On Tue, 21 May 2019, Stefan Mavrodiev wrote:
> The function pointer pm_power_off may point to function from other
> module (PSCI for example). If rk808 is removed, pm_power_off is
> overwritten to NULL and the system cannot be powered off.
>
> This patch checks if pm_power_off points to a module function.
>
> Signed-off-by: Stefan Mavrodiev <ste...@olimex.com>
> ---
> Changes in v2:
> - Initial release actually
>
> drivers/mfd/rk808.c | 13 +++++++------
> include/linux/mfd/rk808.h | 1 +
> 2 files changed, 8 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/mfd/rk808.c b/drivers/mfd/rk808.c
> index 94377782d208..c0b179792bbf 100644
> --- a/drivers/mfd/rk808.c
> +++ b/drivers/mfd/rk808.c
> @@ -438,7 +438,6 @@ static int rk808_probe(struct i2c_client *client,
> struct rk808 *rk808;
> const struct rk808_reg_data *pre_init_reg;
> const struct mfd_cell *cells;
> - void (*pm_pwroff_fn)(void);
> int nr_pre_init_regs;
> int nr_cells;
> int pm_off = 0, msb, lsb;
> @@ -475,7 +474,7 @@ static int rk808_probe(struct i2c_client *client,
> nr_pre_init_regs = ARRAY_SIZE(rk805_pre_init_reg);
> cells = rk805s;
> nr_cells = ARRAY_SIZE(rk805s);
> - pm_pwroff_fn = rk805_device_shutdown;
> + rk808->pm_pwroff_fn = rk805_device_shutdown;
> break;
> case RK808_ID:
> rk808->regmap_cfg = &rk808_regmap_config;
> @@ -484,7 +483,7 @@ static int rk808_probe(struct i2c_client *client,
> nr_pre_init_regs = ARRAY_SIZE(rk808_pre_init_reg);
> cells = rk808s;
> nr_cells = ARRAY_SIZE(rk808s);
> - pm_pwroff_fn = rk808_device_shutdown;
> + rk808->pm_pwroff_fn = rk808_device_shutdown;
> break;
> case RK818_ID:
> rk808->regmap_cfg = &rk818_regmap_config;
> @@ -493,7 +492,7 @@ static int rk808_probe(struct i2c_client *client,
> nr_pre_init_regs = ARRAY_SIZE(rk818_pre_init_reg);
> cells = rk818s;
> nr_cells = ARRAY_SIZE(rk818s);
> - pm_pwroff_fn = rk818_device_shutdown;
> + rk808->pm_pwroff_fn = rk818_device_shutdown;
> break;
> default:
> dev_err(&client->dev, "Unsupported RK8XX ID %lu\n",
> @@ -548,7 +547,7 @@ static int rk808_probe(struct i2c_client *client,
> "rockchip,system-power-controller");
> if (pm_off && !pm_power_off) {
> rk808_i2c_client = client;
> - pm_power_off = pm_pwroff_fn;
> + pm_power_off = rk808->pm_pwroff_fn;
> }
>
> return 0;
> @@ -563,7 +562,9 @@ static int rk808_remove(struct i2c_client *client)
> struct rk808 *rk808 = i2c_get_clientdata(client);
>
> regmap_del_irq_chip(client->irq, rk808->irq_data);
> - pm_power_off = NULL;
> +
> + if (rk808->pm_pwroff_fn && pm_power_off == rk808->pm_pwroff_fn)
> + pm_power_off = NULL;
The idea seems sound, but I think you should comment this statement.
--
Lee Jones [李琼斯]
Linaro Services Technical Lead
Linaro.org │ Open source software for ARM SoCs
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