Re: [PATCH] ACPI / LPSS: Do not instiate a platform_dev for devs without a mmio resource

[Andy Shevchenko]

On Mon, 2018-01-15 at 11:36 +0200, Mika Westerberg wrote:
> On Sun, Jan 14, 2018 at 09:01:48PM +0100, Hans de Goede wrote:
> > acpi_lpss_create_device() skips handling LPSS devices which do not
> > have
> > a mmio resources in their resource list (typically these devices are
> > disabled by the firmware). But since the LPSS code does not bind to
> > the
> > device, acpi_bus_attach() ends up still creating a platform device
> > for
> > it and the regular platform_driver for the ACPI HID still tries to
> > bind
> > to it.
> > 
> > This happens e.g. on some boards which do not use the pwm-controller
> > and have an empty or invalid resource-table for it. Currently this
> > causes
> > these error messages to get logged:
> > [3.281966] pwm-lpss 80862288:00: invalid resource
> > [3.287098] pwm-lpss: probe of 80862288:00 failed with error -22
> > 
> > This commit stops the undesirable creation of a platform_device for
> > disabled LPSS devices by setting pnp.type.platform_id to 0. Note
> > that
> > acpi_scan_attach_handler() also sets pnp.type.platform_id to 0 when
> > there
> > is a matching handler for the device and that handler has no attach
> > callback, so we simply behave as a handler without an attach
> > function
> > in this case.
> > 
> > Signed-off-by: Hans de Goede 
> 
> Seems like a good way to fix it IMHO,

Yeah, looks much better for my opinion than previous hack to PWM
platform driver.

Reviewed-by: Andy Shevchenko 

> 
> Acked-by: Mika Westerberg 

-- 
Andy Shevchenko 
Intel Finland Oy

Re: [PATCH] ACPI / LPSS: Do not instiate a platform_dev for devs without a mmio resource

[Andy Shevchenko]

On Mon, 2018-01-15 at 11:36 +0200, Mika Westerberg wrote:
> On Sun, Jan 14, 2018 at 09:01:48PM +0100, Hans de Goede wrote:
> > acpi_lpss_create_device() skips handling LPSS devices which do not
> > have
> > a mmio resources in their resource list (typically these devices are
> > disabled by the firmware). But since the LPSS code does not bind to
> > the
> > device, acpi_bus_attach() ends up still creating a platform device
> > for
> > it and the regular platform_driver for the ACPI HID still tries to
> > bind
> > to it.
> > 
> > This happens e.g. on some boards which do not use the pwm-controller
> > and have an empty or invalid resource-table for it. Currently this
> > causes
> > these error messages to get logged:
> > [3.281966] pwm-lpss 80862288:00: invalid resource
> > [3.287098] pwm-lpss: probe of 80862288:00 failed with error -22
> > 
> > This commit stops the undesirable creation of a platform_device for
> > disabled LPSS devices by setting pnp.type.platform_id to 0. Note
> > that
> > acpi_scan_attach_handler() also sets pnp.type.platform_id to 0 when
> > there
> > is a matching handler for the device and that handler has no attach
> > callback, so we simply behave as a handler without an attach
> > function
> > in this case.
> > 
> > Signed-off-by: Hans de Goede 
> 
> Seems like a good way to fix it IMHO,

Yeah, looks much better for my opinion than previous hack to PWM
platform driver.

Reviewed-by: Andy Shevchenko 

> 
> Acked-by: Mika Westerberg 

-- 
Andy Shevchenko 
Intel Finland Oy

Re: [PATCH] ACPI / LPSS: Do not instiate a platform_dev for devs without a mmio resource

[Mika Westerberg]

On Sun, Jan 14, 2018 at 09:01:48PM +0100, Hans de Goede wrote:
> acpi_lpss_create_device() skips handling LPSS devices which do not have
> a mmio resources in their resource list (typically these devices are
> disabled by the firmware). But since the LPSS code does not bind to the
> device, acpi_bus_attach() ends up still creating a platform device for
> it and the regular platform_driver for the ACPI HID still tries to bind
> to it.
> 
> This happens e.g. on some boards which do not use the pwm-controller
> and have an empty or invalid resource-table for it. Currently this causes
> these error messages to get logged:
> [3.281966] pwm-lpss 80862288:00: invalid resource
> [3.287098] pwm-lpss: probe of 80862288:00 failed with error -22
> 
> This commit stops the undesirable creation of a platform_device for
> disabled LPSS devices by setting pnp.type.platform_id to 0. Note that
> acpi_scan_attach_handler() also sets pnp.type.platform_id to 0 when there
> is a matching handler for the device and that handler has no attach
> callback, so we simply behave as a handler without an attach function
> in this case.
> 
> Signed-off-by: Hans de Goede 

Seems like a good way to fix it IMHO,

Acked-by: Mika Westerberg 

Re: [PATCH] ACPI / LPSS: Do not instiate a platform_dev for devs without a mmio resource

[Mika Westerberg]

On Sun, Jan 14, 2018 at 09:01:48PM +0100, Hans de Goede wrote:
> acpi_lpss_create_device() skips handling LPSS devices which do not have
> a mmio resources in their resource list (typically these devices are
> disabled by the firmware). But since the LPSS code does not bind to the
> device, acpi_bus_attach() ends up still creating a platform device for
> it and the regular platform_driver for the ACPI HID still tries to bind
> to it.
> 
> This happens e.g. on some boards which do not use the pwm-controller
> and have an empty or invalid resource-table for it. Currently this causes
> these error messages to get logged:
> [3.281966] pwm-lpss 80862288:00: invalid resource
> [3.287098] pwm-lpss: probe of 80862288:00 failed with error -22
> 
> This commit stops the undesirable creation of a platform_device for
> disabled LPSS devices by setting pnp.type.platform_id to 0. Note that
> acpi_scan_attach_handler() also sets pnp.type.platform_id to 0 when there
> is a matching handler for the device and that handler has no attach
> callback, so we simply behave as a handler without an attach function
> in this case.
> 
> Signed-off-by: Hans de Goede 

Seems like a good way to fix it IMHO,

Acked-by: Mika Westerberg 

Re: [PATCH] ACPI / LPSS: Do not instiate a platform_dev for devs without a mmio resource

[Hans de Goede]

Hi,

On 15-01-18 00:36, Rafael J. Wysocki wrote:

On Sun, Jan 14, 2018 at 9:01 PM, Hans de Goede  wrote:

acpi_lpss_create_device() skips handling LPSS devices which do not have
a mmio resources in their resource list (typically these devices are
disabled by the firmware). But since the LPSS code does not bind to the
device, acpi_bus_attach() ends up still creating a platform device for
it and the regular platform_driver for the ACPI HID still tries to bind
to it.

This happens e.g. on some boards which do not use the pwm-controller
and have an empty or invalid resource-table for it. Currently this causes
these error messages to get logged:
[3.281966] pwm-lpss 80862288:00: invalid resource
[3.287098] pwm-lpss: probe of 80862288:00 failed with error -22

This commit stops the undesirable creation of a platform_device for
disabled LPSS devices by setting pnp.type.platform_id to 0. Note that
acpi_scan_attach_handler() also sets pnp.type.platform_id to 0 when there
is a matching handler for the device and that handler has no attach
callback, so we simply behave as a handler without an attach function
in this case.

Signed-off-by: Hans de Goede 


Does this fix new behavior or is it an old issue?


The problem this addresses is likely caused by the acpi_always_present
entry for the CHT 80862288 PWM devices in drivers/acpi/x86/utils.c.

The problem is that under Windows the Intel GPU driver has hardcoded
addresses for the PWM LPSS bits (or so I believe), rather then having
it as a separate device with a separate driver, so the CHT LPSS PWM
device's _STA returns 0 on all x86 devices which ship with Windows.

On most CHT laptops / tablets it is used to control the backlight
brightness so we do need the device under Linux, where we've a
separate PWM driver and we don't want to be hardcoding stuff like
this.

So we really cannot do without the acpi_always_present entry, and thus
need this extra check for devices where the pwm is actually unused
and disabled by the firmware.

Regards,

Hans


---
  drivers/acpi/acpi_lpss.c | 2 ++
  1 file changed, 2 insertions(+)

diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c
index 9cfe6b71078b..166a8e582d96 100644
--- a/drivers/acpi/acpi_lpss.c
+++ b/drivers/acpi/acpi_lpss.c
@@ -610,6 +610,8 @@ static int acpi_lpss_create_device(struct acpi_device *adev,
 acpi_dev_free_resource_list(_list);

 if (!pdata->mmio_base) {
+   /* Avoid acpi_bus_attach() instantiating a pdev for this dev. */
+   adev->pnp.type.platform_id = 0;
 /* Skip the device, but continue the namespace scan. */
 ret = 0;
 goto err_out;
--
2.14.3

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Re: [PATCH] ACPI / LPSS: Do not instiate a platform_dev for devs without a mmio resource

[Hans de Goede]

Hi,

On 15-01-18 00:36, Rafael J. Wysocki wrote:

On Sun, Jan 14, 2018 at 9:01 PM, Hans de Goede  wrote:

acpi_lpss_create_device() skips handling LPSS devices which do not have
a mmio resources in their resource list (typically these devices are
disabled by the firmware). But since the LPSS code does not bind to the
device, acpi_bus_attach() ends up still creating a platform device for
it and the regular platform_driver for the ACPI HID still tries to bind
to it.

This happens e.g. on some boards which do not use the pwm-controller
and have an empty or invalid resource-table for it. Currently this causes
these error messages to get logged:
[3.281966] pwm-lpss 80862288:00: invalid resource
[3.287098] pwm-lpss: probe of 80862288:00 failed with error -22

This commit stops the undesirable creation of a platform_device for
disabled LPSS devices by setting pnp.type.platform_id to 0. Note that
acpi_scan_attach_handler() also sets pnp.type.platform_id to 0 when there
is a matching handler for the device and that handler has no attach
callback, so we simply behave as a handler without an attach function
in this case.

Signed-off-by: Hans de Goede 


Does this fix new behavior or is it an old issue?


The problem this addresses is likely caused by the acpi_always_present
entry for the CHT 80862288 PWM devices in drivers/acpi/x86/utils.c.

The problem is that under Windows the Intel GPU driver has hardcoded
addresses for the PWM LPSS bits (or so I believe), rather then having
it as a separate device with a separate driver, so the CHT LPSS PWM
device's _STA returns 0 on all x86 devices which ship with Windows.

On most CHT laptops / tablets it is used to control the backlight
brightness so we do need the device under Linux, where we've a
separate PWM driver and we don't want to be hardcoding stuff like
this.

So we really cannot do without the acpi_always_present entry, and thus
need this extra check for devices where the pwm is actually unused
and disabled by the firmware.

Regards,

Hans


---
  drivers/acpi/acpi_lpss.c | 2 ++
  1 file changed, 2 insertions(+)

diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c
index 9cfe6b71078b..166a8e582d96 100644
--- a/drivers/acpi/acpi_lpss.c
+++ b/drivers/acpi/acpi_lpss.c
@@ -610,6 +610,8 @@ static int acpi_lpss_create_device(struct acpi_device *adev,
 acpi_dev_free_resource_list(_list);

 if (!pdata->mmio_base) {
+   /* Avoid acpi_bus_attach() instantiating a pdev for this dev. */
+   adev->pnp.type.platform_id = 0;
 /* Skip the device, but continue the namespace scan. */
 ret = 0;
 goto err_out;
--
2.14.3

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Re: [PATCH] ACPI / LPSS: Do not instiate a platform_dev for devs without a mmio resource

[Rafael J. Wysocki]

On Sun, Jan 14, 2018 at 9:01 PM, Hans de Goede  wrote:
> acpi_lpss_create_device() skips handling LPSS devices which do not have
> a mmio resources in their resource list (typically these devices are
> disabled by the firmware). But since the LPSS code does not bind to the
> device, acpi_bus_attach() ends up still creating a platform device for
> it and the regular platform_driver for the ACPI HID still tries to bind
> to it.
>
> This happens e.g. on some boards which do not use the pwm-controller
> and have an empty or invalid resource-table for it. Currently this causes
> these error messages to get logged:
> [3.281966] pwm-lpss 80862288:00: invalid resource
> [3.287098] pwm-lpss: probe of 80862288:00 failed with error -22
>
> This commit stops the undesirable creation of a platform_device for
> disabled LPSS devices by setting pnp.type.platform_id to 0. Note that
> acpi_scan_attach_handler() also sets pnp.type.platform_id to 0 when there
> is a matching handler for the device and that handler has no attach
> callback, so we simply behave as a handler without an attach function
> in this case.
>
> Signed-off-by: Hans de Goede 

Does this fix new behavior or is it an old issue?

> ---
>  drivers/acpi/acpi_lpss.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c
> index 9cfe6b71078b..166a8e582d96 100644
> --- a/drivers/acpi/acpi_lpss.c
> +++ b/drivers/acpi/acpi_lpss.c
> @@ -610,6 +610,8 @@ static int acpi_lpss_create_device(struct acpi_device 
> *adev,
> acpi_dev_free_resource_list(_list);
>
> if (!pdata->mmio_base) {
> +   /* Avoid acpi_bus_attach() instantiating a pdev for this dev. 
> */
> +   adev->pnp.type.platform_id = 0;
> /* Skip the device, but continue the namespace scan. */
> ret = 0;
> goto err_out;
> --
> 2.14.3
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
> the body of a message to majord...@vger.kernel.org
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Re: [PATCH] ACPI / LPSS: Do not instiate a platform_dev for devs without a mmio resource

[Rafael J. Wysocki]

On Sun, Jan 14, 2018 at 9:01 PM, Hans de Goede  wrote:
> acpi_lpss_create_device() skips handling LPSS devices which do not have
> a mmio resources in their resource list (typically these devices are
> disabled by the firmware). But since the LPSS code does not bind to the
> device, acpi_bus_attach() ends up still creating a platform device for
> it and the regular platform_driver for the ACPI HID still tries to bind
> to it.
>
> This happens e.g. on some boards which do not use the pwm-controller
> and have an empty or invalid resource-table for it. Currently this causes
> these error messages to get logged:
> [3.281966] pwm-lpss 80862288:00: invalid resource
> [3.287098] pwm-lpss: probe of 80862288:00 failed with error -22
>
> This commit stops the undesirable creation of a platform_device for
> disabled LPSS devices by setting pnp.type.platform_id to 0. Note that
> acpi_scan_attach_handler() also sets pnp.type.platform_id to 0 when there
> is a matching handler for the device and that handler has no attach
> callback, so we simply behave as a handler without an attach function
> in this case.
>
> Signed-off-by: Hans de Goede 

Does this fix new behavior or is it an old issue?

> ---
>  drivers/acpi/acpi_lpss.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c
> index 9cfe6b71078b..166a8e582d96 100644
> --- a/drivers/acpi/acpi_lpss.c
> +++ b/drivers/acpi/acpi_lpss.c
> @@ -610,6 +610,8 @@ static int acpi_lpss_create_device(struct acpi_device 
> *adev,
> acpi_dev_free_resource_list(_list);
>
> if (!pdata->mmio_base) {
> +   /* Avoid acpi_bus_attach() instantiating a pdev for this dev. 
> */
> +   adev->pnp.type.platform_id = 0;
> /* Skip the device, but continue the namespace scan. */
> ret = 0;
> goto err_out;
> --
> 2.14.3
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
> the body of a message to majord...@vger.kernel.org
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