Re: [PATCH 26/31] clk: mediatek: mtk: Implement error handling in register APIs

From: Miles Chen
Date: Wed Jan 26 2022 - 03:17:00 EST


> The remaining clk registration functions do not stop or return errors
> if any clk failed to be registered, nor do they implement error
> handling paths. This may result in a partially working device if any
> step fails.
>
> Make the register functions return proper error codes, and bail out if
> errors occur. Proper cleanup, i.e. unregister any clks that were
> successfully registered, is done in the new error path.
>
> This also makes the |struct clk_data *| argument mandatory, as it is
> used to track the list of clks registered.
>
> Signed-off-by: Chen-Yu Tsai <wenst@xxxxxxxxxxxx>

Reviewed-by: Miles Chen <miles.chen@xxxxxxxxxxxx>

> ---
> drivers/clk/mediatek/clk-mtk.c | 118 ++++++++++++++++++++++++++-------
> drivers/clk/mediatek/clk-mtk.h | 20 +++---
> 2 files changed, 103 insertions(+), 35 deletions(-)
>
> diff --git a/drivers/clk/mediatek/clk-mtk.c b/drivers/clk/mediatek/clk-mtk.c
> index d2c50186cceb..e1977c8e130a 100644
> --- a/drivers/clk/mediatek/clk-mtk.c
> +++ b/drivers/clk/mediatek/clk-mtk.c
> @@ -53,16 +53,19 @@ void mtk_free_clk_data(struct clk_onecell_data *clk_data)
> kfree(clk_data);
> }
>
> -void mtk_clk_register_fixed_clks(const struct mtk_fixed_clk *clks,
> - int num, struct clk_onecell_data *clk_data)
> +int mtk_clk_register_fixed_clks(const struct mtk_fixed_clk *clks, int num,
> + struct clk_onecell_data *clk_data)
> {
> int i;
> struct clk *clk;
>
> + if (!clk_data)
> + return -ENOMEM;
> +
> for (i = 0; i < num; i++) {
> const struct mtk_fixed_clk *rc = &clks[i];
>
> - if (clk_data && !IS_ERR_OR_NULL(clk_data->clks[rc->id]))
> + if (!IS_ERR_OR_NULL(clk_data->clks[rc->id]))
> continue;
>
> clk = clk_register_fixed_rate(NULL, rc->name, rc->parent, 0,
> @@ -70,12 +73,26 @@ void mtk_clk_register_fixed_clks(const struct mtk_fixed_clk *clks,
>
> if (IS_ERR(clk)) {
> pr_err("Failed to register clk %s: %pe\n", rc->name, clk);
> - continue;
> + goto err;
> }
>
> - if (clk_data)
> - clk_data->clks[rc->id] = clk;
> + clk_data->clks[rc->id] = clk;
> }
> +
> + return 0;
> +
> +err:
> + while (--i >= 0) {
> + const struct mtk_fixed_clk *rc = &clks[i];
> +
> + if (IS_ERR_OR_NULL(clk_data->clks[rc->id]))
> + continue;
> +
> + clk_unregister_fixed_rate(clk_data->clks[rc->id]);
> + clk_data->clks[rc->id] = ERR_PTR(-ENOENT);
> + }
> +
> + return PTR_ERR(clk);
> }
> EXPORT_SYMBOL_GPL(mtk_clk_register_fixed_clks);
>
> @@ -99,16 +116,19 @@ void mtk_clk_unregister_fixed_clks(const struct mtk_fixed_clk *clks, int num,
> }
> EXPORT_SYMBOL_GPL(mtk_clk_unregister_fixed_clks);
>
> -void mtk_clk_register_factors(const struct mtk_fixed_factor *clks,
> - int num, struct clk_onecell_data *clk_data)
> +int mtk_clk_register_factors(const struct mtk_fixed_factor *clks, int num,
> + struct clk_onecell_data *clk_data)
> {
> int i;
> struct clk *clk;
>
> + if (!clk_data)
> + return -ENOMEM;
> +
> for (i = 0; i < num; i++) {
> const struct mtk_fixed_factor *ff = &clks[i];
>
> - if (clk_data && !IS_ERR_OR_NULL(clk_data->clks[ff->id]))
> + if (!IS_ERR_OR_NULL(clk_data->clks[ff->id]))
> continue;
>
> clk = clk_register_fixed_factor(NULL, ff->name, ff->parent_name,
> @@ -116,12 +136,26 @@ void mtk_clk_register_factors(const struct mtk_fixed_factor *clks,
>
> if (IS_ERR(clk)) {
> pr_err("Failed to register clk %s: %pe\n", ff->name, clk);
> - continue;
> + goto err;
> }
>
> - if (clk_data)
> - clk_data->clks[ff->id] = clk;
> + clk_data->clks[ff->id] = clk;
> + }
> +
> + return 0;
> +
> +err:
> + while (--i >= 0) {
> + const struct mtk_fixed_factor *ff = &clks[i];
> +
> + if (IS_ERR_OR_NULL(clk_data->clks[ff->id]))
> + continue;
> +
> + clk_unregister_fixed_factor(clk_data->clks[ff->id]);
> + clk_data->clks[ff->id] = ERR_PTR(-ENOENT);
> }
> +
> + return PTR_ERR(clk);
> }
> EXPORT_SYMBOL_GPL(mtk_clk_register_factors);
>
> @@ -253,13 +287,16 @@ static void mtk_clk_unregister_composite(struct clk *clk)
> kfree(mux);
> }
>
> -void mtk_clk_register_composites(const struct mtk_composite *mcs,
> - int num, void __iomem *base, spinlock_t *lock,
> - struct clk_onecell_data *clk_data)
> +int mtk_clk_register_composites(const struct mtk_composite *mcs, int num,
> + void __iomem *base, spinlock_t *lock,
> + struct clk_onecell_data *clk_data)
> {
> struct clk *clk;
> int i;
>
> + if (!clk_data)
> + return -ENOMEM;
> +
> for (i = 0; i < num; i++) {
> const struct mtk_composite *mc = &mcs[i];
>
> @@ -270,12 +307,26 @@ void mtk_clk_register_composites(const struct mtk_composite *mcs,
>
> if (IS_ERR(clk)) {
> pr_err("Failed to register clk %s: %pe\n", mc->name, clk);
> - continue;
> + goto err;
> }
>
> - if (clk_data)
> - clk_data->clks[mc->id] = clk;
> + clk_data->clks[mc->id] = clk;
> + }
> +
> + return 0;
> +
> +err:
> + while (--i >= 0) {
> + const struct mtk_composite *mc = &mcs[i];
> +
> + if (IS_ERR_OR_NULL(clk_data->clks[mcs->id]))
> + continue;
> +
> + mtk_clk_unregister_composite(clk_data->clks[mc->id]);
> + clk_data->clks[mc->id] = ERR_PTR(-ENOENT);
> }
> +
> + return PTR_ERR(clk);
> }
> EXPORT_SYMBOL_GPL(mtk_clk_register_composites);
>
> @@ -299,17 +350,20 @@ void mtk_clk_unregister_composites(const struct mtk_composite *mcs, int num,
> }
> EXPORT_SYMBOL_GPL(mtk_clk_unregister_composites);
>
> -void mtk_clk_register_dividers(const struct mtk_clk_divider *mcds,
> - int num, void __iomem *base, spinlock_t *lock,
> - struct clk_onecell_data *clk_data)
> +int mtk_clk_register_dividers(const struct mtk_clk_divider *mcds, int num,
> + void __iomem *base, spinlock_t *lock,
> + struct clk_onecell_data *clk_data)
> {
> struct clk *clk;
> int i;
>
> + if (!clk_data)
> + return -ENOMEM;
> +
> for (i = 0; i < num; i++) {
> const struct mtk_clk_divider *mcd = &mcds[i];
>
> - if (clk_data && !IS_ERR_OR_NULL(clk_data->clks[mcd->id]))
> + if (!IS_ERR_OR_NULL(clk_data->clks[mcd->id]))
> continue;
>
> clk = clk_register_divider(NULL, mcd->name, mcd->parent_name,
> @@ -318,12 +372,26 @@ void mtk_clk_register_dividers(const struct mtk_clk_divider *mcds,
>
> if (IS_ERR(clk)) {
> pr_err("Failed to register clk %s: %pe\n", mcd->name, clk);
> - continue;
> + goto err;
> }
>
> - if (clk_data)
> - clk_data->clks[mcd->id] = clk;
> + clk_data->clks[mcd->id] = clk;
> + }
> +
> + return 0;
> +
> +err:
> + while (--i >= 0) {
> + const struct mtk_clk_divider *mcd = &mcds[i];
> +
> + if (IS_ERR_OR_NULL(clk_data->clks[mcd->id]))
> + continue;
> +
> + mtk_clk_unregister_composite(clk_data->clks[mcd->id]);
> + clk_data->clks[mcd->id] = ERR_PTR(-ENOENT);
> }
> +
> + return PTR_ERR(clk);
> }
>
> void mtk_clk_unregister_dividers(const struct mtk_clk_divider *mcds, int num,
> diff --git a/drivers/clk/mediatek/clk-mtk.h b/drivers/clk/mediatek/clk-mtk.h
> index 7f902581a115..bf6565aa7319 100644
> --- a/drivers/clk/mediatek/clk-mtk.h
> +++ b/drivers/clk/mediatek/clk-mtk.h
> @@ -34,8 +34,8 @@ struct mtk_fixed_clk {
> .rate = _rate, \
> }
>
> -void mtk_clk_register_fixed_clks(const struct mtk_fixed_clk *clks, int num,
> - struct clk_onecell_data *clk_data);
> +int mtk_clk_register_fixed_clks(const struct mtk_fixed_clk *clks, int num,
> + struct clk_onecell_data *clk_data);
> void mtk_clk_unregister_fixed_clks(const struct mtk_fixed_clk *clks, int num,
> struct clk_onecell_data *clk_data);
>
> @@ -55,8 +55,8 @@ struct mtk_fixed_factor {
> .div = _div, \
> }
>
> -void mtk_clk_register_factors(const struct mtk_fixed_factor *clks, int num,
> - struct clk_onecell_data *clk_data);
> +int mtk_clk_register_factors(const struct mtk_fixed_factor *clks, int num,
> + struct clk_onecell_data *clk_data);
> void mtk_clk_unregister_factors(const struct mtk_fixed_factor *clks, int num,
> struct clk_onecell_data *clk_data);
>
> @@ -150,9 +150,9 @@ struct mtk_composite {
> struct clk *mtk_clk_register_composite(const struct mtk_composite *mc,
> void __iomem *base, spinlock_t *lock);
>
> -void mtk_clk_register_composites(const struct mtk_composite *mcs,
> - int num, void __iomem *base, spinlock_t *lock,
> - struct clk_onecell_data *clk_data);
> +int mtk_clk_register_composites(const struct mtk_composite *mcs, int num,
> + void __iomem *base, spinlock_t *lock,
> + struct clk_onecell_data *clk_data);
> void mtk_clk_unregister_composites(const struct mtk_composite *mcs, int num,
> struct clk_onecell_data *clk_data);
>
> @@ -178,9 +178,9 @@ struct mtk_clk_divider {
> .div_width = _width, \
> }
>
> -void mtk_clk_register_dividers(const struct mtk_clk_divider *mcds, int num,
> - void __iomem *base, spinlock_t *lock,
> - struct clk_onecell_data *clk_data);
> +int mtk_clk_register_dividers(const struct mtk_clk_divider *mcds, int num,
> + void __iomem *base, spinlock_t *lock,
> + struct clk_onecell_data *clk_data);
> void mtk_clk_unregister_dividers(const struct mtk_clk_divider *mcds, int num,
> struct clk_onecell_data *clk_data);
>
> --
> 2.35.0.rc0.227.g00780c9af4-goog
>