On Fri, 12 Feb 2021 21:13:33 +0900 William Breathitt Gray <vilhelm.gray@xxxxxxxxx> wrote: > Only a select set of modes (function, action, etc.) are valid for a > given device configuration. This patch ensures that invalid modes result > in a return -EINVAL. Such a situation should never occur in reality, but > it's good to define a default switch cases for the sake of making the > intent of the code clear. In many of these cases it may make sense to also return early in the good paths rather than share a return 0 at the end of the function? > > Cc: Syed Nayyar Waris <syednwaris@xxxxxxxxx> > Cc: Kamel Bouhara <kamel.bouhara@xxxxxxxxxxx> > Cc: Fabrice Gasnier <fabrice.gasnier@xxxxxx> > Cc: Maxime Coquelin <mcoquelin.stm32@xxxxxxxxx> > Cc: Alexandre Torgue <alexandre.torgue@xxxxxx> > Cc: David Lechner <david@xxxxxxxxxxxxxx> > Signed-off-by: William Breathitt Gray <vilhelm.gray@xxxxxxxxx> > --- > drivers/counter/104-quad-8.c | 10 ++++++++++ > drivers/counter/microchip-tcb-capture.c | 6 ++++++ > drivers/counter/stm32-lptimer-cnt.c | 10 ++++++---- > drivers/counter/stm32-timer-cnt.c | 3 +++ > drivers/counter/ti-eqep.c | 3 +++ > 5 files changed, 28 insertions(+), 4 deletions(-) > > diff --git a/drivers/counter/104-quad-8.c b/drivers/counter/104-quad-8.c > index 9a96296b0625..674263b4d2c4 100644 > --- a/drivers/counter/104-quad-8.c > +++ b/drivers/counter/104-quad-8.c > @@ -273,6 +273,10 @@ static int quad8_function_set(struct counter_device *counter, > *scale = 2; > mode_cfg |= QUAD8_CMR_QUADRATURE_X4; > break; > + default: > + /* should never reach this path */ > + mutex_unlock(&priv->lock); > + return -EINVAL; > } > } > > @@ -367,6 +371,9 @@ static int quad8_action_get(struct counter_device *counter, > case QUAD8_COUNT_FUNCTION_QUADRATURE_X4: > *action = QUAD8_SYNAPSE_ACTION_BOTH_EDGES; > break; > + default: > + /* should never reach this path */ > + return -EINVAL; > } > > return 0; > @@ -529,6 +536,9 @@ static int quad8_count_mode_set(struct counter_device *counter, > case COUNTER_COUNT_MODE_MODULO_N: > cnt_mode = 3; > break; > + default: > + /* should never reach this path */ > + return -EINVAL; > } > > mutex_lock(&priv->lock); > diff --git a/drivers/counter/microchip-tcb-capture.c b/drivers/counter/microchip-tcb-capture.c > index 710acc0a3704..ee979b011012 100644 > --- a/drivers/counter/microchip-tcb-capture.c > +++ b/drivers/counter/microchip-tcb-capture.c > @@ -133,6 +133,9 @@ static int mchp_tc_count_function_set(struct counter_device *counter, > bmr |= ATMEL_TC_QDEN | ATMEL_TC_POSEN; > cmr |= ATMEL_TC_ETRGEDG_RISING | ATMEL_TC_ABETRG | ATMEL_TC_XC0; > break; > + default: > + /* should never reach this path */ > + return -EINVAL; > } > > regmap_write(priv->regmap, ATMEL_TC_BMR, bmr); > @@ -226,6 +229,9 @@ static int mchp_tc_count_action_set(struct counter_device *counter, > case MCHP_TC_SYNAPSE_ACTION_BOTH_EDGE: > edge = ATMEL_TC_ETRGEDG_BOTH; > break; > + default: > + /* should never reach this path */ > + return -EINVAL; > } > > return regmap_write_bits(priv->regmap, > diff --git a/drivers/counter/stm32-lptimer-cnt.c b/drivers/counter/stm32-lptimer-cnt.c > index 937439635d53..daf988e7b208 100644 > --- a/drivers/counter/stm32-lptimer-cnt.c > +++ b/drivers/counter/stm32-lptimer-cnt.c > @@ -206,9 +206,10 @@ static int stm32_lptim_cnt_function_set(struct counter_device *counter, > priv->quadrature_mode = 1; > priv->polarity = STM32_LPTIM_SYNAPSE_ACTION_BOTH_EDGES; > return 0; > + default: > + /* should never reach this path */ > + return -EINVAL; > } > - > - return -EINVAL; > } > > static ssize_t stm32_lptim_cnt_enable_read(struct counter_device *counter, > @@ -326,9 +327,10 @@ static int stm32_lptim_cnt_action_get(struct counter_device *counter, > case STM32_LPTIM_ENCODER_BOTH_EDGE: > *action = priv->polarity; > return 0; > + default: > + /* should never reach this path */ > + return -EINVAL; > } > - > - return -EINVAL; > } > > static int stm32_lptim_cnt_action_set(struct counter_device *counter, > diff --git a/drivers/counter/stm32-timer-cnt.c b/drivers/counter/stm32-timer-cnt.c > index ef2a974a2f10..431a3d08ed6c 100644 > --- a/drivers/counter/stm32-timer-cnt.c > +++ b/drivers/counter/stm32-timer-cnt.c > @@ -296,6 +296,9 @@ static int stm32_action_get(struct counter_device *counter, > /* counts up/down on both TI1FP1 and TI2FP2 edges */ > *action = STM32_SYNAPSE_ACTION_BOTH_EDGES; > break; > + default: > + /* should never reach this path */ > + return -EINVAL; > } > > return 0; > diff --git a/drivers/counter/ti-eqep.c b/drivers/counter/ti-eqep.c > index a60aee1a1a29..7844fdf78a97 100644 > --- a/drivers/counter/ti-eqep.c > +++ b/drivers/counter/ti-eqep.c > @@ -192,6 +192,9 @@ static int ti_eqep_action_get(struct counter_device *counter, > break; > } > break; > + default: > + /* should never reach this path */ > + return -EINVAL; > } > > return 0;
