| Message ID | 20201215092031.152243-2-u.kleine-koenig@pengutronix.de (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | [1/2] hwmon: pwm-fan: Ensure that calculation doesn't discard big period values | expand |
On Tue, 15 Dec 2020 at 09:23, Uwe Kleine-König <u.kleine-koenig@pengutronix.de> wrote: > > pwm_apply_state() does what the legacy functions pwm_config() and > pwm_{en,dis}able() do in a single function call. This simplifies error > handling and is more efficient for new-style PWM hardware drivers. > > Instead of repeatedly querying the PWM framework about the initial PWM > configuration, cache the settings in driver data. > > Also use __set_pwm() in .probe() to have the algorithm calculating the PWM > state in a single place. > > Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> > --- > drivers/hwmon/pwm-fan.c | 47 +++++++++++++++++------------------------ > 1 file changed, 19 insertions(+), 28 deletions(-) > > diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c > index ec171f2b684a..4ccad5a87019 100644 > --- a/drivers/hwmon/pwm-fan.c > +++ b/drivers/hwmon/pwm-fan.c > @@ -25,6 +25,7 @@ > struct pwm_fan_ctx { > struct mutex lock; > struct pwm_device *pwm; > + struct pwm_state pwm_state; > struct regulator *reg_en; > > int irq; > @@ -73,18 +74,17 @@ static int __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm) > { > unsigned long period; > int ret = 0; > - struct pwm_state state = { }; > + struct pwm_state *state = &ctx->pwm_state; > > mutex_lock(&ctx->lock); > if (ctx->pwm_value == pwm) > goto exit_set_pwm_err; > > - pwm_init_state(ctx->pwm, &state); > - period = ctx->pwm->args.period; > - state.duty_cycle = DIV_ROUND_UP(pwm * (period - 1), MAX_PWM); > - state.enabled = pwm ? true : false; > + period = state->period; > + state->duty_cycle = DIV_ROUND_UP(pwm * (period - 1), MAX_PWM); > + state->enabled = pwm ? true : false; > > - ret = pwm_apply_state(ctx->pwm, &state); > + ret = pwm_apply_state(ctx->pwm, state); > if (!ret) > ctx->pwm_value = pwm; > exit_set_pwm_err: > @@ -274,7 +274,9 @@ static void pwm_fan_regulator_disable(void *data) > static void pwm_fan_pwm_disable(void *__ctx) > { > struct pwm_fan_ctx *ctx = __ctx; > - pwm_disable(ctx->pwm); > + > + ctx->pwm_state.enabled = false; > + pwm_apply_state(ctx->pwm, &ctx->pwm_state); > del_timer_sync(&ctx->rpm_timer); > } > > @@ -285,7 +287,6 @@ static int pwm_fan_probe(struct platform_device *pdev) > struct pwm_fan_ctx *ctx; > struct device *hwmon; > int ret; > - struct pwm_state state = { }; > u32 ppr = 2; > > ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL); > @@ -324,22 +325,20 @@ static int pwm_fan_probe(struct platform_device *pdev) > > ctx->pwm_value = MAX_PWM; > > - pwm_init_state(ctx->pwm, &state); > + pwm_init_state(ctx->pwm, &ctx->pwm_state); > + > /* > * __set_pwm assumes that MAX_PWM * (period - 1) fits into an unsigned > * long. Check this here to prevent the fan running at a too low > * frequency. > */ > - if (state.period > ULONG_MAX / MAX_PWM + 1) { > + if (ctx->pwm_state.period > ULONG_MAX / MAX_PWM + 1) { > dev_err(dev, "Configured period too big\n"); > return -EINVAL; > } > > /* Set duty cycle to maximum allowed and enable PWM output */ > - state.duty_cycle = ctx->pwm->args.period - 1; > - state.enabled = true; > - > - ret = pwm_apply_state(ctx->pwm, &state); > + ret = __set_pwm(ctx, MAX_PWM); > if (ret) { > dev_err(dev, "Failed to configure PWM: %d\n", ret); > return ret; > @@ -399,17 +398,16 @@ static int pwm_fan_probe(struct platform_device *pdev) > static int pwm_fan_disable(struct device *dev) > { > struct pwm_fan_ctx *ctx = dev_get_drvdata(dev); > - struct pwm_args args; > int ret; > > - pwm_get_args(ctx->pwm, &args); > - > if (ctx->pwm_value) { > - ret = pwm_config(ctx->pwm, 0, args.period); > + /* keep ctx->pwm_state unmodified for pwm_fan_resume() */ > + struct pwm_state state = ctx->pwm_state; > + state.duty_cycle = 0; > + state.enabled = false; > + ret = pwm_apply_state(ctx->pwm, &state); > if (ret < 0) > return ret; > - > - pwm_disable(ctx->pwm); > } > > if (ctx->reg_en) { > @@ -437,8 +435,6 @@ static int pwm_fan_suspend(struct device *dev) > static int pwm_fan_resume(struct device *dev) > { > struct pwm_fan_ctx *ctx = dev_get_drvdata(dev); > - struct pwm_args pargs; > - unsigned long duty; > int ret; > > if (ctx->reg_en) { > @@ -452,12 +448,7 @@ static int pwm_fan_resume(struct device *dev) > if (ctx->pwm_value == 0) > return 0; > > - pwm_get_args(ctx->pwm, &pargs); > - duty = DIV_ROUND_UP_ULL(ctx->pwm_value * (pargs.period - 1), MAX_PWM); > - ret = pwm_config(ctx->pwm, duty, pargs.period); > - if (ret) > - return ret; > - return pwm_enable(ctx->pwm); > + return pwm_apply_state(ctx->pwm, &ctx->pwm_state); > } > #endif > > -- > 2.29.2 > All looks good to me at first glance. This does conflict with the changes I proposed (https://lore.kernel.org/linux-hwmon/20201212195008.6036-1-pbarker@konsulko.com/T/#t) so we'll need to figure out that out depending which order they get applied in (assuming both changes get accepted). Thanks,
On Tue, Dec 15, 2020 at 10:20:31AM +0100, Uwe Kleine-König wrote: > pwm_apply_state() does what the legacy functions pwm_config() and > pwm_{en,dis}able() do in a single function call. This simplifies error > handling and is more efficient for new-style PWM hardware drivers. > > Instead of repeatedly querying the PWM framework about the initial PWM > configuration, cache the settings in driver data. > > Also use __set_pwm() in .probe() to have the algorithm calculating the PWM > state in a single place. > > Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Can you rebase this patch on top of hwmon-next ? Thanks, Guenter > --- > drivers/hwmon/pwm-fan.c | 47 +++++++++++++++++------------------------ > 1 file changed, 19 insertions(+), 28 deletions(-) > > diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c > index ec171f2b684a..4ccad5a87019 100644 > --- a/drivers/hwmon/pwm-fan.c > +++ b/drivers/hwmon/pwm-fan.c > @@ -25,6 +25,7 @@ > struct pwm_fan_ctx { > struct mutex lock; > struct pwm_device *pwm; > + struct pwm_state pwm_state; > struct regulator *reg_en; > > int irq; > @@ -73,18 +74,17 @@ static int __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm) > { > unsigned long period; > int ret = 0; > - struct pwm_state state = { }; > + struct pwm_state *state = &ctx->pwm_state; > > mutex_lock(&ctx->lock); > if (ctx->pwm_value == pwm) > goto exit_set_pwm_err; > > - pwm_init_state(ctx->pwm, &state); > - period = ctx->pwm->args.period; > - state.duty_cycle = DIV_ROUND_UP(pwm * (period - 1), MAX_PWM); > - state.enabled = pwm ? true : false; > + period = state->period; > + state->duty_cycle = DIV_ROUND_UP(pwm * (period - 1), MAX_PWM); > + state->enabled = pwm ? true : false; > > - ret = pwm_apply_state(ctx->pwm, &state); > + ret = pwm_apply_state(ctx->pwm, state); > if (!ret) > ctx->pwm_value = pwm; > exit_set_pwm_err: > @@ -274,7 +274,9 @@ static void pwm_fan_regulator_disable(void *data) > static void pwm_fan_pwm_disable(void *__ctx) > { > struct pwm_fan_ctx *ctx = __ctx; > - pwm_disable(ctx->pwm); > + > + ctx->pwm_state.enabled = false; > + pwm_apply_state(ctx->pwm, &ctx->pwm_state); > del_timer_sync(&ctx->rpm_timer); > } > > @@ -285,7 +287,6 @@ static int pwm_fan_probe(struct platform_device *pdev) > struct pwm_fan_ctx *ctx; > struct device *hwmon; > int ret; > - struct pwm_state state = { }; > u32 ppr = 2; > > ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL); > @@ -324,22 +325,20 @@ static int pwm_fan_probe(struct platform_device *pdev) > > ctx->pwm_value = MAX_PWM; > > - pwm_init_state(ctx->pwm, &state); > + pwm_init_state(ctx->pwm, &ctx->pwm_state); > + > /* > * __set_pwm assumes that MAX_PWM * (period - 1) fits into an unsigned > * long. Check this here to prevent the fan running at a too low > * frequency. > */ > - if (state.period > ULONG_MAX / MAX_PWM + 1) { > + if (ctx->pwm_state.period > ULONG_MAX / MAX_PWM + 1) { > dev_err(dev, "Configured period too big\n"); > return -EINVAL; > } > > /* Set duty cycle to maximum allowed and enable PWM output */ > - state.duty_cycle = ctx->pwm->args.period - 1; > - state.enabled = true; > - > - ret = pwm_apply_state(ctx->pwm, &state); > + ret = __set_pwm(ctx, MAX_PWM); > if (ret) { > dev_err(dev, "Failed to configure PWM: %d\n", ret); > return ret; > @@ -399,17 +398,16 @@ static int pwm_fan_probe(struct platform_device *pdev) > static int pwm_fan_disable(struct device *dev) > { > struct pwm_fan_ctx *ctx = dev_get_drvdata(dev); > - struct pwm_args args; > int ret; > > - pwm_get_args(ctx->pwm, &args); > - > if (ctx->pwm_value) { > - ret = pwm_config(ctx->pwm, 0, args.period); > + /* keep ctx->pwm_state unmodified for pwm_fan_resume() */ > + struct pwm_state state = ctx->pwm_state; > + state.duty_cycle = 0; > + state.enabled = false; > + ret = pwm_apply_state(ctx->pwm, &state); > if (ret < 0) > return ret; > - > - pwm_disable(ctx->pwm); > } > > if (ctx->reg_en) { > @@ -437,8 +435,6 @@ static int pwm_fan_suspend(struct device *dev) > static int pwm_fan_resume(struct device *dev) > { > struct pwm_fan_ctx *ctx = dev_get_drvdata(dev); > - struct pwm_args pargs; > - unsigned long duty; > int ret; > > if (ctx->reg_en) { > @@ -452,12 +448,7 @@ static int pwm_fan_resume(struct device *dev) > if (ctx->pwm_value == 0) > return 0; > > - pwm_get_args(ctx->pwm, &pargs); > - duty = DIV_ROUND_UP_ULL(ctx->pwm_value * (pargs.period - 1), MAX_PWM); > - ret = pwm_config(ctx->pwm, duty, pargs.period); > - if (ret) > - return ret; > - return pwm_enable(ctx->pwm); > + return pwm_apply_state(ctx->pwm, &ctx->pwm_state); > } > #endif >
diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c index ec171f2b684a..4ccad5a87019 100644 --- a/drivers/hwmon/pwm-fan.c +++ b/drivers/hwmon/pwm-fan.c @@ -25,6 +25,7 @@ struct pwm_fan_ctx { struct mutex lock; struct pwm_device *pwm; + struct pwm_state pwm_state; struct regulator *reg_en; int irq; @@ -73,18 +74,17 @@ static int __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm) { unsigned long period; int ret = 0; - struct pwm_state state = { }; + struct pwm_state *state = &ctx->pwm_state; mutex_lock(&ctx->lock); if (ctx->pwm_value == pwm) goto exit_set_pwm_err; - pwm_init_state(ctx->pwm, &state); - period = ctx->pwm->args.period; - state.duty_cycle = DIV_ROUND_UP(pwm * (period - 1), MAX_PWM); - state.enabled = pwm ? true : false; + period = state->period; + state->duty_cycle = DIV_ROUND_UP(pwm * (period - 1), MAX_PWM); + state->enabled = pwm ? true : false; - ret = pwm_apply_state(ctx->pwm, &state); + ret = pwm_apply_state(ctx->pwm, state); if (!ret) ctx->pwm_value = pwm; exit_set_pwm_err: @@ -274,7 +274,9 @@ static void pwm_fan_regulator_disable(void *data) static void pwm_fan_pwm_disable(void *__ctx) { struct pwm_fan_ctx *ctx = __ctx; - pwm_disable(ctx->pwm); + + ctx->pwm_state.enabled = false; + pwm_apply_state(ctx->pwm, &ctx->pwm_state); del_timer_sync(&ctx->rpm_timer); } @@ -285,7 +287,6 @@ static int pwm_fan_probe(struct platform_device *pdev) struct pwm_fan_ctx *ctx; struct device *hwmon; int ret; - struct pwm_state state = { }; u32 ppr = 2; ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL); @@ -324,22 +325,20 @@ static int pwm_fan_probe(struct platform_device *pdev) ctx->pwm_value = MAX_PWM; - pwm_init_state(ctx->pwm, &state); + pwm_init_state(ctx->pwm, &ctx->pwm_state); + /* * __set_pwm assumes that MAX_PWM * (period - 1) fits into an unsigned * long. Check this here to prevent the fan running at a too low * frequency. */ - if (state.period > ULONG_MAX / MAX_PWM + 1) { + if (ctx->pwm_state.period > ULONG_MAX / MAX_PWM + 1) { dev_err(dev, "Configured period too big\n"); return -EINVAL; } /* Set duty cycle to maximum allowed and enable PWM output */ - state.duty_cycle = ctx->pwm->args.period - 1; - state.enabled = true; - - ret = pwm_apply_state(ctx->pwm, &state); + ret = __set_pwm(ctx, MAX_PWM); if (ret) { dev_err(dev, "Failed to configure PWM: %d\n", ret); return ret; @@ -399,17 +398,16 @@ static int pwm_fan_probe(struct platform_device *pdev) static int pwm_fan_disable(struct device *dev) { struct pwm_fan_ctx *ctx = dev_get_drvdata(dev); - struct pwm_args args; int ret; - pwm_get_args(ctx->pwm, &args); - if (ctx->pwm_value) { - ret = pwm_config(ctx->pwm, 0, args.period); + /* keep ctx->pwm_state unmodified for pwm_fan_resume() */ + struct pwm_state state = ctx->pwm_state; + state.duty_cycle = 0; + state.enabled = false; + ret = pwm_apply_state(ctx->pwm, &state); if (ret < 0) return ret; - - pwm_disable(ctx->pwm); } if (ctx->reg_en) { @@ -437,8 +435,6 @@ static int pwm_fan_suspend(struct device *dev) static int pwm_fan_resume(struct device *dev) { struct pwm_fan_ctx *ctx = dev_get_drvdata(dev); - struct pwm_args pargs; - unsigned long duty; int ret; if (ctx->reg_en) { @@ -452,12 +448,7 @@ static int pwm_fan_resume(struct device *dev) if (ctx->pwm_value == 0) return 0; - pwm_get_args(ctx->pwm, &pargs); - duty = DIV_ROUND_UP_ULL(ctx->pwm_value * (pargs.period - 1), MAX_PWM); - ret = pwm_config(ctx->pwm, duty, pargs.period); - if (ret) - return ret; - return pwm_enable(ctx->pwm); + return pwm_apply_state(ctx->pwm, &ctx->pwm_state); } #endif
pwm_apply_state() does what the legacy functions pwm_config() and pwm_{en,dis}able() do in a single function call. This simplifies error handling and is more efficient for new-style PWM hardware drivers. Instead of repeatedly querying the PWM framework about the initial PWM configuration, cache the settings in driver data. Also use __set_pwm() in .probe() to have the algorithm calculating the PWM state in a single place. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> --- drivers/hwmon/pwm-fan.c | 47 +++++++++++++++++------------------------ 1 file changed, 19 insertions(+), 28 deletions(-)