iio: adis16480: fix FNCTIO_CTRL corruption when enabling IRQ

PATCH In review Vlad Banea 4 participants 6 messages Mar 9, 2016 – Mar 12, 2016 2 messages not in the archive

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IIO Analog Devices IIO drivers

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Vlad Banea

author

2016-03-09 05:28 UTC #0 lore raw

PATCH 1/1 iio: adis16480: fix FNCTIO_CTRL corruption when enabling IRQ

Enabling the IRQ should leave all other settings in the FNCTIO_CTRL register untouched: read the whole register, toggle just the enable bit, before writing it back.

---
 drivers/iio/imu/adis16480.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

drivers/iio/imu/adis16480.c +13 -2

index b94bfd3..8473859 100644
@@ -738,8 +738,19 @@ static int adis16480_stop_device(struct iio_dev *indio_dev)
 
 static int adis16480_enable_irq(struct adis *adis, bool enable)
 {
-	return adis_write_reg_16(adis, ADIS16480_REG_FNCTIO_CTRL,
-		enable ? BIT(3) : 0);
+	u16 fnctio_ctrl;
+	int ret;
+
+	ret = adis_read_reg_16(adis, ADIS16480_REG_FNCTIO_CTRL, &fnctio_ctrl);
+	if (ret < 0)
+		return ret;
+
+	if (enable)
+		fnctio_ctrl |= BIT(3);
+	else
+		fnctio_ctrl &= ~BIT(3);
+
+	return adis_write_reg_16(adis, ADIS16480_REG_FNCTIO_CTRL, fnctio_ctrl);
 }
 
 static int adis16480_initial_setup(struct iio_dev *indio_dev)

Signature · 1 line

2.7.1

Lars-Peter Clausen

2016-03-09 09:52 UTC #1 lore raw

Quoted 3 lines · Vlad Banea

Enabling the IRQ should leave all other settings in the FNCTIO_CTRL register untouched: read the whole register, toggle just the enable bit, before writing it back.

Hi,

Thanks for the patch. Looks good in general, but it's not a fix. The driver does not write this register anywhere else and the reset default value is 0x00. So we don't corrupt any other settings since, 0x00 and BIT(3) are the only two settings the driver does at the moment.

If the patch is in preparation of future changes that are going to set/clear other bits of the register this should be noted in the commit message.

The reason I'm so pedantic here is because fix generally means that the patch needs to be backported to older kernel versions, which is not the case here.

- Lars

Quoted 31 lines

---
 drivers/iio/imu/adis16480.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

drivers/iio/imu/adis16480.c +13 -2

index b94bfd3..8473859 100644
@@ -738,8 +738,19 @@ static int adis16480_stop_device(struct iio_dev *indio_dev)
 
 static int adis16480_enable_irq(struct adis *adis, bool enable)
 {
-	return adis_write_reg_16(adis, ADIS16480_REG_FNCTIO_CTRL,
-		enable ? BIT(3) : 0);
+	u16 fnctio_ctrl;
+	int ret;
+
+	ret = adis_read_reg_16(adis, ADIS16480_REG_FNCTIO_CTRL, &fnctio_ctrl);
+	if (ret < 0)
+		return ret;
+
+	if (enable)
+		fnctio_ctrl |= BIT(3);
+	else
+		fnctio_ctrl &= ~BIT(3);
+
+	return adis_write_reg_16(adis, ADIS16480_REG_FNCTIO_CTRL, fnctio_ctrl);
 }
 
 static int adis16480_initial_setup(struct iio_dev *indio_dev)

A message that is not in the archive (sent off-list or not yet received): CACBkv7uBy_eJv5aZRvaHAn6VY0rrjJkWF4mBXvv9_4wFJA9qiQ@mail.gmail.com

Lars-Peter Clausen

2016-03-09 12:21 UTC #3 lore raw

Hi,

Hm, right. But the intention of the driver is to use DIO1. Changing this to DIO2 by default will break all existing users.

This change should be part of a patch which allows to configure which interrupt output to use and also the interrupt polarity.

- Lars

Quoted 74 lines · Vlad Banea

Hi,

Thanks for your answer. I'm using this driver with the ADIS16485 device and the default value for this register is 0x000D:
http://www.analog.com/media/en/technical-documentation/data-sheets/ADIS16485.pdf
(Table 89)

When the driver enables the interrupt, the Data Ready Line selection and polarity are changed, and I never receive the interrupt.

Vlad

On Wed, Mar 9, 2016 at 4:22 AM, Lars-Peter Clausen <[email protected] <mailto:[email protected]>> wrote:

    On 03/09/2016 06:28 AM, Vlad Banea wrote:
    > Enabling the IRQ should leave all other settings in the FNCTIO_CTRL
    > register untouched: read the whole register, toggle just the enable bit,
    > before writing it back.

    Hi,

    Thanks for the patch. Looks good in general, but it's not a fix. The driver
    does not write this register anywhere else and the reset default value is
    0x00. So we don't corrupt any other settings since, 0x00 and BIT(3) are the
    only two settings the driver does at the moment.

    If the patch is in preparation of future changes that are going to set/clear
    other bits of the register this should be noted in the commit message.

    The reason I'm so pedantic here is because fix generally means that the
    patch needs to be backported to older kernel versions, which is not the case
    here.

    - Lars


    > ---
    >  drivers/iio/imu/adis16480.c | 15 +++++++++++++--
    >  1 file changed, 13 insertions(+), 2 deletions(-)
    >
    > diff --git a/drivers/iio/imu/adis16480.c b/drivers/iio/imu/adis16480.c
    > index b94bfd3..8473859 100644
    > --- a/drivers/iio/imu/adis16480.c
    > +++ b/drivers/iio/imu/adis16480.c
    > @@ -738,8 +738,19 @@ static int adis16480_stop_device(struct iio_dev
    *indio_dev)
    >
    >  static int adis16480_enable_irq(struct adis *adis, bool enable)
    >  {
    > -     return adis_write_reg_16(adis, ADIS16480_REG_FNCTIO_CTRL,
    > -             enable ? BIT(3) : 0);
    > +     u16 fnctio_ctrl;
    > +     int ret;
    > +
    > +     ret = adis_read_reg_16(adis, ADIS16480_REG_FNCTIO_CTRL,
    &fnctio_ctrl);
    > +     if (ret < 0)
    > +             return ret;
    > +
    > +     if (enable)
    > +             fnctio_ctrl |= BIT(3);
    > +     else
    > +             fnctio_ctrl &= ~BIT(3);
    > +
    > +     return adis_write_reg_16(adis, ADIS16480_REG_FNCTIO_CTRL,
    fnctio_ctrl);
    >  }
    >
    >  static int adis16480_initial_setup(struct iio_dev *indio_dev)
    >

A message that is not in the archive (sent off-list or not yet received): CACBkv7v=D7frj6Uo7c9pd5aohVv_OUJU4jpoHdhP+S5KgmqHAw@mail.gmail.com

Lars-Peter Clausen

2016-03-09 16:46 UTC #5 lore raw

Hi,

The intention was to use DIO1 by default, which the driver does and which has been tested. With your patch it uses DIO2 by default, which is the correct setting for your board.

- Lars

Quoted 119 lines · Vlad Banea

Hi,

Since the driver is never setting the FNCTIO_CTRL register, I'd say the intention is to use the default settings.
The clearing of all the other bits as we toggle the interrupt seems unintentional, and that's what the proposed patch addresses. The ADIS16485 device is not usable without this patch with the most up to date driver, and becomes fully functional when the patch is applied..

I wouldn't mind contributing to allow the driver to fully configure this register, but I'm not sure what user interface this should go through.

Thanks
Vlad

On Wed, Mar 9, 2016 at 7:21 AM, Lars-Peter Clausen <[email protected] <mailto:[email protected]>> wrote:

    Hi,

    Hm, right. But the intention of the driver is to use DIO1. Changing this to
    DIO2 by default will break all existing users.

    This change should be part of a patch which allows to configure which
    interrupt output to use and also the interrupt polarity.

    - Lars

    On 03/09/2016 12:39 PM, Vlad Banea wrote:
    > Hi,
    >
    > Thanks for your answer. I'm using this driver with the ADIS16485
    device and
    > the default value for this register is 0x000D:
    >
    http://www.analog.com/media/en/technical-documentation/data-sheets/ADIS16485.pdf
    > (Table 89)
    >
    > When the driver enables the interrupt, the Data Ready Line selection and
    > polarity are changed, and I never receive the interrupt.
    >
    > Vlad
    >
    >
    > On Wed, Mar 9, 2016 at 4:22 AM, Lars-Peter Clausen <[email protected]
    <mailto:[email protected]>
    > <mailto:[email protected] <mailto:[email protected]>>> wrote:
    >
    >     On 03/09/2016 06:28 AM, Vlad Banea wrote:
    >     > Enabling the IRQ should leave all other settings in the FNCTIO_CTRL
    >     > register untouched: read the whole register, toggle just the
    enable bit,
    >     > before writing it back.
    >
    >     Hi,
    >
    >     Thanks for the patch. Looks good in general, but it's not a fix.
    The driver
    >     does not write this register anywhere else and the reset default
    value is
    >     0x00. So we don't corrupt any other settings since, 0x00 and
    BIT(3) are the
    >     only two settings the driver does at the moment.
    >
    >     If the patch is in preparation of future changes that are going to
    set/clear
    >     other bits of the register this should be noted in the commit message.
    >
    >     The reason I'm so pedantic here is because fix generally means
    that the
    >     patch needs to be backported to older kernel versions, which is
    not the case
    >     here.
    >
    >     - Lars
    >
    >
    >     > ---
    >     >  drivers/iio/imu/adis16480.c | 15 +++++++++++++--
    >     >  1 file changed, 13 insertions(+), 2 deletions(-)
    >     >
    >     > diff --git a/drivers/iio/imu/adis16480.c
    b/drivers/iio/imu/adis16480.c
    >     > index b94bfd3..8473859 100644
    >     > --- a/drivers/iio/imu/adis16480.c
    >     > +++ b/drivers/iio/imu/adis16480.c
    >     > @@ -738,8 +738,19 @@ static int adis16480_stop_device(struct iio_dev
    >     *indio_dev)
    >     >
    >     >  static int adis16480_enable_irq(struct adis *adis, bool enable)
    >     >  {
    >     > -     return adis_write_reg_16(adis, ADIS16480_REG_FNCTIO_CTRL,
    >     > -             enable ? BIT(3) : 0);
    >     > +     u16 fnctio_ctrl;
    >     > +     int ret;
    >     > +
    >     > +     ret = adis_read_reg_16(adis, ADIS16480_REG_FNCTIO_CTRL,
    >     &fnctio_ctrl);
    >     > +     if (ret < 0)
    >     > +             return ret;
    >     > +
    >     > +     if (enable)
    >     > +             fnctio_ctrl |= BIT(3);
    >     > +     else
    >     > +             fnctio_ctrl &= ~BIT(3);
    >     > +
    >     > +     return adis_write_reg_16(adis, ADIS16480_REG_FNCTIO_CTRL,
    >     fnctio_ctrl);
    >     >  }
    >     >
    >     >  static int adis16480_initial_setup(struct iio_dev *indio_dev)
    >     >
    >
    >

Vlad Banea

2016-03-09 17:06 UTC #6 lore raw

Hi,

Ok, I'll change the patch to keep the old behaviour as the default one but add a device tree settings for selecting the DIO and polarity as you said.

Vlad

Quoted 129 lines · Lars-Peter Clausen

Hi,

The intention was to use DIO1 by default, which the driver does and which has been tested. With your patch it uses DIO2 by default, which is the correct setting for your board.

- Lars

Quoted 119 lines · Vlad Banea

Hi,

I wouldn't mind contributing to allow the driver to fully configure this register, but I'm not sure what user interface this should go through.

Thanks
Vlad

On Wed, Mar 9, 2016 at 7:21 AM, Lars-Peter Clausen <[email protected] <mailto:[email protected]>> wrote:

    Hi,

    Hm, right. But the intention of the driver is to use DIO1. Changing this to
    DIO2 by default will break all existing users.

    This change should be part of a patch which allows to configure which
    interrupt output to use and also the interrupt polarity.

    - Lars

    On 03/09/2016 12:39 PM, Vlad Banea wrote:
    > Hi,
    >
    > Thanks for your answer. I'm using this driver with the ADIS16485
    device and
    > the default value for this register is 0x000D:
    >
    http://www.analog.com/media/en/technical-documentation/data-sheets/ADIS16485.pdf
    > (Table 89)
    >
    > When the driver enables the interrupt, the Data Ready Line selection and
    > polarity are changed, and I never receive the interrupt.
    >
    > Vlad
    >
    >
    > On Wed, Mar 9, 2016 at 4:22 AM, Lars-Peter Clausen <[email protected]
    <mailto:[email protected]>
    > <mailto:[email protected] <mailto:[email protected]>>> wrote:
    >
    >     On 03/09/2016 06:28 AM, Vlad Banea wrote:
    >     > Enabling the IRQ should leave all other settings in the FNCTIO_CTRL
    >     > register untouched: read the whole register, toggle just the
    enable bit,
    >     > before writing it back.
    >
    >     Hi,
    >
    >     Thanks for the patch. Looks good in general, but it's not a fix.
    The driver
    >     does not write this register anywhere else and the reset default
    value is
    >     0x00. So we don't corrupt any other settings since, 0x00 and
    BIT(3) are the
    >     only two settings the driver does at the moment.
    >
    >     If the patch is in preparation of future changes that are going to
    set/clear
    >     other bits of the register this should be noted in the commit message.
    >
    >     The reason I'm so pedantic here is because fix generally means
    that the
    >     patch needs to be backported to older kernel versions, which is
    not the case
    >     here.
    >
    >     - Lars
    >
    >
    >     > ---
    >     >  drivers/iio/imu/adis16480.c | 15 +++++++++++++--
    >     >  1 file changed, 13 insertions(+), 2 deletions(-)
    >     >
    >     > diff --git a/drivers/iio/imu/adis16480.c
    b/drivers/iio/imu/adis16480.c
    >     > index b94bfd3..8473859 100644
    >     > --- a/drivers/iio/imu/adis16480.c
    >     > +++ b/drivers/iio/imu/adis16480.c
    >     > @@ -738,8 +738,19 @@ static int adis16480_stop_device(struct iio_dev
    >     *indio_dev)
    >     >
    >     >  static int adis16480_enable_irq(struct adis *adis, bool enable)
    >     >  {
    >     > -     return adis_write_reg_16(adis, ADIS16480_REG_FNCTIO_CTRL,
    >     > -             enable ? BIT(3) : 0);
    >     > +     u16 fnctio_ctrl;
    >     > +     int ret;
    >     > +
    >     > +     ret = adis_read_reg_16(adis, ADIS16480_REG_FNCTIO_CTRL,
    >     &fnctio_ctrl);
    >     > +     if (ret < 0)
    >     > +             return ret;
    >     > +
    >     > +     if (enable)
    >     > +             fnctio_ctrl |= BIT(3);
    >     > +     else
    >     > +             fnctio_ctrl &= ~BIT(3);
    >     > +
    >     > +     return adis_write_reg_16(adis, ADIS16480_REG_FNCTIO_CTRL,
    >     fnctio_ctrl);
    >     >  }
    >     >
    >     >  static int adis16480_initial_setup(struct iio_dev *indio_dev)
    >     >
    >
    >

Jonathan Cameron

maintainer

2016-03-12 11:14 UTC #7 lore raw

Quoted 5 lines · Vlad Banea

Hi,
Ok, I'll change the patch to keep the old behaviour as the default one but add a device tree settings for selecting the DIO and polarity as you said.

Cool. As a process related aside, please make sure to cc the list [email protected]

Jonathan

Quoted 133 lines

Vlad

Quoted 129 lines · Lars-Peter Clausen

Hi,

The intention was to use DIO1 by default, which the driver does and which has been tested. With your patch it uses DIO2 by default, which is the correct setting for your board.

- Lars

Quoted 119 lines · Vlad Banea

Hi,

I wouldn't mind contributing to allow the driver to fully configure this register, but I'm not sure what user interface this should go through.

Thanks
Vlad

On Wed, Mar 9, 2016 at 7:21 AM, Lars-Peter Clausen <[email protected] <mailto:[email protected]>> wrote:

    Hi,

    Hm, right. But the intention of the driver is to use DIO1. Changing this to
    DIO2 by default will break all existing users.

    This change should be part of a patch which allows to configure which
    interrupt output to use and also the interrupt polarity.

    - Lars

    On 03/09/2016 12:39 PM, Vlad Banea wrote:
    > Hi,
    >
    > Thanks for your answer. I'm using this driver with the ADIS16485
    device and
    > the default value for this register is 0x000D:
    >
    http://www.analog.com/media/en/technical-documentation/data-sheets/ADIS16485.pdf
    > (Table 89)
    >
    > When the driver enables the interrupt, the Data Ready Line selection and
    > polarity are changed, and I never receive the interrupt.
    >
    > Vlad
    >
    >
    > On Wed, Mar 9, 2016 at 4:22 AM, Lars-Peter Clausen <[email protected]
    <mailto:[email protected]>
    > <mailto:[email protected] <mailto:[email protected]>>> wrote:
    >
    >     On 03/09/2016 06:28 AM, Vlad Banea wrote:
    >     > Enabling the IRQ should leave all other settings in the FNCTIO_CTRL
    >     > register untouched: read the whole register, toggle just the
    enable bit,
    >     > before writing it back.
    >
    >     Hi,
    >
    >     Thanks for the patch. Looks good in general, but it's not a fix.
    The driver
    >     does not write this register anywhere else and the reset default
    value is
    >     0x00. So we don't corrupt any other settings since, 0x00 and
    BIT(3) are the
    >     only two settings the driver does at the moment.
    >
    >     If the patch is in preparation of future changes that are going to
    set/clear
    >     other bits of the register this should be noted in the commit message.
    >
    >     The reason I'm so pedantic here is because fix generally means
    that the
    >     patch needs to be backported to older kernel versions, which is
    not the case
    >     here.
    >
    >     - Lars
    >
    >
    >     > ---
    >     >  drivers/iio/imu/adis16480.c | 15 +++++++++++++--
    >     >  1 file changed, 13 insertions(+), 2 deletions(-)
    >     >
    >     > diff --git a/drivers/iio/imu/adis16480.c
    b/drivers/iio/imu/adis16480.c
    >     > index b94bfd3..8473859 100644
    >     > --- a/drivers/iio/imu/adis16480.c
    >     > +++ b/drivers/iio/imu/adis16480.c
    >     > @@ -738,8 +738,19 @@ static int adis16480_stop_device(struct iio_dev
    >     *indio_dev)
    >     >
    >     >  static int adis16480_enable_irq(struct adis *adis, bool enable)
    >     >  {
    >     > -     return adis_write_reg_16(adis, ADIS16480_REG_FNCTIO_CTRL,
    >     > -             enable ? BIT(3) : 0);
    >     > +     u16 fnctio_ctrl;
    >     > +     int ret;
    >     > +
    >     > +     ret = adis_read_reg_16(adis, ADIS16480_REG_FNCTIO_CTRL,
    >     &fnctio_ctrl);
    >     > +     if (ret < 0)
    >     > +             return ret;
    >     > +
    >     > +     if (enable)
    >     > +             fnctio_ctrl |= BIT(3);
    >     > +     else
    >     > +             fnctio_ctrl &= ~BIT(3);
    >     > +
    >     > +     return adis_write_reg_16(adis, ADIS16480_REG_FNCTIO_CTRL,
    >     fnctio_ctrl);
    >     >  }
    >     >
    >     >  static int adis16480_initial_setup(struct iio_dev *indio_dev)
    >     >
    >
    >