[PATCH] clk: sp7021: fix infrastructure clocks clobbering PLL provider entries

[Brian Masney]

Hi Andrew,

On 2026-08-20 15:02 +0200, Andrew Gaylard wrote:
> The sp_clk_gates[] array previously included 9 infrastructure gate
> clocks (CLK_SYSTEM, CLK_IOCTL, etc.) appended after the 64 DT-visible
> gate clocks. The registration loop used the array index directly as the
> hws[] index, so infrastructure clocks at positions 64-72 overwrote
> hws[PLL_A] through hws[PLL_SYS].
> 
> As a result, DT lookups for <&clkc PLL_E_25> (index 67), PLL_E_2P5
> (66) and PLL_E_112P5 (68) silently resolved to CLK_RBUS, CLK_IOP and
> CLK_SDCTRL0 respectively. The L2SW Ethernet driver believed it was
> holding the PLLE outputs, but was actually double-referencing already-
> critical infrastructure clocks. The real PLLE outputs remained at
> enable_count=0 and were powered down by clk_disable_unused(), causing
> an Ethernet hang on boards with fixed-link MAC-to-MAC connections.
> 
> Fix by splitting infrastructure clocks into a separate sp_clk_infra[]
> array and registering them with a dedicated loop that uses a local hw
> variable rather than an hws[] slot. Since these clocks have no DT
> consumer they do not need to appear in the of_clk provider table.
> 
> With the provider table correct, the L2SW driver's devm_clk_get_enabled()
> calls now hold the actual PLLE outputs, making CLK_IS_CRITICAL on plle
> and its sub-outputs unnecessary. Remove it.
> 
> Signed-off-by: Andrew Gaylard <ag at ffroot.co.za>

This patch does not apply against the tree.

Brian

> ---

>  drivers/clk/clk-sp7021.c | 42 +++++++++++++++++++++++++++++-----------
>  1 file changed, 31 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/clk/clk-sp7021.c b/drivers/clk/clk-sp7021.c
> index 1d067b0af8a7..50c667cbb3dc 100644
> --- a/drivers/clk/clk-sp7021.c
> +++ b/drivers/clk/clk-sp7021.c
> @@ -124,9 +124,14 @@ static const struct sp_clk_gate_info sp_clk_gates[] = {
>  	{ 0x97 },
>  	{ 0x98 },		/* CLK_ICM: Input Capture Module */
>  	{ 0x99, 0, true },	/* CLK_AXI_GLOBAL: AXI interconnect, no driver consumer */
> -	/* Infrastructure clocks: all default to enabled in hardware but
> -	 * have no driver consumer, so marked critical to prevent gating.
> -	 */
> +};
> +
> +/*
> + * Infrastructure clocks have no DT consumer so are not exposed
> + * through the of_clk provider. They are registered separately and
> + * marked CLK_IS_CRITICAL so clk_disable_unused() never gates them.
> + */
> +static const struct sp_clk_gate_info sp_clk_infra[] = {
>  	{ 0x00, 0, true },	/* CLK_SYSTEM:  SYSTEM CLKEN    mo_clken0 bit 0  */
>  	{ 0x03, 0, true },	/* CLK_IOCTL:   IOCTL CLKEN     mo_clken0 bit 3  */
>  	{ 0x04, 0, true },	/* CLK_IOP:     IOP CLKEN       mo_clken0 bit 4  */
> @@ -644,25 +649,23 @@ static int sp7021_clk_probe(struct platform_device *pdev)
>  	/*
>  	 * PLLE and all its sub-outputs are used by the L2SW Ethernet switch
>  	 * (50MHz RMII, 25MHz MII/100M, 2.5MHz MII/10M, 112.5MHz MAC fabric).
> -	 * The L2SW driver explicitly claims these via clock-names in DTS, but
> -	 * CLK_IS_CRITICAL is kept as a belt-and-suspenders guard in case the
> -	 * driver consumer reference isn't sufficient on all board configurations.
> +	 * The L2SW driver explicitly claims these via clock-names in DTS.
>  	 */
>  	hws[PLL_E] = sp_pll_register(dev, "plle", &pd_ext, PLLE_CTL,
> -				     6, 2, 50000000, 0, 0, CLK_IS_CRITICAL);
> +				     6, 2, 50000000, 0, 0, 0);
>  	if (IS_ERR(hws[PLL_E]))
>  		return PTR_ERR(hws[PLL_E]);
>  	pd_e.hw = hws[PLL_E];
>  	hws[PLL_E_2P5] = sp_pll_register(dev, "plle_2p5", &pd_e, PLLE_CTL,
> -					 13, -1, 2500000, 0, 0, CLK_IS_CRITICAL);
> +					 13, -1, 2500000, 0, 0, 0);
>  	if (IS_ERR(hws[PLL_E_2P5]))
>  		return PTR_ERR(hws[PLL_E_2P5]);
>  	hws[PLL_E_25] = sp_pll_register(dev, "plle_25", &pd_e, PLLE_CTL,
> -					12, -1, 25000000, 0, 0, CLK_IS_CRITICAL);
> +					12, -1, 25000000, 0, 0, 0);
>  	if (IS_ERR(hws[PLL_E_25]))
>  		return PTR_ERR(hws[PLL_E_25]);
>  	hws[PLL_E_112P5] = sp_pll_register(dev, "plle_112p5", &pd_e, PLLE_CTL,
> -					   11, -1, 112500000, 0, 0, CLK_IS_CRITICAL);
> +					   11, -1, 112500000, 0, 0, 0);
>  	if (IS_ERR(hws[PLL_E_112P5]))
>  		return PTR_ERR(hws[PLL_E_112P5]);
>  
> @@ -689,7 +692,7 @@ static int sp7021_clk_probe(struct platform_device *pdev)
>  		return PTR_ERR(hws[PLL_SYS]);
>  	pd_sys.hw = hws[PLL_SYS];
>  
> -	/* gates */
> +	/* gates, directly mapped into hws[] for DT lookup */
>  	for (i = 0; i < ARRAY_SIZE(sp_clk_gates); i++) {
>  		char name[10];
>  		u32 j = sp_clk_gates[i].reg;
> @@ -706,6 +709,23 @@ static int sp7021_clk_probe(struct platform_device *pdev)
>  			return PTR_ERR(hws[i]);
>  	}
>  
> +	/* infrastructure gates, not in hws[] */
> +	for (i = 0; i < ARRAY_SIZE(sp_clk_infra); i++) {
> +		char name[14];
> +		u32 j = sp_clk_infra[i].reg;
> +		struct clk_hw *hw;
> +
> +		sprintf(name, "infra_0x%02x", j);
> +		hw = devm_clk_hw_register_gate_parent_data(dev, name, &pd_sys,
> +							   CLK_IS_CRITICAL,
> +							   clk_base + (j >> 4) * 4,
> +							   j & 0x0f,
> +							   CLK_GATE_HIWORD_MASK,
> +							   NULL);
> +		if (IS_ERR(hw))
> +			return PTR_ERR(hw);
> +	}
> +
>  	return devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get, clk_data);
>  }
>  
> -- 
> 2.53.0
> 
> 
>