On Tue, 21 Mar 2023 at 23:28, Srinivas Kandagatla
<srinivas.kandagatla@xxxxxxxxxx> wrote:
>
> gfm mux driver does support runtime pm but we never use it while
> accessing registers. Looks like this driver was getting lucky and
> totally depending on other drivers to leave the clk on.
>
> Fix this by doing runtime pm while accessing registers.
Thank you Srini, this fixes the boot regression I see on the RB5
booting v6.1.y and v6.3-rc kernel versions.
Tested-by: Amit Pundir <amit.pundir@xxxxxxxxxx>
>
> Fixes: a2d8f507803e ("clk: qcom: Add support to LPASS AUDIO_CC Glitch Free Mux clocks")
> Cc: stable@xxxxxxxxxxxxxxx
> Reported-by: Amit Pundir <amit.pundir@xxxxxxxxxx>
> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
> ---
> drivers/clk/qcom/lpass-gfm-sm8250.c | 29 ++++++++++++++++++++++++++++-
> 1 file changed, 28 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/clk/qcom/lpass-gfm-sm8250.c b/drivers/clk/qcom/lpass-gfm-sm8250.c
> index 96f476f24eb2..bcf0ea534f7f 100644
> --- a/drivers/clk/qcom/lpass-gfm-sm8250.c
> +++ b/drivers/clk/qcom/lpass-gfm-sm8250.c
> @@ -38,14 +38,37 @@ struct clk_gfm {
> static u8 clk_gfm_get_parent(struct clk_hw *hw)
> {
> struct clk_gfm *clk = to_clk_gfm(hw);
> + int ret;
> + u8 parent;
> +
> + ret = pm_runtime_resume_and_get(clk->priv->dev);
> + if (ret < 0 && ret != -EACCES) {
> + dev_err_ratelimited(clk->priv->dev,
> + "pm_runtime_resume_and_get failed in %s, ret %d\n",
> + __func__, ret);
> + return ret;
> + }
> +
> + parent = readl(clk->gfm_mux) & clk->mux_mask;
> +
> + pm_runtime_mark_last_busy(clk->priv->dev);
>
> - return readl(clk->gfm_mux) & clk->mux_mask;
> + return parent;
> }
>
> static int clk_gfm_set_parent(struct clk_hw *hw, u8 index)
> {
> struct clk_gfm *clk = to_clk_gfm(hw);
> unsigned int val;
> + int ret;
> +
> + ret = pm_runtime_resume_and_get(clk->priv->dev);
> + if (ret < 0 && ret != -EACCES) {
> + dev_err_ratelimited(clk->priv->dev,
> + "pm_runtime_resume_and_get failed in %s, ret %d\n",
> + __func__, ret);
> + return ret;
> + }
>
> val = readl(clk->gfm_mux);
>
> @@ -57,6 +80,8 @@ static int clk_gfm_set_parent(struct clk_hw *hw, u8 index)
>
> writel(val, clk->gfm_mux);
>
> + pm_runtime_mark_last_busy(clk->priv->dev);
> +
> return 0;
> }
>
> @@ -251,6 +276,8 @@ static int lpass_gfm_clk_driver_probe(struct platform_device *pdev)
> if (IS_ERR(cc->base))
> return PTR_ERR(cc->base);
>
> + cc->dev = dev;
> +
> err = devm_pm_runtime_enable(dev);
> if (err)
> return err;
> --
> 2.21.0
>
