Patch "iio: adc: stm32: fix stm32h7_adc_enable error handling" has been added to the 4.15-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    iio: adc: stm32: fix stm32h7_adc_enable error handling

to the 4.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     iio-adc-stm32-fix-stm32h7_adc_enable-error-handling.patch
and it can be found in the queue-4.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From a3b5655ebdb501a98a45c0d3265dca9f2fe0218a Mon Sep 17 00:00:00 2001
From: Fabrice Gasnier <fabrice.gasnier@st.com>
Date: Tue, 23 Jan 2018 17:04:56 +0100
Subject: iio: adc: stm32: fix stm32h7_adc_enable error handling

From: Fabrice Gasnier <fabrice.gasnier@st.com>

commit a3b5655ebdb501a98a45c0d3265dca9f2fe0218a upstream.

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 <fabrice.gasnier@st.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/iio/adc/stm32-adc.c |    7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

--- a/drivers/iio/adc/stm32-adc.c
+++ b/drivers/iio/adc/stm32-adc.c
@@ -765,8 +765,6 @@ static int stm32h7_adc_enable(struct stm
 	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) */
@@ -774,8 +772,11 @@ static int stm32h7_adc_enable(struct stm
 					   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;


Patches currently in stable-queue which might be from fabrice.gasnier@st.com are

queue-4.15/iio-adc-stm32-fix-stm32h7_adc_enable-error-handling.patch