From 3cafcfbab9b5f3f1357b415b6ca09911eeb405d6 Mon Sep 17 00:00:00 2001 From: Jonathan Bell Date: Thu, 4 May 2023 15:48:53 +0100 Subject: [PATCH] drivers: hwmon: rp1-adc: check conversion validity before supplying value The SAR ADC architecture may complete a conversion but instability in the comparator can corrupt the result. Such corruption is signalled in the CS ERR bit, asserted alongside each conversion result. Signed-off-by: Jonathan Bell --- drivers/hwmon/rp1-adc.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) --- a/drivers/hwmon/rp1-adc.c +++ b/drivers/hwmon/rp1-adc.c @@ -97,8 +97,14 @@ static int rp1_adc_read(struct rp1_adc_d data->base + RP1_ADC_RWTYPE_SET + RP1_ADC_CS); ret = rp1_adc_ready_wait(data); - if (!ret) - *val = readl(data->base + RP1_ADC_RESULT); + if (ret) + return ret; + + /* Asserted if the completed conversion had a convergence error */ + if (readl(data->base + RP1_ADC_CS) & RP1_ADC_CS_ERR) + return -EIO; + + *val = readl(data->base + RP1_ADC_RESULT); spin_unlock(&data->lock);