Re: [PATCH 1/3] clk: exynos-audss: Keep the parent of mout_audss always enabled

From: Javier Martinez Canillas
Date: Wed Jun 11 2014 - 11:58:26 EST


On Wed, Jun 11, 2014 at 7:32 AM, Tushar Behera <tushar.b@xxxxxxxxxxx> wrote:
> When the output clock of AUDSS mux is disabled, we are getting kernel
> oops while doing a clk_get() on other clocks provided by AUDSS. Though
> user manual doesn't specify this dependency, we came across this issue
> while disabling the parent of AUDSS mux clocks.
>
> Keeping the parents of AUDSS mux always enabled fixes this issue.
>
> Signed-off-by: Tushar Behera <tushar.b@xxxxxxxxxxx>
> Signed-off-by: Shaik Ameer Basha <shaik.ameer@xxxxxxxxxxx>
> ---
> drivers/clk/samsung/clk-exynos-audss.c | 17 ++++++++++++++---
> 1 file changed, 14 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/clk/samsung/clk-exynos-audss.c b/drivers/clk/samsung/clk-exynos-audss.c
> index 13eae14c..1542f30 100644
> --- a/drivers/clk/samsung/clk-exynos-audss.c
> +++ b/drivers/clk/samsung/clk-exynos-audss.c
> @@ -30,6 +30,8 @@ static struct clk **clk_table;
> static void __iomem *reg_base;
> static struct clk_onecell_data clk_data;
>
> +static struct clk *pll_ref, *pll_in;
> +
> #define ASS_CLK_SRC 0x0
> #define ASS_CLK_DIV 0x4
> #define ASS_CLK_GATE 0x8
> @@ -83,7 +85,7 @@ static int exynos_audss_clk_probe(struct platform_device *pdev)
> const char *mout_audss_p[] = {"fin_pll", "fout_epll"};
> const char *mout_i2s_p[] = {"mout_audss", "cdclk0", "sclk_audio0"};
> const char *sclk_pcm_p = "sclk_pcm0";
> - struct clk *pll_ref, *pll_in, *cdclk, *sclk_audio, *sclk_pcm_in;
> + struct clk *cdclk, *sclk_audio, *sclk_pcm_in;
> const struct of_device_id *match;
> enum exynos_audss_clk_type variant;
>
> @@ -113,10 +115,14 @@ static int exynos_audss_clk_probe(struct platform_device *pdev)
>
> pll_ref = devm_clk_get(&pdev->dev, "pll_ref");
> pll_in = devm_clk_get(&pdev->dev, "pll_in");
> - if (!IS_ERR(pll_ref))
> + if (!IS_ERR(pll_ref)) {
> mout_audss_p[0] = __clk_get_name(pll_ref);
> - if (!IS_ERR(pll_in))
> + clk_prepare_enable(pll_ref);
> + }
> + if (!IS_ERR(pll_in)) {
> mout_audss_p[1] = __clk_get_name(pll_in);
> + clk_prepare_enable(pll_in);
> + }
> clk_table[EXYNOS_MOUT_AUDSS] = clk_register_mux(NULL, "mout_audss",
> mout_audss_p, ARRAY_SIZE(mout_audss_p),
> CLK_SET_RATE_NO_REPARENT,
> @@ -217,6 +223,11 @@ static int exynos_audss_clk_remove(struct platform_device *pdev)
> clk_unregister(clk_table[i]);
> }
>
> + if (!IS_ERR(pll_in))
> + clk_disable_unprepare(pll_in);
> + if (!IS_ERR(pll_ref))
> + clk_disable_unprepare(pll_ref);
> +
> return 0;
> }
>
> --
> 1.7.9.5
>

Tested-by: Javier Martinez Canillas <javier.martinez@xxxxxxxxxxxxxxx>
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