| Message ID | 1521650940-11651-7-git-send-email-pierre-yves.mordret@st.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Mar 21, 2018 at 05:49:00PM +0100, Pierre-Yves MORDRET wrote: > Feature prevents I2C lock-ups. Mechanism resets I2C state machine > and releases SCL/SDA signals but preserves I2C registers. > > Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com> > --- > Version history: > v1: > * Initial > v2: > * Don't use i2c engine recovery mechanism since driver > procedure only recover master and not the slave. s/recovery/release/ throughout the patch, please. Recovery is really something else. Also, I think the dev_info's are too noisy in the log files. I'd think the whole driver could be lifted from quite some logging... > --- > --- > drivers/i2c/busses/i2c-stm32f7.c | 27 ++++++++++++++++++++++++--- > 1 file changed, 24 insertions(+), 3 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c > index 91f73e0..9a9c469 100644 > --- a/drivers/i2c/busses/i2c-stm32f7.c > +++ b/drivers/i2c/busses/i2c-stm32f7.c > @@ -718,6 +718,20 @@ static void stm32f7_i2c_smbus_reload(struct stm32f7_i2c_dev *i2c_dev) > writel_relaxed(cr2, i2c_dev->base + STM32F7_I2C_CR2); > } > > +static int stm32f7_i2c_recover_bus(struct i2c_adapter *i2c_adap) > +{ > + struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(i2c_adap); > + > + dev_info(i2c_dev->dev, "Trying to recover bus\n"); > + > + stm32f7_i2c_clr_bits(i2c_dev->base + STM32F7_I2C_CR1, > + STM32F7_I2C_CR1_PE); > + > + stm32f7_i2c_hw_config(i2c_dev); > + > + return 0; > +} > + > static int stm32f7_i2c_wait_free_bus(struct stm32f7_i2c_dev *i2c_dev) > { > u32 status; > @@ -727,12 +741,18 @@ static int stm32f7_i2c_wait_free_bus(struct stm32f7_i2c_dev *i2c_dev) > status, > !(status & STM32F7_I2C_ISR_BUSY), > 10, 1000); > + if (!ret) > + return 0; > + > + dev_info(i2c_dev->dev, "bus busy\n"); > + > + ret = stm32f7_i2c_recover_bus(&i2c_dev->adap); > if (ret) { > - dev_dbg(i2c_dev->dev, "bus busy\n"); > - ret = -EBUSY; > + dev_err(i2c_dev->dev, "Failed to recover the bus (%d)\n", ret); > + return ret; > } > > - return ret; > + return -EBUSY; > } > > static void stm32f7_i2c_xfer_msg(struct stm32f7_i2c_dev *i2c_dev, > @@ -1474,6 +1494,7 @@ static irqreturn_t stm32f7_i2c_isr_error(int irq, void *data) > if (status & STM32F7_I2C_ISR_BERR) { > dev_err(dev, "<%s>: Bus error\n", __func__); > writel_relaxed(STM32F7_I2C_ICR_BERRCF, base + STM32F7_I2C_ICR); > + stm32f7_i2c_recover_bus(&i2c_dev->adap); > f7_msg->result = -EIO; > } > > -- > 2.7.4 >
On 03/24/2018 11:56 PM, Wolfram Sang wrote: > On Wed, Mar 21, 2018 at 05:49:00PM +0100, Pierre-Yves MORDRET wrote: >> Feature prevents I2C lock-ups. Mechanism resets I2C state machine >> and releases SCL/SDA signals but preserves I2C registers. >> >> Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com> >> --- >> Version history: >> v1: >> * Initial >> v2: >> * Don't use i2c engine recovery mechanism since driver >> procedure only recover master and not the slave. > > s/recovery/release/ throughout the patch, please. Recovery is really > something else. Also, I think the dev_info's are too noisy in the log > files. I'd think the whole driver could be lifted from quite some > logging... > ok. will do. Do you have example of info's that we should get rid of ? >> --- >> --- >> drivers/i2c/busses/i2c-stm32f7.c | 27 ++++++++++++++++++++++++--- >> 1 file changed, 24 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c >> index 91f73e0..9a9c469 100644 >> --- a/drivers/i2c/busses/i2c-stm32f7.c >> +++ b/drivers/i2c/busses/i2c-stm32f7.c >> @@ -718,6 +718,20 @@ static void stm32f7_i2c_smbus_reload(struct stm32f7_i2c_dev *i2c_dev) >> writel_relaxed(cr2, i2c_dev->base + STM32F7_I2C_CR2); >> } >> >> +static int stm32f7_i2c_recover_bus(struct i2c_adapter *i2c_adap) >> +{ >> + struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(i2c_adap); >> + >> + dev_info(i2c_dev->dev, "Trying to recover bus\n"); >> + >> + stm32f7_i2c_clr_bits(i2c_dev->base + STM32F7_I2C_CR1, >> + STM32F7_I2C_CR1_PE); >> + >> + stm32f7_i2c_hw_config(i2c_dev); >> + >> + return 0; >> +} >> + >> static int stm32f7_i2c_wait_free_bus(struct stm32f7_i2c_dev *i2c_dev) >> { >> u32 status; >> @@ -727,12 +741,18 @@ static int stm32f7_i2c_wait_free_bus(struct stm32f7_i2c_dev *i2c_dev) >> status, >> !(status & STM32F7_I2C_ISR_BUSY), >> 10, 1000); >> + if (!ret) >> + return 0; >> + >> + dev_info(i2c_dev->dev, "bus busy\n"); >> + >> + ret = stm32f7_i2c_recover_bus(&i2c_dev->adap); >> if (ret) { >> - dev_dbg(i2c_dev->dev, "bus busy\n"); >> - ret = -EBUSY; >> + dev_err(i2c_dev->dev, "Failed to recover the bus (%d)\n", ret); >> + return ret; >> } >> >> - return ret; >> + return -EBUSY; >> } >> >> static void stm32f7_i2c_xfer_msg(struct stm32f7_i2c_dev *i2c_dev, >> @@ -1474,6 +1494,7 @@ static irqreturn_t stm32f7_i2c_isr_error(int irq, void *data) >> if (status & STM32F7_I2C_ISR_BERR) { >> dev_err(dev, "<%s>: Bus error\n", __func__); >> writel_relaxed(STM32F7_I2C_ICR_BERRCF, base + STM32F7_I2C_ICR); >> + stm32f7_i2c_recover_bus(&i2c_dev->adap); >> f7_msg->result = -EIO; >> } >> >> -- >> 2.7.4 >>
diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c index 91f73e0..9a9c469 100644 --- a/drivers/i2c/busses/i2c-stm32f7.c +++ b/drivers/i2c/busses/i2c-stm32f7.c @@ -718,6 +718,20 @@ static void stm32f7_i2c_smbus_reload(struct stm32f7_i2c_dev *i2c_dev) writel_relaxed(cr2, i2c_dev->base + STM32F7_I2C_CR2); } +static int stm32f7_i2c_recover_bus(struct i2c_adapter *i2c_adap) +{ + struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(i2c_adap); + + dev_info(i2c_dev->dev, "Trying to recover bus\n"); + + stm32f7_i2c_clr_bits(i2c_dev->base + STM32F7_I2C_CR1, + STM32F7_I2C_CR1_PE); + + stm32f7_i2c_hw_config(i2c_dev); + + return 0; +} + static int stm32f7_i2c_wait_free_bus(struct stm32f7_i2c_dev *i2c_dev) { u32 status; @@ -727,12 +741,18 @@ static int stm32f7_i2c_wait_free_bus(struct stm32f7_i2c_dev *i2c_dev) status, !(status & STM32F7_I2C_ISR_BUSY), 10, 1000); + if (!ret) + return 0; + + dev_info(i2c_dev->dev, "bus busy\n"); + + ret = stm32f7_i2c_recover_bus(&i2c_dev->adap); if (ret) { - dev_dbg(i2c_dev->dev, "bus busy\n"); - ret = -EBUSY; + dev_err(i2c_dev->dev, "Failed to recover the bus (%d)\n", ret); + return ret; } - return ret; + return -EBUSY; } static void stm32f7_i2c_xfer_msg(struct stm32f7_i2c_dev *i2c_dev, @@ -1474,6 +1494,7 @@ static irqreturn_t stm32f7_i2c_isr_error(int irq, void *data) if (status & STM32F7_I2C_ISR_BERR) { dev_err(dev, "<%s>: Bus error\n", __func__); writel_relaxed(STM32F7_I2C_ICR_BERRCF, base + STM32F7_I2C_ICR); + stm32f7_i2c_recover_bus(&i2c_dev->adap); f7_msg->result = -EIO; }
Feature prevents I2C lock-ups. Mechanism resets I2C state machine and releases SCL/SDA signals but preserves I2C registers. Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com> --- Version history: v1: * Initial v2: * Don't use i2c engine recovery mechanism since driver procedure only recover master and not the slave. --- --- drivers/i2c/busses/i2c-stm32f7.c | 27 ++++++++++++++++++++++++--- 1 file changed, 24 insertions(+), 3 deletions(-)