diff mbox series

[1/2] ASoC: Intel: sst: Fallback to BYT-CR if IRQ 5 is missing

Message ID 20181222144708.121732-1-stephan@gerhold.net (mailing list archive)
State New, archived
Headers show
Series [1/2] ASoC: Intel: sst: Fallback to BYT-CR if IRQ 5 is missing | expand

Commit Message

Stephan Gerhold Dec. 22, 2018, 2:47 p.m. UTC
Some devices detected as BYT-T by the PMIC-type based detection
have only a single IRQ listed in the 80860F28 ACPI device. This
causes -ENXIO later when attempting to get the IRQ at index 5.
It turns out these devices behave more like BYT-CR devices,
and using the IRQ at index 0 makes sound work correctly.

This patch adds a fallback for these devices to is_byt_cr():
If there is no IRQ resource at index 5, treating the device
as BYT-T is guaranteed to fail later, so we can safely treat
these devices as BYT-CR without breaking any working device.

Link: http://mailman.alsa-project.org/pipermail/alsa-devel/2018-December/143176.html
Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
---
Moved the "Detected Baytrail-CR platform" message to is_byt_cr()
so we can log a different message if the fallback is used.

Tested this on my device as-is, and simulated a "normal"
BYT-T and BYT-CR device (copied their IRQs to a custom DSDT).

 sound/soc/intel/atom/sst/sst_acpi.c | 24 ++++++++++++++++++------
 1 file changed, 18 insertions(+), 6 deletions(-)

Comments

Pierre-Louis Bossart Dec. 31, 2018, 3:38 p.m. UTC | #1
On 12/22/18 8:47 AM, Stephan Gerhold wrote:
> Some devices detected as BYT-T by the PMIC-type based detection
> have only a single IRQ listed in the 80860F28 ACPI device. This
> causes -ENXIO later when attempting to get the IRQ at index 5.
> It turns out these devices behave more like BYT-CR devices,
> and using the IRQ at index 0 makes sound work correctly.
>
> This patch adds a fallback for these devices to is_byt_cr():
> If there is no IRQ resource at index 5, treating the device
> as BYT-T is guaranteed to fail later, so we can safely treat
> these devices as BYT-CR without breaking any working device.
>
> Link: http://mailman.alsa-project.org/pipermail/alsa-devel/2018-December/143176.html
> Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
> ---
> Moved the "Detected Baytrail-CR platform" message to is_byt_cr()
> so we can log a different message if the fallback is used.
>
> Tested this on my device as-is, and simulated a "normal"
> BYT-T and BYT-CR device (copied their IRQs to a custom DSDT).
>
>   sound/soc/intel/atom/sst/sst_acpi.c | 24 ++++++++++++++++++------
>   1 file changed, 18 insertions(+), 6 deletions(-)
>
> diff --git a/sound/soc/intel/atom/sst/sst_acpi.c b/sound/soc/intel/atom/sst/sst_acpi.c
> index 3a95ebbfc45d..755a396121ff 100644
> --- a/sound/soc/intel/atom/sst/sst_acpi.c
> +++ b/sound/soc/intel/atom/sst/sst_acpi.c
> @@ -255,10 +255,22 @@ static int is_byt(void)
>   	return status;
>   }
>   
> -static int is_byt_cr(struct device *dev, bool *bytcr)
> +static int is_byt_cr(struct platform_device *pdev, bool *bytcr)
>   {
> +	struct device *dev = &pdev->dev;
>   	int status = 0;
>   
> +	if (platform_get_resource(pdev, IORESOURCE_IRQ, 5) == NULL) {
> +		/*
> +		 * Some devices detected as BYT-T have only a single IRQ listed,
> +		 * causing platform_get_irq with index 5 to return -ENXIO.
> +		 * The correct IRQ in this case is at index 0, as used on BYT-CR.
> +		 */
> +		dev_info(dev, "Falling back to Baytrail-CR platform\n");
> +		*bytcr = true;
> +		return status;
> +	}
> +

Isn't this going to bypass the PMIC-based detection on all BYT-CR 
devices? Maybe move this code as a fallback used when the PMIC-based 
detection isn't positive?


>   	if (IS_ENABLED(CONFIG_IOSF_MBI)) {
>   		u32 bios_status;
>   
> @@ -278,10 +290,12 @@ static int is_byt_cr(struct device *dev, bool *bytcr)
>   			/* bits 26:27 mirror PMIC options */
>   			bios_status = (bios_status >> 26) & 3;
>   
> -			if ((bios_status == 1) || (bios_status == 3))
> +			if ((bios_status == 1) || (bios_status == 3)) {
> +				dev_info(dev, "Detected Baytrail-CR platform\n");
>   				*bytcr = true;
> -			else
> +			} else {
>   				dev_info(dev, "BYT-CR not detected\n");
> +			}
>   		}
>   	} else {
>   		dev_info(dev, "IOSF_MBI not enabled, no BYT-CR detection\n");
> @@ -333,10 +347,8 @@ static int sst_acpi_probe(struct platform_device *pdev)
>   	if (ret < 0)
>   		return ret;
>   
> -	ret = is_byt_cr(dev, &bytcr);
> +	ret = is_byt_cr(pdev, &bytcr);
>   	if (!(ret < 0 || !bytcr)) {
> -		dev_info(dev, "Detected Baytrail-CR platform\n");
> -
>   		/* override resource info */
>   		byt_rvp_platform_data.res_info = &bytcr_res_info;
>   	}
Stephan Gerhold Dec. 31, 2018, 4:30 p.m. UTC | #2
On Mon, Dec 31, 2018 at 09:38:21AM -0600, Pierre-Louis Bossart wrote:
> 
> On 12/22/18 8:47 AM, Stephan Gerhold wrote:
> > Some devices detected as BYT-T by the PMIC-type based detection
> > have only a single IRQ listed in the 80860F28 ACPI device. This
> > causes -ENXIO later when attempting to get the IRQ at index 5.
> > It turns out these devices behave more like BYT-CR devices,
> > and using the IRQ at index 0 makes sound work correctly.
> > 
> > This patch adds a fallback for these devices to is_byt_cr():
> > If there is no IRQ resource at index 5, treating the device
> > as BYT-T is guaranteed to fail later, so we can safely treat
> > these devices as BYT-CR without breaking any working device.
> > 
> > Link: http://mailman.alsa-project.org/pipermail/alsa-devel/2018-December/143176.html
> > Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
> > ---
> > Moved the "Detected Baytrail-CR platform" message to is_byt_cr()
> > so we can log a different message if the fallback is used.
> > 
> > Tested this on my device as-is, and simulated a "normal"
> > BYT-T and BYT-CR device (copied their IRQs to a custom DSDT).
> > 
> >   sound/soc/intel/atom/sst/sst_acpi.c | 24 ++++++++++++++++++------
> >   1 file changed, 18 insertions(+), 6 deletions(-)
> > 
> > diff --git a/sound/soc/intel/atom/sst/sst_acpi.c b/sound/soc/intel/atom/sst/sst_acpi.c
> > index 3a95ebbfc45d..755a396121ff 100644
> > --- a/sound/soc/intel/atom/sst/sst_acpi.c
> > +++ b/sound/soc/intel/atom/sst/sst_acpi.c
> > @@ -255,10 +255,22 @@ static int is_byt(void)
> >   	return status;
> >   }
> > -static int is_byt_cr(struct device *dev, bool *bytcr)
> > +static int is_byt_cr(struct platform_device *pdev, bool *bytcr)
> >   {
> > +	struct device *dev = &pdev->dev;
> >   	int status = 0;
> > +	if (platform_get_resource(pdev, IORESOURCE_IRQ, 5) == NULL) {
> > +		/*
> > +		 * Some devices detected as BYT-T have only a single IRQ listed,
> > +		 * causing platform_get_irq with index 5 to return -ENXIO.
> > +		 * The correct IRQ in this case is at index 0, as used on BYT-CR.
> > +		 */
> > +		dev_info(dev, "Falling back to Baytrail-CR platform\n");
> > +		*bytcr = true;
> > +		return status;
> > +	}
> > +
> 
> Isn't this going to bypass the PMIC-based detection on all BYT-CR devices?
> Maybe move this code as a fallback used when the PMIC-based detection isn't
> positive?
> 

Except for the message that is logged, it does not really make a 
difference. PMIC-based detection is still used for most BYT-CR devices, 
which usually have 6 IRQs listed. For the few that have not, the end 
result (bytcr = true) is the same, even if they now use the fallback.

I mentioned this in a previous mail when I asked you which option you 
would prefer (see [1]). Since is_byt_cr() has multiple returns,
I cannot just put it last without refactoring the entire method.
(Which is something I wanted to avoid...)

[1]: http://mailman.alsa-project.org/pipermail/alsa-devel/2018-December/143339.html

> 
> >   	if (IS_ENABLED(CONFIG_IOSF_MBI)) {
> >   		u32 bios_status;
> > @@ -278,10 +290,12 @@ static int is_byt_cr(struct device *dev, bool *bytcr)
> >   			/* bits 26:27 mirror PMIC options */
> >   			bios_status = (bios_status >> 26) & 3;
> > -			if ((bios_status == 1) || (bios_status == 3))
> > +			if ((bios_status == 1) || (bios_status == 3)) {
> > +				dev_info(dev, "Detected Baytrail-CR platform\n");
> >   				*bytcr = true;
> > -			else
> > +			} else {
> >   				dev_info(dev, "BYT-CR not detected\n");
> > +			}
> >   		}
> >   	} else {
> >   		dev_info(dev, "IOSF_MBI not enabled, no BYT-CR detection\n");
> > @@ -333,10 +347,8 @@ static int sst_acpi_probe(struct platform_device *pdev)
> >   	if (ret < 0)
> >   		return ret;
> > -	ret = is_byt_cr(dev, &bytcr);
> > +	ret = is_byt_cr(pdev, &bytcr);
> >   	if (!(ret < 0 || !bytcr)) {
> > -		dev_info(dev, "Detected Baytrail-CR platform\n");
> > -
> >   		/* override resource info */
> >   		byt_rvp_platform_data.res_info = &bytcr_res_info;
> >   	}
Pierre-Louis Bossart Dec. 31, 2018, 8:44 p.m. UTC | #3
On 12/31/18 10:30 AM, Stephan Gerhold wrote:
> On Mon, Dec 31, 2018 at 09:38:21AM -0600, Pierre-Louis Bossart wrote:
>> On 12/22/18 8:47 AM, Stephan Gerhold wrote:
>>> Some devices detected as BYT-T by the PMIC-type based detection
>>> have only a single IRQ listed in the 80860F28 ACPI device. This
>>> causes -ENXIO later when attempting to get the IRQ at index 5.
>>> It turns out these devices behave more like BYT-CR devices,
>>> and using the IRQ at index 0 makes sound work correctly.
>>>
>>> This patch adds a fallback for these devices to is_byt_cr():
>>> If there is no IRQ resource at index 5, treating the device
>>> as BYT-T is guaranteed to fail later, so we can safely treat
>>> these devices as BYT-CR without breaking any working device.
>>>
>>> Link: http://mailman.alsa-project.org/pipermail/alsa-devel/2018-December/143176.html
>>> Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
>>> ---
>>> Moved the "Detected Baytrail-CR platform" message to is_byt_cr()
>>> so we can log a different message if the fallback is used.
>>>
>>> Tested this on my device as-is, and simulated a "normal"
>>> BYT-T and BYT-CR device (copied their IRQs to a custom DSDT).
>>>
>>>    sound/soc/intel/atom/sst/sst_acpi.c | 24 ++++++++++++++++++------
>>>    1 file changed, 18 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/sound/soc/intel/atom/sst/sst_acpi.c b/sound/soc/intel/atom/sst/sst_acpi.c
>>> index 3a95ebbfc45d..755a396121ff 100644
>>> --- a/sound/soc/intel/atom/sst/sst_acpi.c
>>> +++ b/sound/soc/intel/atom/sst/sst_acpi.c
>>> @@ -255,10 +255,22 @@ static int is_byt(void)
>>>    	return status;
>>>    }
>>> -static int is_byt_cr(struct device *dev, bool *bytcr)
>>> +static int is_byt_cr(struct platform_device *pdev, bool *bytcr)
>>>    {
>>> +	struct device *dev = &pdev->dev;
>>>    	int status = 0;
>>> +	if (platform_get_resource(pdev, IORESOURCE_IRQ, 5) == NULL) {
>>> +		/*
>>> +		 * Some devices detected as BYT-T have only a single IRQ listed,
>>> +		 * causing platform_get_irq with index 5 to return -ENXIO.
>>> +		 * The correct IRQ in this case is at index 0, as used on BYT-CR.
>>> +		 */
>>> +		dev_info(dev, "Falling back to Baytrail-CR platform\n");
>>> +		*bytcr = true;
>>> +		return status;
>>> +	}
>>> +
>> Isn't this going to bypass the PMIC-based detection on all BYT-CR devices?
>> Maybe move this code as a fallback used when the PMIC-based detection isn't
>> positive?
>>
> Except for the message that is logged, it does not really make a
> difference. PMIC-based detection is still used for most BYT-CR devices,
> which usually have 6 IRQs listed. For the few that have not, the end
> result (bytcr = true) is the same, even if they now use the fallback.
>
> I mentioned this in a previous mail when I asked you which option you
> would prefer (see [1]). Since is_byt_cr() has multiple returns,
> I cannot just put it last without refactoring the entire method.
> (Which is something I wanted to avoid...)

Ah yes, but there was a side thread with Andy Shevchenko where we 
discussed that the initial return can be simplified since there are 
wrappers for iosf_mbi_available even when CONFIG_IOSF_MBI is not 
enabled. The code could be something like

diff --git a/sound/soc/intel/atom/sst/sst_acpi.c 
b/sound/soc/intel/atom/sst/sst_acpi.c
index ac542535b9d5..58e389a64c6a 100644
--- a/sound/soc/intel/atom/sst/sst_acpi.c
+++ b/sound/soc/intel/atom/sst/sst_acpi.c
@@ -255,17 +255,16 @@ static int is_byt(void)
         return status;
  }

-static int is_byt_cr(struct device *dev, bool *bytcr)
+static int is_byt_cr(struct platform_device *pdev, bool *bytcr)
  {
+       struct device *dev = &pdev->dev;
+       u32 bios_status;
         int status = 0;

-       if (IS_ENABLED(CONFIG_IOSF_MBI)) {
-               u32 bios_status;
+       if (!is_byt())
+               return status;

-               if (!is_byt() || !iosf_mbi_available()) {
-                       /* bail silently */
-                       return status;
-               }
+       if (iosf_mbi_available()) {

                 status = iosf_mbi_read(BT_MBI_UNIT_PMC, /* 0x04 PUNIT */
                                        MBI_REG_READ, /* 0x10 */
@@ -286,6 +285,20 @@ static int is_byt_cr(struct device *dev, bool *bytcr)
         } else {
                 dev_info(dev, "IOSF_MBI not enabled, no BYT-CR 
detection\n");
         }
+
+       if (*bytcr == false &&
+           platform_get_resource(pdev, IORESOURCE_IRQ, 5) == NULL) {
+               /*
+                * Some devices detected as BYT-T have only a single IRQ 
listed,
+                * causing platform_get_irq with index 5 to return -ENXIO.
+                * The correct IRQ in this case is at index 0, as used on
+                * BYT-CR.
+                */
+               dev_info(dev, "Falling back to Baytrail-CR platform\n");
+               status = 0;
+               *bytcr = true;
+       }
+
         return status;
  }




>
> [1]: http://mailman.alsa-project.org/pipermail/alsa-devel/2018-December/143339.html
>
>>>    	if (IS_ENABLED(CONFIG_IOSF_MBI)) {
>>>    		u32 bios_status;
>>> @@ -278,10 +290,12 @@ static int is_byt_cr(struct device *dev, bool *bytcr)
>>>    			/* bits 26:27 mirror PMIC options */
>>>    			bios_status = (bios_status >> 26) & 3;
>>> -			if ((bios_status == 1) || (bios_status == 3))
>>> +			if ((bios_status == 1) || (bios_status == 3)) {
>>> +				dev_info(dev, "Detected Baytrail-CR platform\n");
>>>    				*bytcr = true;
>>> -			else
>>> +			} else {
>>>    				dev_info(dev, "BYT-CR not detected\n");
>>> +			}
>>>    		}
>>>    	} else {
>>>    		dev_info(dev, "IOSF_MBI not enabled, no BYT-CR detection\n");
>>> @@ -333,10 +347,8 @@ static int sst_acpi_probe(struct platform_device *pdev)
>>>    	if (ret < 0)
>>>    		return ret;
>>> -	ret = is_byt_cr(dev, &bytcr);
>>> +	ret = is_byt_cr(pdev, &bytcr);
>>>    	if (!(ret < 0 || !bytcr)) {
>>> -		dev_info(dev, "Detected Baytrail-CR platform\n");
>>> -
>>>    		/* override resource info */
>>>    		byt_rvp_platform_data.res_info = &bytcr_res_info;
>>>    	}
> _______________________________________________
> Alsa-devel mailing list
> Alsa-devel@alsa-project.org
> http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
Stephan Gerhold Jan. 1, 2019, 9:11 p.m. UTC | #4
On Mon, Dec 31, 2018 at 02:44:58PM -0600, Pierre-Louis Bossart wrote:
> 
> On 12/31/18 10:30 AM, Stephan Gerhold wrote:
> > On Mon, Dec 31, 2018 at 09:38:21AM -0600, Pierre-Louis Bossart wrote:
> > > On 12/22/18 8:47 AM, Stephan Gerhold wrote:
> > > > Some devices detected as BYT-T by the PMIC-type based detection
> > > > have only a single IRQ listed in the 80860F28 ACPI device. This
> > > > causes -ENXIO later when attempting to get the IRQ at index 5.
> > > > It turns out these devices behave more like BYT-CR devices,
> > > > and using the IRQ at index 0 makes sound work correctly.
> > > > 
> > > > This patch adds a fallback for these devices to is_byt_cr():
> > > > If there is no IRQ resource at index 5, treating the device
> > > > as BYT-T is guaranteed to fail later, so we can safely treat
> > > > these devices as BYT-CR without breaking any working device.
> > > > 
> > > > Link: http://mailman.alsa-project.org/pipermail/alsa-devel/2018-December/143176.html
> > > > Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
> > > > ---
> > > > Moved the "Detected Baytrail-CR platform" message to is_byt_cr()
> > > > so we can log a different message if the fallback is used.
> > > > 
> > > > Tested this on my device as-is, and simulated a "normal"
> > > > BYT-T and BYT-CR device (copied their IRQs to a custom DSDT).
> > > > 
> > > >    sound/soc/intel/atom/sst/sst_acpi.c | 24 ++++++++++++++++++------
> > > >    1 file changed, 18 insertions(+), 6 deletions(-)
> > > > 
> > > > diff --git a/sound/soc/intel/atom/sst/sst_acpi.c b/sound/soc/intel/atom/sst/sst_acpi.c
> > > > index 3a95ebbfc45d..755a396121ff 100644
> > > > --- a/sound/soc/intel/atom/sst/sst_acpi.c
> > > > +++ b/sound/soc/intel/atom/sst/sst_acpi.c
> > > > @@ -255,10 +255,22 @@ static int is_byt(void)
> > > >    	return status;
> > > >    }
> > > > -static int is_byt_cr(struct device *dev, bool *bytcr)
> > > > +static int is_byt_cr(struct platform_device *pdev, bool *bytcr)
> > > >    {
> > > > +	struct device *dev = &pdev->dev;
> > > >    	int status = 0;
> > > > +	if (platform_get_resource(pdev, IORESOURCE_IRQ, 5) == NULL) {
> > > > +		/*
> > > > +		 * Some devices detected as BYT-T have only a single IRQ listed,
> > > > +		 * causing platform_get_irq with index 5 to return -ENXIO.
> > > > +		 * The correct IRQ in this case is at index 0, as used on BYT-CR.
> > > > +		 */
> > > > +		dev_info(dev, "Falling back to Baytrail-CR platform\n");
> > > > +		*bytcr = true;
> > > > +		return status;
> > > > +	}
> > > > +
> > > Isn't this going to bypass the PMIC-based detection on all BYT-CR devices?
> > > Maybe move this code as a fallback used when the PMIC-based detection isn't
> > > positive?
> > > 
> > Except for the message that is logged, it does not really make a
> > difference. PMIC-based detection is still used for most BYT-CR devices,
> > which usually have 6 IRQs listed. For the few that have not, the end
> > result (bytcr = true) is the same, even if they now use the fallback.
> > 
> > I mentioned this in a previous mail when I asked you which option you
> > would prefer (see [1]). Since is_byt_cr() has multiple returns,
> > I cannot just put it last without refactoring the entire method.
> > (Which is something I wanted to avoid...)
> 
> Ah yes, but there was a side thread with Andy Shevchenko where we discussed
> that the initial return can be simplified since there are wrappers for
> iosf_mbi_available even when CONFIG_IOSF_MBI is not enabled. The code could
> be something like
> 
> diff --git a/sound/soc/intel/atom/sst/sst_acpi.c
> b/sound/soc/intel/atom/sst/sst_acpi.c
> index ac542535b9d5..58e389a64c6a 100644
> --- a/sound/soc/intel/atom/sst/sst_acpi.c
> +++ b/sound/soc/intel/atom/sst/sst_acpi.c
> @@ -255,17 +255,16 @@ static int is_byt(void)
>         return status;
>  }
> 
> -static int is_byt_cr(struct device *dev, bool *bytcr)
> +static int is_byt_cr(struct platform_device *pdev, bool *bytcr)
>  {
> +       struct device *dev = &pdev->dev;
> +       u32 bios_status;
>         int status = 0;
> 
> -       if (IS_ENABLED(CONFIG_IOSF_MBI)) {
> -               u32 bios_status;
> +       if (!is_byt())
> +               return status;
> 
> -               if (!is_byt() || !iosf_mbi_available()) {
> -                       /* bail silently */
> -                       return status;
> -               }
> +       if (iosf_mbi_available()) {
> 
>                 status = iosf_mbi_read(BT_MBI_UNIT_PMC, /* 0x04 PUNIT */
>                                        MBI_REG_READ, /* 0x10 */
> @@ -286,6 +285,20 @@ static int is_byt_cr(struct device *dev, bool *bytcr)
>         } else {
>                 dev_info(dev, "IOSF_MBI not enabled, no BYT-CR
> detection\n");
>         }
> +
> +       if (*bytcr == false &&
> +           platform_get_resource(pdev, IORESOURCE_IRQ, 5) == NULL) {
> +               /*
> +                * Some devices detected as BYT-T have only a single IRQ
> listed,
> +                * causing platform_get_irq with index 5 to return -ENXIO.
> +                * The correct IRQ in this case is at index 0, as used on
> +                * BYT-CR.
> +                */
> +               dev_info(dev, "Falling back to Baytrail-CR platform\n");
> +               status = 0;
> +               *bytcr = true;
> +       }
> +
>         return status;
>  }
> 
> 

Thanks! That looks fine to me. I will test it on my device and send a v2 
shortly.

Speaking of simplifying is_byt_cr(): Especially its usage in

	ret = is_byt_cr(pdev, &bytcr);
	if (!(ret < 0 || !bytcr)) {
		/* override resource info */
		byt_rvp_platform_data.res_info = &bytcr_res_info;
	}

with the negated "or" has been rather confusing to read for me.
In my opinion, it would be easier to understand as:
	if (ret == 0 && bytcr)

The return value (`ret`) is only used in this if statement.
Since `bytcr` stays false when an error occurs in is_byt_cr(),
we could further simplify this by returning the bool directly:
	if (is_byt_cr(pdev))

Together with:

static bool is_byt_cr(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;

	if (!is_byt())
		return false;

	if (iosf_mbi_available()) {
		u32 bios_status;
		int status = iosf_mbi_read(BT_MBI_UNIT_PMC, /* 0x04 PUNIT */
				       MBI_REG_READ, /* 0x10 */
				       0x006, /* BIOS_CONFIG */
				       &bios_status);

		if (status) {
			dev_err(dev, "could not read PUNIT BIOS_CONFIG\n");
		} else {
			/* bits 26:27 mirror PMIC options */
			bios_status = (bios_status >> 26) & 3;

			if ((bios_status == 1) || (bios_status == 3)) {
				dev_info(dev, "Detected Baytrail-CR platform\n");
				return true;
			} else {
				dev_info(dev, "BYT-CR not detected\n");
			}
		}
	} else {
		dev_info(dev, "IOSF_MBI not enabled, no BYT-CR detection\n");
	}

	if (platform_get_resource(pdev, IORESOURCE_IRQ, 5) == NULL) {
		/*
		 * Some devices detected as BYT-T have only a single IRQ listed,
		 * causing platform_get_irq with index 5 to return -ENXIO.
		 * The correct IRQ in this case is at index 0, as used on BYT-CR.
		 */
		dev_info(dev, "Falling back to Baytrail-CR platform\n");
		return true;
	}

	return false;
}

What do you think?

> 
> 
> > 
> > [1]: http://mailman.alsa-project.org/pipermail/alsa-devel/2018-December/143339.html
> > 
> > > >    	if (IS_ENABLED(CONFIG_IOSF_MBI)) {
> > > >    		u32 bios_status;
> > > > @@ -278,10 +290,12 @@ static int is_byt_cr(struct device *dev, bool *bytcr)
> > > >    			/* bits 26:27 mirror PMIC options */
> > > >    			bios_status = (bios_status >> 26) & 3;
> > > > -			if ((bios_status == 1) || (bios_status == 3))
> > > > +			if ((bios_status == 1) || (bios_status == 3)) {
> > > > +				dev_info(dev, "Detected Baytrail-CR platform\n");
> > > >    				*bytcr = true;
> > > > -			else
> > > > +			} else {
> > > >    				dev_info(dev, "BYT-CR not detected\n");
> > > > +			}
> > > >    		}
> > > >    	} else {
> > > >    		dev_info(dev, "IOSF_MBI not enabled, no BYT-CR detection\n");
> > > > @@ -333,10 +347,8 @@ static int sst_acpi_probe(struct platform_device *pdev)
> > > >    	if (ret < 0)
> > > >    		return ret;
> > > > -	ret = is_byt_cr(dev, &bytcr);
> > > > +	ret = is_byt_cr(pdev, &bytcr);
> > > >    	if (!(ret < 0 || !bytcr)) {
> > > > -		dev_info(dev, "Detected Baytrail-CR platform\n");
> > > > -
> > > >    		/* override resource info */
> > > >    		byt_rvp_platform_data.res_info = &bytcr_res_info;
> > > >    	}
> > _______________________________________________
> > Alsa-devel mailing list
> > Alsa-devel@alsa-project.org
> > http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
Pierre-Louis Bossart Jan. 2, 2019, 4:39 p.m. UTC | #5
On 1/1/19 3:11 PM, Stephan Gerhold wrote:
> On Mon, Dec 31, 2018 at 02:44:58PM -0600, Pierre-Louis Bossart wrote:
>> On 12/31/18 10:30 AM, Stephan Gerhold wrote:
>>> On Mon, Dec 31, 2018 at 09:38:21AM -0600, Pierre-Louis Bossart wrote:
>>>> On 12/22/18 8:47 AM, Stephan Gerhold wrote:
>>>>> Some devices detected as BYT-T by the PMIC-type based detection
>>>>> have only a single IRQ listed in the 80860F28 ACPI device. This
>>>>> causes -ENXIO later when attempting to get the IRQ at index 5.
>>>>> It turns out these devices behave more like BYT-CR devices,
>>>>> and using the IRQ at index 0 makes sound work correctly.
>>>>>
>>>>> This patch adds a fallback for these devices to is_byt_cr():
>>>>> If there is no IRQ resource at index 5, treating the device
>>>>> as BYT-T is guaranteed to fail later, so we can safely treat
>>>>> these devices as BYT-CR without breaking any working device.
>>>>>
>>>>> Link: http://mailman.alsa-project.org/pipermail/alsa-devel/2018-December/143176.html
>>>>> Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
>>>>> ---
>>>>> Moved the "Detected Baytrail-CR platform" message to is_byt_cr()
>>>>> so we can log a different message if the fallback is used.
>>>>>
>>>>> Tested this on my device as-is, and simulated a "normal"
>>>>> BYT-T and BYT-CR device (copied their IRQs to a custom DSDT).
>>>>>
>>>>>     sound/soc/intel/atom/sst/sst_acpi.c | 24 ++++++++++++++++++------
>>>>>     1 file changed, 18 insertions(+), 6 deletions(-)
>>>>>
>>>>> diff --git a/sound/soc/intel/atom/sst/sst_acpi.c b/sound/soc/intel/atom/sst/sst_acpi.c
>>>>> index 3a95ebbfc45d..755a396121ff 100644
>>>>> --- a/sound/soc/intel/atom/sst/sst_acpi.c
>>>>> +++ b/sound/soc/intel/atom/sst/sst_acpi.c
>>>>> @@ -255,10 +255,22 @@ static int is_byt(void)
>>>>>     	return status;
>>>>>     }
>>>>> -static int is_byt_cr(struct device *dev, bool *bytcr)
>>>>> +static int is_byt_cr(struct platform_device *pdev, bool *bytcr)
>>>>>     {
>>>>> +	struct device *dev = &pdev->dev;
>>>>>     	int status = 0;
>>>>> +	if (platform_get_resource(pdev, IORESOURCE_IRQ, 5) == NULL) {
>>>>> +		/*
>>>>> +		 * Some devices detected as BYT-T have only a single IRQ listed,
>>>>> +		 * causing platform_get_irq with index 5 to return -ENXIO.
>>>>> +		 * The correct IRQ in this case is at index 0, as used on BYT-CR.
>>>>> +		 */
>>>>> +		dev_info(dev, "Falling back to Baytrail-CR platform\n");
>>>>> +		*bytcr = true;
>>>>> +		return status;
>>>>> +	}
>>>>> +
>>>> Isn't this going to bypass the PMIC-based detection on all BYT-CR devices?
>>>> Maybe move this code as a fallback used when the PMIC-based detection isn't
>>>> positive?
>>>>
>>> Except for the message that is logged, it does not really make a
>>> difference. PMIC-based detection is still used for most BYT-CR devices,
>>> which usually have 6 IRQs listed. For the few that have not, the end
>>> result (bytcr = true) is the same, even if they now use the fallback.
>>>
>>> I mentioned this in a previous mail when I asked you which option you
>>> would prefer (see [1]). Since is_byt_cr() has multiple returns,
>>> I cannot just put it last without refactoring the entire method.
>>> (Which is something I wanted to avoid...)
>> Ah yes, but there was a side thread with Andy Shevchenko where we discussed
>> that the initial return can be simplified since there are wrappers for
>> iosf_mbi_available even when CONFIG_IOSF_MBI is not enabled. The code could
>> be something like
>>
>> diff --git a/sound/soc/intel/atom/sst/sst_acpi.c
>> b/sound/soc/intel/atom/sst/sst_acpi.c
>> index ac542535b9d5..58e389a64c6a 100644
>> --- a/sound/soc/intel/atom/sst/sst_acpi.c
>> +++ b/sound/soc/intel/atom/sst/sst_acpi.c
>> @@ -255,17 +255,16 @@ static int is_byt(void)
>>          return status;
>>   }
>>
>> -static int is_byt_cr(struct device *dev, bool *bytcr)
>> +static int is_byt_cr(struct platform_device *pdev, bool *bytcr)
>>   {
>> +       struct device *dev = &pdev->dev;
>> +       u32 bios_status;
>>          int status = 0;
>>
>> -       if (IS_ENABLED(CONFIG_IOSF_MBI)) {
>> -               u32 bios_status;
>> +       if (!is_byt())
>> +               return status;
>>
>> -               if (!is_byt() || !iosf_mbi_available()) {
>> -                       /* bail silently */
>> -                       return status;
>> -               }
>> +       if (iosf_mbi_available()) {
>>
>>                  status = iosf_mbi_read(BT_MBI_UNIT_PMC, /* 0x04 PUNIT */
>>                                         MBI_REG_READ, /* 0x10 */
>> @@ -286,6 +285,20 @@ static int is_byt_cr(struct device *dev, bool *bytcr)
>>          } else {
>>                  dev_info(dev, "IOSF_MBI not enabled, no BYT-CR
>> detection\n");
>>          }
>> +
>> +       if (*bytcr == false &&
>> +           platform_get_resource(pdev, IORESOURCE_IRQ, 5) == NULL) {
>> +               /*
>> +                * Some devices detected as BYT-T have only a single IRQ
>> listed,
>> +                * causing platform_get_irq with index 5 to return -ENXIO.
>> +                * The correct IRQ in this case is at index 0, as used on
>> +                * BYT-CR.
>> +                */
>> +               dev_info(dev, "Falling back to Baytrail-CR platform\n");
>> +               status = 0;
>> +               *bytcr = true;
>> +       }
>> +
>>          return status;
>>   }
>>
>>
> Thanks! That looks fine to me. I will test it on my device and send a v2
> shortly.
>
> Speaking of simplifying is_byt_cr(): Especially its usage in
>
> 	ret = is_byt_cr(pdev, &bytcr);
> 	if (!(ret < 0 || !bytcr)) {
> 		/* override resource info */
> 		byt_rvp_platform_data.res_info = &bytcr_res_info;
> 	}
>
> with the negated "or" has been rather confusing to read for me.
> In my opinion, it would be easier to understand as:
> 	if (ret == 0 && bytcr)
>
> The return value (`ret`) is only used in this if statement.
> Since `bytcr` stays false when an error occurs in is_byt_cr(),
> we could further simplify this by returning the bool directly:
> 	if (is_byt_cr(pdev))

I like the suggested changes. This code evolved over time, IIRC the 
status was initially reporting some ACPI code but now a boolean will do. 
Good discussion, thanks!


>
> Together with:
>
> static bool is_byt_cr(struct platform_device *pdev)
> {
> 	struct device *dev = &pdev->dev;
>
> 	if (!is_byt())
> 		return false;
>
> 	if (iosf_mbi_available()) {
> 		u32 bios_status;
> 		int status = iosf_mbi_read(BT_MBI_UNIT_PMC, /* 0x04 PUNIT */
> 				       MBI_REG_READ, /* 0x10 */
> 				       0x006, /* BIOS_CONFIG */
> 				       &bios_status);
>
> 		if (status) {
> 			dev_err(dev, "could not read PUNIT BIOS_CONFIG\n");
> 		} else {
> 			/* bits 26:27 mirror PMIC options */
> 			bios_status = (bios_status >> 26) & 3;
>
> 			if ((bios_status == 1) || (bios_status == 3)) {
> 				dev_info(dev, "Detected Baytrail-CR platform\n");
> 				return true;
> 			} else {
> 				dev_info(dev, "BYT-CR not detected\n");
> 			}
> 		}
> 	} else {
> 		dev_info(dev, "IOSF_MBI not enabled, no BYT-CR detection\n");
> 	}
>
> 	if (platform_get_resource(pdev, IORESOURCE_IRQ, 5) == NULL) {
> 		/*
> 		 * Some devices detected as BYT-T have only a single IRQ listed,
> 		 * causing platform_get_irq with index 5 to return -ENXIO.
> 		 * The correct IRQ in this case is at index 0, as used on BYT-CR.
> 		 */
> 		dev_info(dev, "Falling back to Baytrail-CR platform\n");
> 		return true;
> 	}
>
> 	return false;
> }
>
> What do you think?
>
>>
>>> [1]: http://mailman.alsa-project.org/pipermail/alsa-devel/2018-December/143339.html
>>>
>>>>>     	if (IS_ENABLED(CONFIG_IOSF_MBI)) {
>>>>>     		u32 bios_status;
>>>>> @@ -278,10 +290,12 @@ static int is_byt_cr(struct device *dev, bool *bytcr)
>>>>>     			/* bits 26:27 mirror PMIC options */
>>>>>     			bios_status = (bios_status >> 26) & 3;
>>>>> -			if ((bios_status == 1) || (bios_status == 3))
>>>>> +			if ((bios_status == 1) || (bios_status == 3)) {
>>>>> +				dev_info(dev, "Detected Baytrail-CR platform\n");
>>>>>     				*bytcr = true;
>>>>> -			else
>>>>> +			} else {
>>>>>     				dev_info(dev, "BYT-CR not detected\n");
>>>>> +			}
>>>>>     		}
>>>>>     	} else {
>>>>>     		dev_info(dev, "IOSF_MBI not enabled, no BYT-CR detection\n");
>>>>> @@ -333,10 +347,8 @@ static int sst_acpi_probe(struct platform_device *pdev)
>>>>>     	if (ret < 0)
>>>>>     		return ret;
>>>>> -	ret = is_byt_cr(dev, &bytcr);
>>>>> +	ret = is_byt_cr(pdev, &bytcr);
>>>>>     	if (!(ret < 0 || !bytcr)) {
>>>>> -		dev_info(dev, "Detected Baytrail-CR platform\n");
>>>>> -
>>>>>     		/* override resource info */
>>>>>     		byt_rvp_platform_data.res_info = &bytcr_res_info;
>>>>>     	}
>>> _______________________________________________
>>> Alsa-devel mailing list
>>> Alsa-devel@alsa-project.org
>>> http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
> _______________________________________________
> Alsa-devel mailing list
> Alsa-devel@alsa-project.org
> http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
diff mbox series

Patch

diff --git a/sound/soc/intel/atom/sst/sst_acpi.c b/sound/soc/intel/atom/sst/sst_acpi.c
index 3a95ebbfc45d..755a396121ff 100644
--- a/sound/soc/intel/atom/sst/sst_acpi.c
+++ b/sound/soc/intel/atom/sst/sst_acpi.c
@@ -255,10 +255,22 @@  static int is_byt(void)
 	return status;
 }
 
-static int is_byt_cr(struct device *dev, bool *bytcr)
+static int is_byt_cr(struct platform_device *pdev, bool *bytcr)
 {
+	struct device *dev = &pdev->dev;
 	int status = 0;
 
+	if (platform_get_resource(pdev, IORESOURCE_IRQ, 5) == NULL) {
+		/*
+		 * Some devices detected as BYT-T have only a single IRQ listed,
+		 * causing platform_get_irq with index 5 to return -ENXIO.
+		 * The correct IRQ in this case is at index 0, as used on BYT-CR.
+		 */
+		dev_info(dev, "Falling back to Baytrail-CR platform\n");
+		*bytcr = true;
+		return status;
+	}
+
 	if (IS_ENABLED(CONFIG_IOSF_MBI)) {
 		u32 bios_status;
 
@@ -278,10 +290,12 @@  static int is_byt_cr(struct device *dev, bool *bytcr)
 			/* bits 26:27 mirror PMIC options */
 			bios_status = (bios_status >> 26) & 3;
 
-			if ((bios_status == 1) || (bios_status == 3))
+			if ((bios_status == 1) || (bios_status == 3)) {
+				dev_info(dev, "Detected Baytrail-CR platform\n");
 				*bytcr = true;
-			else
+			} else {
 				dev_info(dev, "BYT-CR not detected\n");
+			}
 		}
 	} else {
 		dev_info(dev, "IOSF_MBI not enabled, no BYT-CR detection\n");
@@ -333,10 +347,8 @@  static int sst_acpi_probe(struct platform_device *pdev)
 	if (ret < 0)
 		return ret;
 
-	ret = is_byt_cr(dev, &bytcr);
+	ret = is_byt_cr(pdev, &bytcr);
 	if (!(ret < 0 || !bytcr)) {
-		dev_info(dev, "Detected Baytrail-CR platform\n");
-
 		/* override resource info */
 		byt_rvp_platform_data.res_info = &bytcr_res_info;
 	}