_disable_unused,
all memory-mapped bus transactions cease to function, causing DMA
engines to hang and general system instability.

Mark it CLK_IS_CRITICAL so the CCF never gates it during the
unused clock sweep.

Fixes: e371a77255b8 ("clk: spacemit: k3: add the clock tree")
Signed-off-by: Troy Mitchell <troy.mitchell@linux.spacemit.com>
---
 drivers/clk/spacemit/ccu-k3.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/clk/spacemit/ccu-k3.c b/drivers/clk/spacemit/ccu-k3.c
index e98afd59f05c..bb8b75bdbdb3 100644
--- a/drivers/clk/spacemit/ccu-k3.c
+++ b/drivers/clk/spacemit/ccu-k3.c
@@ -846,7 +846,7 @@ static const struct clk_parent_data top_parents[] = {
 	CCU_PARENT_HW(pll6_d3),
 };
 CCU_MUX_DIV_GATE_FC_DEFINE(top_dclk, top_parents, APMU_TOP_DCLK_CTRL, 5, 3,
-			   BIT(8), 2, 3, BIT(1), 0);
+			   BIT(8), 2, 3, BIT(1), CLK_IS_CRITICAL);
 
 static const struct clk_parent_data ucie_parents[] = {
 	CCU_PARENT_HW(pll1_d8_307p2),

-- 
2.53.0

On Tue, Mar 31, 2026 at 04:27:07PM +0800, Troy Mitchell wrote:
> top_dclk is the DDR bus clock. If it is gated by clk_disable_unused,
> all memory-mapped bus transactions cease to function, causing DMA
> engines to hang and general system instability.
> 
> Mark it CLK_IS_CRITICAL so the CCF never gates it during the
> unused clock sweep.
> 
> Fixes: e371a77255b8 ("clk: spacemit: k3: add the clock tree")
> Signed-off-by: Troy Mitchell <troy.mitchell@linux.spacemit.com>

Reviewed-by: Brian Masney <bmasney@redhat.com>