RE: [PATCH v2 04/12] i2c: riic: Use pm_runtime_resume_and_get()
From: Biju Das
Date: Tue Jun 25 2024 - 11:53:53 EST
Hi Claudiu,
> -----Original Message-----
> From: Claudiu <claudiu.beznea@xxxxxxxxx>
> Sent: Tuesday, June 25, 2024 1:14 PM
> Subject: [PATCH v2 04/12] i2c: riic: Use pm_runtime_resume_and_get()
>
> From: Claudiu Beznea <claudiu.beznea.uj@xxxxxxxxxxxxxx>
>
> pm_runtime_get_sync() may return with error. In case it returns with error
> dev->power.usage_count needs to be decremented.
> dev->pm_runtime_resume_and_get()
> takes care of this. Thus use it.
>
> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@xxxxxxxxxxxxxx>
> ---
>
> Changes in v2:
> - delete i2c adapter all the time in remove
>
> drivers/i2c/busses/i2c-riic.c | 30 ++++++++++++++++++++++++------
> 1 file changed, 24 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-riic.c b/drivers/i2c/busses/i2c-riic.c index
> 83e4d5e14ab6..002b11b020fa 100644
> --- a/drivers/i2c/busses/i2c-riic.c
> +++ b/drivers/i2c/busses/i2c-riic.c
> @@ -113,6 +113,8 @@ struct riic_irq_desc {
> char *name;
> };
>
> +static const char * const riic_rpm_err_msg = "Failed to runtime
> +resume";
> +
> static inline void riic_writeb(struct riic_dev *riic, u8 val, u8 offset) {
> writeb(val, riic->base + riic->info->regs[offset]); @@ -133,10 +135,14 @@ static int
> riic_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
> struct riic_dev *riic = i2c_get_adapdata(adap);
> struct device *dev = adap->dev.parent;
> unsigned long time_left;
> - int i;
> + int i, ret;
> u8 start_bit;
>
> - pm_runtime_get_sync(dev);
> + ret = pm_runtime_resume_and_get(dev);
> + if (ret) {
> + dev_err(dev, riic_rpm_err_msg);
As at the moment we don't know how to reproduce this error condition
Can we use WARN_ON_ONCE() instead to catch detailed error condition here??
Cheers,
Biju
> + return ret;
> + }
>
> if (riic_readb(riic, RIIC_ICCR2) & ICCR2_BBSY) {
> riic->err = -EBUSY;
> @@ -301,6 +307,7 @@ static const struct i2c_algorithm riic_algo = {
>
> static int riic_init_hw(struct riic_dev *riic, struct i2c_timings *t) {
> + int ret;
> unsigned long rate;
> int total_ticks, cks, brl, brh;
> struct device *dev = riic->adapter.dev.parent; @@ -379,7 +386,11 @@ static int
> riic_init_hw(struct riic_dev *riic, struct i2c_timings *t)
> t->scl_fall_ns / (1000000000 / rate),
> t->scl_rise_ns / (1000000000 / rate), cks, brl, brh);
>
> - pm_runtime_get_sync(dev);
> + ret = pm_runtime_resume_and_get(dev);
> + if (ret) {
> + dev_err(dev, riic_rpm_err_msg);
> + return ret;
> + }
>
> /* Changing the order of accessing IICRST and ICE may break things! */
> riic_writeb(riic, ICCR1_IICRST | ICCR1_SOWP, RIIC_ICCR1); @@ -498,11 +509,18 @@ static void
> riic_i2c_remove(struct platform_device *pdev) {
> struct riic_dev *riic = platform_get_drvdata(pdev);
> struct device *dev = &pdev->dev;
> + int ret;
>
> - pm_runtime_get_sync(dev);
> - riic_writeb(riic, 0, RIIC_ICIER);
> - pm_runtime_put(dev);
> i2c_del_adapter(&riic->adapter);
> +
> + ret = pm_runtime_resume_and_get(dev);
> + if (ret) {
> + dev_err(dev, riic_rpm_err_msg);
> + } else {
> + riic_writeb(riic, 0, RIIC_ICIER);
> + pm_runtime_put(dev);
> + }
> +
> pm_runtime_disable(dev);
> }
>
> --
> 2.39.2
>