| Message ID | 20240122111115.2861835-4-claudiu.beznea.uj@bp.renesas.com |
|---|---|
| State | New |
| Headers | show |
| Series | [01/10] clk: renesas: r9a08g045: Add clock and reset support for watchdog | expand |
On 22.01.2024 19:31, Guenter Roeck wrote: > On 1/22/24 03:11, Claudiu wrote: >> From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> >> >> pm_runtime_put() may return an error code. Check its return status. >> >> Fixes: 2cbc5cd0b55f ("watchdog: Add Watchdog Timer driver for RZ/G2L") >> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> >> --- >> drivers/watchdog/rzg2l_wdt.c | 6 +++++- >> 1 file changed, 5 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/watchdog/rzg2l_wdt.c b/drivers/watchdog/rzg2l_wdt.c >> index 4ab9e7c5e771..0554965027cd 100644 >> --- a/drivers/watchdog/rzg2l_wdt.c >> +++ b/drivers/watchdog/rzg2l_wdt.c >> @@ -144,9 +144,13 @@ static int rzg2l_wdt_start(struct watchdog_device >> *wdev) >> static int rzg2l_wdt_stop(struct watchdog_device *wdev) >> { >> struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev); >> + int ret; >> rzg2l_wdt_reset(priv); >> - pm_runtime_put(wdev->parent); >> + >> + ret = pm_runtime_put(wdev->parent); >> + if (ret < 0) >> + return ret; >> return 0; >> } > > A simple > return pm_runtime_put(); > might do. pm_runtime_put() may return 1 if the device is already suspended though this call trace: pm_runtime_put() -> __pm_runtime_idle() -> rpm_idle() -> rpm_suspend() -> rpm_check_suspend_allowed() [1] That return value is not considered error thus I wanted to consider it here, too. [1] https://elixir.bootlin.com/linux/latest/source/drivers/base/power/runtime.c#L278 > > However, one question: Given that pm_runtime_put() returns -ENOSYS if > CONFIG_PM is disabled, that means the driver will depend on CONFIG_PM=y. Indeed, the driver depends on CONFIG_PM=y for proper working. It is for devices selecting ARCH_RZG2L and RZ/V2M (ARM64 based uarch) which select CONFIG_PM=y: https://elixir.bootlin.com/linux/latest/source/drivers/soc/renesas/Kconfig#L45 The driver is written with CONFIG_PM=y dependency in mind (e.g. the clocks are enabled though runtime PM APIs). > Assuming this is intentional, would it make sense to explicitly declare > that dependency in Kconfig ? It doesn't seem to make any sense to build > the driver if it won't work anyway. The dependency exists there for ARCH_RZG2L and RZ/V2M devices but not directly and it is not strict (in the sense that we allow to build the driver w/o CONFIG_PM (I think this is good to check build on different configurations, the COMPILE_TEST is there anyway in [1]) ). E.g.: RENESAS_RZG2LWDT depends on ARCH_RENESAS [1] ARCH_RENESAS is the ARMv8 uarch flag [2] SOC_RENESAS is set if ARCH_RENESAS [3] ARCH_RZG2L is visible only if SOC_RENESAS [4] ARCH_RZG2L selects PM [5] RZ/V2M selects PM [6] Please let me know what do you think about it? Thank you, Claudiu Beznea [1] https://elixir.bootlin.com/linux/latest/source/drivers/watchdog/Kconfig#L913 [2] https://elixir.bootlin.com/linux/latest/source/arch/arm64/Kconfig.platforms#L273 [3] https://elixir.bootlin.com/linux/latest/source/drivers/soc/renesas/Kconfig#L2 [4] https://elixir.bootlin.com/linux/latest/source/drivers/soc/renesas/Kconfig#L9 [5] https://elixir.bootlin.com/linux/latest/source/drivers/soc/renesas/Kconfig#L45 [6] https://elixir.bootlin.com/linux/latest/source/drivers/soc/renesas/Kconfig#L328 > > Thanks, > Guenter >
On 1/22/24 23:02, claudiu beznea wrote: > > > On 22.01.2024 19:31, Guenter Roeck wrote: >> On 1/22/24 03:11, Claudiu wrote: >>> From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> >>> >>> pm_runtime_put() may return an error code. Check its return status. >>> >>> Fixes: 2cbc5cd0b55f ("watchdog: Add Watchdog Timer driver for RZ/G2L") >>> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> >>> --- >>> drivers/watchdog/rzg2l_wdt.c | 6 +++++- >>> 1 file changed, 5 insertions(+), 1 deletion(-) >>> >>> diff --git a/drivers/watchdog/rzg2l_wdt.c b/drivers/watchdog/rzg2l_wdt.c >>> index 4ab9e7c5e771..0554965027cd 100644 >>> --- a/drivers/watchdog/rzg2l_wdt.c >>> +++ b/drivers/watchdog/rzg2l_wdt.c >>> @@ -144,9 +144,13 @@ static int rzg2l_wdt_start(struct watchdog_device >>> *wdev) >>> static int rzg2l_wdt_stop(struct watchdog_device *wdev) >>> { >>> struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev); >>> + int ret; >>> rzg2l_wdt_reset(priv); >>> - pm_runtime_put(wdev->parent); >>> + >>> + ret = pm_runtime_put(wdev->parent); >>> + if (ret < 0) >>> + return ret; >>> return 0; >>> } >> >> A simple >> return pm_runtime_put(); >> might do. > > pm_runtime_put() may return 1 if the device is already suspended though > this call trace: > > pm_runtime_put() -> > __pm_runtime_idle() -> > rpm_idle() -> > rpm_suspend() -> > rpm_check_suspend_allowed() [1] > > That return value is not considered error thus I wanted to consider it > here, too. > Good point. > [1] > https://elixir.bootlin.com/linux/latest/source/drivers/base/power/runtime.c#L278 > >> >> However, one question: Given that pm_runtime_put() returns -ENOSYS if >> CONFIG_PM is disabled, that means the driver will depend on CONFIG_PM=y. > > Indeed, the driver depends on CONFIG_PM=y for proper working. It is for > devices selecting ARCH_RZG2L and RZ/V2M (ARM64 based uarch) which select > CONFIG_PM=y: > https://elixir.bootlin.com/linux/latest/source/drivers/soc/renesas/Kconfig#L45 > > The driver is written with CONFIG_PM=y dependency in mind (e.g. the clocks > are enabled though runtime PM APIs). > >> Assuming this is intentional, would it make sense to explicitly declare >> that dependency in Kconfig ? It doesn't seem to make any sense to build >> the driver if it won't work anyway. > > The dependency exists there for ARCH_RZG2L and RZ/V2M devices but not > directly and it is not strict (in the sense that we allow to build the > driver w/o CONFIG_PM (I think this is good to check build on different > configurations, the COMPILE_TEST is there anyway in [1]) ). E.g.: > > RENESAS_RZG2LWDT depends on ARCH_RENESAS [1] > ARCH_RENESAS is the ARMv8 uarch flag [2] > SOC_RENESAS is set if ARCH_RENESAS [3] > ARCH_RZG2L is visible only if SOC_RENESAS [4] > ARCH_RZG2L selects PM [5] > RZ/V2M selects PM [6] > > Please let me know what do you think about it? > If the driver indeed depends on CONFIG_PM, that should be made explicit. Guenter > Thank you, > Claudiu Beznea > > > [1] > https://elixir.bootlin.com/linux/latest/source/drivers/watchdog/Kconfig#L913 > [2] > https://elixir.bootlin.com/linux/latest/source/arch/arm64/Kconfig.platforms#L273 > [3] > https://elixir.bootlin.com/linux/latest/source/drivers/soc/renesas/Kconfig#L2 > [4] > https://elixir.bootlin.com/linux/latest/source/drivers/soc/renesas/Kconfig#L9 > [5] > https://elixir.bootlin.com/linux/latest/source/drivers/soc/renesas/Kconfig#L45 > [6] > https://elixir.bootlin.com/linux/latest/source/drivers/soc/renesas/Kconfig#L328 > > >> >> Thanks, >> Guenter >> >
diff --git a/drivers/watchdog/rzg2l_wdt.c b/drivers/watchdog/rzg2l_wdt.c index 4ab9e7c5e771..0554965027cd 100644 --- a/drivers/watchdog/rzg2l_wdt.c +++ b/drivers/watchdog/rzg2l_wdt.c @@ -144,9 +144,13 @@ static int rzg2l_wdt_start(struct watchdog_device *wdev) static int rzg2l_wdt_stop(struct watchdog_device *wdev) { struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev); + int ret; rzg2l_wdt_reset(priv); - pm_runtime_put(wdev->parent); + + ret = pm_runtime_put(wdev->parent); + if (ret < 0) + return ret; return 0; }