From mboxrd@z Thu Jan 1 00:00:00 1970 From: jic23@kernel.org (Jonathan Cameron) Date: Sun, 28 Jan 2018 08:19:25 +0000 Subject: [PATCH] iio: adc: stm32: fix stm32h7_adc_enable error handling In-Reply-To: <1516723497-9018-1-git-send-email-fabrice.gasnier@st.com> References: <1516723497-9018-1-git-send-email-fabrice.gasnier@st.com> Message-ID: <20180128081925.524a3e08@archlinux> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue, 23 Jan 2018 17:04:56 +0100 Fabrice Gasnier wrote: > Error handling in stm32h7_adc_enable routine doesn't unwind enable > sequence correctly. ADEN can only be cleared by hardware (e.g. by > writing one to ADDIS). > It's also better to clear ADRDY just after it's been set by hardware. > > Fixes: 95e339b6e85d ("iio: adc: stm32: add support for STM32H7") > > Signed-off-by: Fabrice Gasnier Applied to fixes-togreg-post-rc1 branch of iio.git and marked for stable. Thanks, Jonathan > --- > drivers/iio/adc/stm32-adc.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c > index ca3b865..8177a92 100644 > --- a/drivers/iio/adc/stm32-adc.c > +++ b/drivers/iio/adc/stm32-adc.c > @@ -735,8 +735,6 @@ static int stm32h7_adc_enable(struct stm32_adc *adc) > int ret; > u32 val; > > - /* Clear ADRDY by writing one, then enable ADC */ > - stm32_adc_set_bits(adc, STM32H7_ADC_ISR, STM32H7_ADRDY); > stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADEN); > > /* Poll for ADRDY to be set (after adc startup time) */ > @@ -744,8 +742,11 @@ static int stm32h7_adc_enable(struct stm32_adc *adc) > val & STM32H7_ADRDY, > 100, STM32_ADC_TIMEOUT_US); > if (ret) { > - stm32_adc_clr_bits(adc, STM32H7_ADC_CR, STM32H7_ADEN); > + stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADDIS); > dev_err(&indio_dev->dev, "Failed to enable ADC\n"); > + } else { > + /* Clear ADRDY by writing one */ > + stm32_adc_set_bits(adc, STM32H7_ADC_ISR, STM32H7_ADRDY); > } > > return ret;