Subject: [PATCH 1/2] clk: Do not complain about correctly set read-only muxes when assigning clock parents from device tree

From: [email-masked] (Shawn Guo)
Date: Tue, 2 Dec 2014 16:20:14 +0800

On Mon, Dec 01, 2014 at 05:42:42PM +0100, Philipp Zabel wrote:
> Assigning a clock parent to a mux with the CLK_MUX_READ_ONLY flag causes an
> error "clk: failed to reparent read_only_mux to already_set_parent: -38"
> even if the hardware is already set to the correct parent clock.
> 
> This patch avoids the error message by checking whether the correct parent
> is already set before calling clk_set_parent. This allows to use the
> assigned-clock-parents device tree binding for clock muxes that are not
> allowed to be changed anymore at the time of_clk_set_defaults is called.
> 
> Signed-off-by: Philipp Zabel <[email-masked]>

Philipp,

The patch should be sent to Mike Turquette <[email-masked]>.  The
patch itself makes sense to me, so

Acked-by: Shawn Guo <[email-masked]>

Shawn

> ---
>  drivers/clk/clk-conf.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/clk/clk-conf.c b/drivers/clk/clk-conf.c
> index aad4796..ca8dc86 100644
> --- a/drivers/clk/clk-conf.c
> +++ b/drivers/clk/clk-conf.c
> @@ -62,7 +62,8 @@ static int __set_clk_parents(struct device_node *node, bool clk_supplier)
>  			goto err;
>  		}
>  
> -		rc = clk_set_parent(clk, pclk);
> +		if (pclk != __clk_get_parent(clk))
> +			rc = clk_set_parent(clk, pclk);
>  		if (rc < 0)
>  			pr_err("clk: failed to reparent %s to %s: %d\n",
>  			       __clk_get_name(clk), __clk_get_name(pclk), rc);
> -- 
> 2.1.3
>