From mboxrd@z Thu Jan 1 00:00:00 1970 From: gregory.clement@free-electrons.com (Gregory CLEMENT) Date: Mon, 18 Dec 2017 17:12:08 +0100 Subject: [PATCH v4 10/12] thermal: armada: Wait sensors validity before exiting the init callback In-Reply-To: <20171218143643.7714-11-miquel.raynal@free-electrons.com> (Miquel Raynal's message of "Mon, 18 Dec 2017 15:36:41 +0100") References: <20171218143643.7714-1-miquel.raynal@free-electrons.com> <20171218143643.7714-11-miquel.raynal@free-electrons.com> Message-ID: <87h8sohv6v.fsf@free-electrons.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Miquel, On lun., d?c. 18 2017, Miquel Raynal wrote: > The thermal core will check for sensors validity right after the > initialization callback has returned. As the initialization routine make > a reset, the sensors are not ready immediately and the core spawns an > error in the dmesg. Avoid this annoying situation by polling on the > validity bit before exiting from these routines. This also avoid the use > of blind sleeps. > > Suggested-by: David Sniatkiwicz > Signed-off-by: Miquel Raynal Reviewed-by: Gregory CLEMENT > --- > drivers/thermal/armada_thermal.c | 23 ++++++++++++++++++++--- > 1 file changed, 20 insertions(+), 3 deletions(-) > > diff --git a/drivers/thermal/armada_thermal.c b/drivers/thermal/armada_thermal.c > index 2eadd662591d..4a5164ddffe7 100644 > --- a/drivers/thermal/armada_thermal.c > +++ b/drivers/thermal/armada_thermal.c > @@ -23,6 +23,7 @@ > #include > #include > #include > +#include > > /* Thermal Manager Control and Status Register */ > #define PMU_TDC0_SW_RST_MASK (0x1 << 1) > @@ -59,6 +60,9 @@ > #define CONTROL1_EXT_TSEN_SW_RESET BIT(7) > #define CONTROL1_EXT_TSEN_HW_RESETn BIT(8) > > +#define STATUS_POLL_PERIOD_US 1000 > +#define STATUS_POLL_TIMEOUT_US 100000 > + > struct armada_thermal_data; > > /* Marvell EBU Thermal Sensor Dev Structure */ > @@ -155,6 +159,16 @@ static void armada375_init_sensor(struct platform_device *pdev, > msleep(50); > } > > +static void armada_wait_sensor_validity(struct armada_thermal_priv *priv) > +{ > + u32 reg; > + > + readl_relaxed_poll_timeout(priv->status, reg, > + reg & priv->data->is_valid_bit, > + STATUS_POLL_PERIOD_US, > + STATUS_POLL_TIMEOUT_US); > +} > + > static void armada380_init_sensor(struct platform_device *pdev, > struct armada_thermal_priv *priv) > { > @@ -164,7 +178,6 @@ static void armada380_init_sensor(struct platform_device *pdev, > reg |= CONTROL1_EXT_TSEN_HW_RESETn; > reg &= ~CONTROL1_EXT_TSEN_SW_RESET; > writel(reg, priv->control1); > - msleep(10); > > /* Set Tsen Tc Trim to correct default value (errata #132698) */ > if (priv->control0) { > @@ -172,8 +185,10 @@ static void armada380_init_sensor(struct platform_device *pdev, > reg &= ~CONTROL0_TSEN_TC_TRIM_MASK; > reg |= CONTROL0_TSEN_TC_TRIM_VAL; > writel(reg, priv->control0); > - msleep(10); > } > + > + /* Wait the sensors to be valid or the core will warn the user */ > + armada_wait_sensor_validity(priv); > } > > static void armada_ap806_init_sensor(struct platform_device *pdev, > @@ -185,7 +200,9 @@ static void armada_ap806_init_sensor(struct platform_device *pdev, > reg &= ~CONTROL0_TSEN_RESET; > reg |= CONTROL0_TSEN_START | CONTROL0_TSEN_ENABLE; > writel(reg, priv->control0); > - msleep(10); > + > + /* Wait the sensors to be valid or the core will warn the user Just out of curiosity but how the core will warn the user? Gregory > */ > + armada_wait_sensor_validity(priv); > } > > static bool armada_is_valid(struct armada_thermal_priv *priv) > -- > 2.11.0 > -- Gregory Clement, Free Electrons Kernel, drivers, real-time and embedded Linux development, consulting, training and support. http://free-electrons.com