Hi,
On 02/28/2014 05:37 PM, Maxime Ripard wrote:
> In order for the DMA controller to work for SDRAM to devices transfers, the AHB
> clock should be reparented on the PLL6.
>
> Force that parenting in the clock driver.
>
> Signed-off-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>
> ---
> drivers/clk/sunxi/clk-sunxi.c | 18 +++++++++++++++++-
> 1 file changed, 17 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/clk/sunxi/clk-sunxi.c b/drivers/clk/sunxi/clk-sunxi.c
> index f6f61cc..a5c5882 100644
> --- a/drivers/clk/sunxi/clk-sunxi.c
> +++ b/drivers/clk/sunxi/clk-sunxi.c
> @@ -1286,7 +1286,7 @@ static void __init of_sunxi_table_clock_setup(const struct of_device_id *clk_mat
> */
> static void __init sunxi_clock_protect(void)
> {
> - struct clk *clk;
> + struct clk *clk, *parent;
>
> /* memory bus clock - sun5i+ */
> clk = clk_get(NULL, "mbus");
> @@ -1307,6 +1307,22 @@ static void __init sunxi_clock_protect(void)
> if (!IS_ERR(clk))
> clk_prepare_enable(clk);
>
> + clk = clk_get(NULL, "ahb1_mux");
> + if (IS_ERR(clk)) {
> + pr_err("Couldn't get AHB1 Mux\n");
> + return;
> + }
I think Emilio already made a similar remark for v1, but since this
is still here in v2, ahb1_mux is only available on sun6i, so
at a minimum the pr_err should be dropped. Preferably I would like
to see this changed to something like:
clk = clk_get(NULL, "ahb1_mux");
parent = clk_get(NULL, "pll6");
if (!IS_ERR(clk) && !IS_ERR(parent))
clk_set_parent(clk, parent);
if (!IS_ERR(parent))
clk_put(parent);
if (!IS_ERR(clk))
clk_put(clk);
> +
> + parent = clk_get(NULL, "pll6");
> + if (IS_ERR(clk)) {
Copy paste error should be IS_ERR(parent).
> + pr_err("Couldn't get PLL6\n");
If we keep things this way this error path should do a clk_put(clk);
> + return;
> + }
> +
> + clk_set_parent(clk, parent);
> +
> + clk_put(clk);
> + clk_put(parent);
> }
>
> static void __init sunxi_init_clocks(void)
>
Regards,
Hans
p.s.
Given Russell's remarks it would also be good to have a
patch in this set dropping the clk_put calls of the existing
enables / protections.
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