lkml.org 
[lkml]   [2014]   [Mar]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [linux-sunxi] [PATCH v2 2/5] clk: sun6i: Reparent AHB clock on PLL6
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@free-electrons.com>
> ---
> 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.


\
 
 \ /
  Last update: 2014-03-01 18:01    [W:0.105 / U:0.108 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site