Re: [PATCH 2/3] soc: mtk-pm-domains: do not register smi node as syscon
From: Chun-Jie Chen
Date: Mon May 31 2021 - 07:36:35 EST
On Mon, 2021-05-31 at 12:35 +0800, Hsin-Yi Wang wrote:
> Mediatek requires mmsys clocks to be unprepared during suspend,
> otherwise system has chances to hang.
>
> syscon_regmap_lookup_by_phandle_optional() will attach and prepare
> the
> first clock in smi node, leading to additional prepare to the clock
> which is not balanced with the prepare/unprepare pair in
> resume/suspend
> callbacks.
>
> If a power domain node requests an smi node and the smi node's first
> clock is an mmsys clock, it will results in an unstabke suspend
> resume.
>
> Signed-off-by: Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx>
Reviewed-by: chun-jie.chen <chun-jie.chen@xxxxxxxxxxxx>
> ---
> drivers/soc/mediatek/mtk-pm-domains.c | 12 ++++++++----
> 1 file changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/soc/mediatek/mtk-pm-domains.c
> b/drivers/soc/mediatek/mtk-pm-domains.c
> index 536d8c64b2b4..a9ba71eee4bb 100644
> --- a/drivers/soc/mediatek/mtk-pm-domains.c
> +++ b/drivers/soc/mediatek/mtk-pm-domains.c
> @@ -296,7 +296,7 @@ generic_pm_domain *scpsys_add_one_domain(struct
> scpsys *scpsys, struct device_no
> {
> const struct scpsys_domain_data *domain_data;
> struct scpsys_domain *pd;
> - struct device_node *root_node = scpsys->dev->of_node;
> + struct device_node *root_node = scpsys->dev->of_node,
> *smi_node;
> struct property *prop;
> const char *clk_name;
> int i, ret, num_clks;
> @@ -352,9 +352,13 @@ generic_pm_domain *scpsys_add_one_domain(struct
> scpsys *scpsys, struct device_no
> if (IS_ERR(pd->infracfg))
> return ERR_CAST(pd->infracfg);
>
> - pd->smi = syscon_regmap_lookup_by_phandle_optional(node,
> "mediatek,smi");
> - if (IS_ERR(pd->smi))
> - return ERR_CAST(pd->smi);
> + smi_node = of_parse_phandle(node, "mediatek,smi", 0);
> + if (smi_node) {
> + pd->smi = device_node_to_regmap(smi_node);
> + of_node_put(smi_node);
> + if (IS_ERR(pd->smi))
> + return ERR_CAST(pd->smi);
> + }
>
> num_clks = of_clk_get_parent_count(node);
> if (num_clks > 0) {