Patchwork [Lucid,SRU] UBUNTU: SAUCE: dell-laptop: fire SMI when toggling hardware killswitch

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Submitter Keng-Yu Lin
Date June 9, 2010, 7:44 a.m.
Message ID <1276069479-28999-1-git-send-email-keng-yu.lin@canonical.com>
Download mbox | patch
Permalink /patch/55056/
State Superseded
Delegated to: Stefan Bader
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Comments

Keng-Yu Lin - June 9, 2010, 7:44 a.m.
SRU Justification:

Impact:
A type of Dell Inspiron Mini does not turn off bluetooth physically when
pressing F2 (rfkill hotkey). 

Fix: 
Current kernel code expects hardware to handle the hard-rfkill switching
spontaneously and only notify rfkill subsystem with the status change.
This patch makes kernel to explicitly fire a SMI to switch on/off
rfkill devices if BIOS reports that the hardware switch is not supported.

This patch depends on the following sauce patch in lucid kernel so is not going upstream:
	UBUNTU: SAUCE: dell-laptop: Store the HW switch status internally rather than requerying every time

Testcase: 
I tested the patch on a Dell Mini 10. It works smoothly.

--
From b17359e833677297d4d5daf78e4d9dc460e51285 Mon Sep 17 00:00:00 2001
From: Keng-Yu Lin <keng-yu.lin@canonical.com>
Date: Thu, 3 Jun 2010 10:31:56 +0800
Subject: [PATCH] UBUNTU: SAUCE: dell-laptop: fire SMI when toggling hardware killswitch

When BIOS reports hardware switch is not supported, it does not turn on/off all
devices spontaneously. So it is neccessary to fire an SMI to switch the rfkill
status explicitly when toggling the hardware killswitch.

BugLink: http://bugs.launchpad.net/bugs/590607

Signed-off-by: Keng-Yu Lin <keng-yu.lin@canonical.com>
---
 drivers/platform/x86/dell-laptop.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)
Eric Miao - June 9, 2010, 8:21 a.m.
On Wed, Jun 9, 2010 at 3:44 PM, Keng-Yu Lin <keng-yu.lin@canonical.com> wrote:
> SRU Justification:
>
> Impact:
> A type of Dell Inspiron Mini does not turn off bluetooth physically when
> pressing F2 (rfkill hotkey).
>
> Fix:
> Current kernel code expects hardware to handle the hard-rfkill switching
> spontaneously and only notify rfkill subsystem with the status change.
> This patch makes kernel to explicitly fire a SMI to switch on/off
> rfkill devices if BIOS reports that the hardware switch is not supported.
>
> This patch depends on the following sauce patch in lucid kernel so is not going upstream:
>        UBUNTU: SAUCE: dell-laptop: Store the HW switch status internally rather than requerying every time
>
> Testcase:
> I tested the patch on a Dell Mini 10. It works smoothly.
>
> --
> From b17359e833677297d4d5daf78e4d9dc460e51285 Mon Sep 17 00:00:00 2001
> From: Keng-Yu Lin <keng-yu.lin@canonical.com>
> Date: Thu, 3 Jun 2010 10:31:56 +0800
> Subject: [PATCH] UBUNTU: SAUCE: dell-laptop: fire SMI when toggling hardware killswitch
>
> When BIOS reports hardware switch is not supported, it does not turn on/off all
> devices spontaneously. So it is neccessary to fire an SMI to switch the rfkill
> status explicitly when toggling the hardware killswitch.
>
> BugLink: http://bugs.launchpad.net/bugs/590607
>
> Signed-off-by: Keng-Yu Lin <keng-yu.lin@canonical.com>
> ---
>  drivers/platform/x86/dell-laptop.c |    4 +++-
>  1 files changed, 3 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/platform/x86/dell-laptop.c b/drivers/platform/x86/dell-laptop.c
> index 15d96a0..e54ab12 100644
> --- a/drivers/platform/x86/dell-laptop.c
> +++ b/drivers/platform/x86/dell-laptop.c
> @@ -29,6 +29,7 @@
>  #define WLAN_SWITCH_MASK 0
>  #define BT_SWITCH_MASK 1
>  #define WWAN_SWITCH_MASK 2
> +#define HW_SWITCH_SUPPORT 3
>  #define HW_SWITCH_MASK 16
>
>  /* This structure will be modified by the firmware when we enter
> @@ -240,7 +241,7 @@ static int dell_rfkill_set(void *data, bool blocked)
>        int disable = blocked ? 1 : 0;
>        unsigned long radio = (unsigned long)data;
>
> -       if (!(hw_switch_status & BIT(radio-1)) || !(hw_switch_status & BIT(HW_SWITCH_MASK))) {
> +       if (!(hw_switch_status & BIT(radio-1)) || !(hw_switch_status & BIT(HW_SWITCH_MASK)) || !(hw_switch_status & BIT(HW_SWITCH_SUPPORT))) {

Coding style perspective, this is too long. You can either wrap it
or introduce a static inline function, e.g. hw_support_switch() to
clean up the conditions here.

>                memset(&buffer, 0, sizeof(struct calling_interface_buffer));
>                buffer.input[0] = (1 | (radio<<8) | (disable << 16));
>                dell_send_request(&buffer, 17, 11);
> @@ -258,6 +259,7 @@ static void dell_rfkill_query(struct rfkill *rfkill, void *data)
>        dell_send_request(&buffer, 17, 11);
>        status = buffer.output[1];
>
> +       hw_switch_status |= (status & BIT(0)) << BIT(HW_SWITCH_SUPPORT);
>        hw_switch_status |= (status & BIT(HW_SWITCH_MASK)) ^ BIT(HW_SWITCH_MASK);
>

Patch looks good to me, and we should get this upstreamed as well.
Stefan Bader - June 9, 2010, 9:39 a.m.
The patch is small (Eric's comment about the line length should be taken care
of) but I wonder a bit about other systems. This adds setting a bit without
being obvious whether that get restricted to hw that requires it. What happens
on hw that does not require this special handling?
So I definitely want that to be coming back from upstream instead of SRU it
manually. Make  sure you submit it as a stable patch, then we will get it
automatically.

-Stefan

On 06/09/2010 09:44 AM, Keng-Yu Lin wrote:
> SRU Justification:
> 
> Impact:
> A type of Dell Inspiron Mini does not turn off bluetooth physically when
> pressing F2 (rfkill hotkey). 
> 
> Fix: 
> Current kernel code expects hardware to handle the hard-rfkill switching
> spontaneously and only notify rfkill subsystem with the status change.
> This patch makes kernel to explicitly fire a SMI to switch on/off
> rfkill devices if BIOS reports that the hardware switch is not supported.
> 
> This patch depends on the following sauce patch in lucid kernel so is not going upstream:
> 	UBUNTU: SAUCE: dell-laptop: Store the HW switch status internally rather than requerying every time
> 
> Testcase: 
> I tested the patch on a Dell Mini 10. It works smoothly.
> 
> --
> From b17359e833677297d4d5daf78e4d9dc460e51285 Mon Sep 17 00:00:00 2001
> From: Keng-Yu Lin <keng-yu.lin@canonical.com>
> Date: Thu, 3 Jun 2010 10:31:56 +0800
> Subject: [PATCH] UBUNTU: SAUCE: dell-laptop: fire SMI when toggling hardware killswitch
> 
> When BIOS reports hardware switch is not supported, it does not turn on/off all
> devices spontaneously. So it is neccessary to fire an SMI to switch the rfkill
> status explicitly when toggling the hardware killswitch.
> 
> BugLink: http://bugs.launchpad.net/bugs/590607
> 
> Signed-off-by: Keng-Yu Lin <keng-yu.lin@canonical.com>
> ---
>  drivers/platform/x86/dell-laptop.c |    4 +++-
>  1 files changed, 3 insertions(+), 1 deletions(-)
> 
> diff --git a/drivers/platform/x86/dell-laptop.c b/drivers/platform/x86/dell-laptop.c
> index 15d96a0..e54ab12 100644
> --- a/drivers/platform/x86/dell-laptop.c
> +++ b/drivers/platform/x86/dell-laptop.c
> @@ -29,6 +29,7 @@
>  #define WLAN_SWITCH_MASK 0
>  #define BT_SWITCH_MASK 1
>  #define WWAN_SWITCH_MASK 2
> +#define HW_SWITCH_SUPPORT 3
>  #define HW_SWITCH_MASK 16
>  
>  /* This structure will be modified by the firmware when we enter
> @@ -240,7 +241,7 @@ static int dell_rfkill_set(void *data, bool blocked)
>  	int disable = blocked ? 1 : 0;
>  	unsigned long radio = (unsigned long)data;
>  
> -	if (!(hw_switch_status & BIT(radio-1)) || !(hw_switch_status & BIT(HW_SWITCH_MASK))) {
> +	if (!(hw_switch_status & BIT(radio-1)) || !(hw_switch_status & BIT(HW_SWITCH_MASK)) || !(hw_switch_status & BIT(HW_SWITCH_SUPPORT))) {
>  		memset(&buffer, 0, sizeof(struct calling_interface_buffer));
>  		buffer.input[0] = (1 | (radio<<8) | (disable << 16));
>  		dell_send_request(&buffer, 17, 11);
> @@ -258,6 +259,7 @@ static void dell_rfkill_query(struct rfkill *rfkill, void *data)
>  	dell_send_request(&buffer, 17, 11);
>  	status = buffer.output[1];
>  
> +	hw_switch_status |= (status & BIT(0)) << BIT(HW_SWITCH_SUPPORT);
>  	hw_switch_status |= (status & BIT(HW_SWITCH_MASK)) ^ BIT(HW_SWITCH_MASK);
>  
>  	/* HW switch control not supported
Keng-Yu Lin - June 9, 2010, 10:05 a.m.
2010/6/9 Stefan Bader <stefan.bader@canonical.com>:
> The patch is small (Eric's comment about the line length should be taken care
> of) but I wonder a bit about other systems. This adds setting a bit without
> being obvious whether that get restricted to hw that requires it. What happens
> on hw that does not require this special handling?
> So I definitely want that to be coming back from upstream instead of SRU it
> manually. Make  sure you submit it as a stable patch, then we will get it
> automatically.
>
> -Stefan
>
> On 06/09/2010 09:44 AM, Keng-Yu Lin wrote:
>> SRU Justification:
>>
>> Impact:
>> A type of Dell Inspiron Mini does not turn off bluetooth physically when
>> pressing F2 (rfkill hotkey).
>>
>> Fix:
>> Current kernel code expects hardware to handle the hard-rfkill switching
>> spontaneously and only notify rfkill subsystem with the status change.
>> This patch makes kernel to explicitly fire a SMI to switch on/off
>> rfkill devices if BIOS reports that the hardware switch is not supported.
>>
>> This patch depends on the following sauce patch in lucid kernel so is not going upstream:
>>       UBUNTU: SAUCE: dell-laptop: Store the HW switch status internally rather than requerying every time
>>
>> Testcase:
>> I tested the patch on a Dell Mini 10. It works smoothly.
>>
>> --
>> From b17359e833677297d4d5daf78e4d9dc460e51285 Mon Sep 17 00:00:00 2001
>> From: Keng-Yu Lin <keng-yu.lin@canonical.com>
>> Date: Thu, 3 Jun 2010 10:31:56 +0800
>> Subject: [PATCH] UBUNTU: SAUCE: dell-laptop: fire SMI when toggling hardware killswitch
>>
>> When BIOS reports hardware switch is not supported, it does not turn on/off all
>> devices spontaneously. So it is neccessary to fire an SMI to switch the rfkill
>> status explicitly when toggling the hardware killswitch.
>>
>> BugLink: http://bugs.launchpad.net/bugs/590607
>>
>> Signed-off-by: Keng-Yu Lin <keng-yu.lin@canonical.com>
>> ---
>>  drivers/platform/x86/dell-laptop.c |    4 +++-
>>  1 files changed, 3 insertions(+), 1 deletions(-)
>>
>> diff --git a/drivers/platform/x86/dell-laptop.c b/drivers/platform/x86/dell-laptop.c
>> index 15d96a0..e54ab12 100644
>> --- a/drivers/platform/x86/dell-laptop.c
>> +++ b/drivers/platform/x86/dell-laptop.c
>> @@ -29,6 +29,7 @@
>>  #define WLAN_SWITCH_MASK 0
>>  #define BT_SWITCH_MASK 1
>>  #define WWAN_SWITCH_MASK 2
>> +#define HW_SWITCH_SUPPORT 3
>>  #define HW_SWITCH_MASK 16
>>
>>  /* This structure will be modified by the firmware when we enter
>> @@ -240,7 +241,7 @@ static int dell_rfkill_set(void *data, bool blocked)
>>       int disable = blocked ? 1 : 0;
>>       unsigned long radio = (unsigned long)data;
>>
>> -     if (!(hw_switch_status & BIT(radio-1)) || !(hw_switch_status & BIT(HW_SWITCH_MASK))) {
>> +     if (!(hw_switch_status & BIT(radio-1)) || !(hw_switch_status & BIT(HW_SWITCH_MASK)) || !(hw_switch_status & BIT(HW_SWITCH_SUPPORT))) {
>>               memset(&buffer, 0, sizeof(struct calling_interface_buffer));
>>               buffer.input[0] = (1 | (radio<<8) | (disable << 16));
>>               dell_send_request(&buffer, 17, 11);
>> @@ -258,6 +259,7 @@ static void dell_rfkill_query(struct rfkill *rfkill, void *data)
>>       dell_send_request(&buffer, 17, 11);
>>       status = buffer.output[1];
>>
>> +     hw_switch_status |= (status & BIT(0)) << BIT(HW_SWITCH_SUPPORT);
>>       hw_switch_status |= (status & BIT(HW_SWITCH_MASK)) ^ BIT(HW_SWITCH_MASK);
>>
>>       /* HW switch control not supported
>
>

Hi Stefan:
  This patch is restricted to a BIOS reporting that hardware switch is
not supported (BIT 0 off of status variable). If hardware does control
the rfkill, BIT 0 should be on, as I observed on Dell inspiron N3010
in hand. Then this patch changes no original behavior.
  There are several sauce patches for dell-laptop.c in lucid tree. The
code difference between lucid tree and stable tree makes it difficult
to fix in a simple patch.
  I will try to write a new patch for upstream (.35 kernel), but it
should be implemented in different ways.

Eric:
  Thanks for mentioning the line length. should be careful of that.

  Regards,
-kengyu
Stefan Bader - June 9, 2010, 1:08 p.m.
On 06/09/2010 12:05 PM, Keng-Yü Lin wrote:
> 2010/6/9 Stefan Bader <stefan.bader@canonical.com>:
>> The patch is small (Eric's comment about the line length should be taken care
>> of) but I wonder a bit about other systems. This adds setting a bit without
>> being obvious whether that get restricted to hw that requires it. What happens
>> on hw that does not require this special handling?
>> So I definitely want that to be coming back from upstream instead of SRU it
>> manually. Make  sure you submit it as a stable patch, then we will get it
>> automatically.
>>
>> -Stefan
>>
>> On 06/09/2010 09:44 AM, Keng-Yu Lin wrote:
>>> SRU Justification:
>>>
>>> Impact:
>>> A type of Dell Inspiron Mini does not turn off bluetooth physically when
>>> pressing F2 (rfkill hotkey).
>>>
>>> Fix:
>>> Current kernel code expects hardware to handle the hard-rfkill switching
>>> spontaneously and only notify rfkill subsystem with the status change.
>>> This patch makes kernel to explicitly fire a SMI to switch on/off
>>> rfkill devices if BIOS reports that the hardware switch is not supported.
>>>
>>> This patch depends on the following sauce patch in lucid kernel so is not going upstream:
>>>       UBUNTU: SAUCE: dell-laptop: Store the HW switch status internally rather than requerying every time
>>>
>>> Testcase:
>>> I tested the patch on a Dell Mini 10. It works smoothly.
>>>
>>> --
>>> From b17359e833677297d4d5daf78e4d9dc460e51285 Mon Sep 17 00:00:00 2001
>>> From: Keng-Yu Lin <keng-yu.lin@canonical.com>
>>> Date: Thu, 3 Jun 2010 10:31:56 +0800
>>> Subject: [PATCH] UBUNTU: SAUCE: dell-laptop: fire SMI when toggling hardware killswitch
>>>
>>> When BIOS reports hardware switch is not supported, it does not turn on/off all
>>> devices spontaneously. So it is neccessary to fire an SMI to switch the rfkill
>>> status explicitly when toggling the hardware killswitch.
>>>
>>> BugLink: http://bugs.launchpad.net/bugs/590607
>>>
>>> Signed-off-by: Keng-Yu Lin <keng-yu.lin@canonical.com>
>>> ---
>>>  drivers/platform/x86/dell-laptop.c |    4 +++-
>>>  1 files changed, 3 insertions(+), 1 deletions(-)
>>>
>>> diff --git a/drivers/platform/x86/dell-laptop.c b/drivers/platform/x86/dell-laptop.c
>>> index 15d96a0..e54ab12 100644
>>> --- a/drivers/platform/x86/dell-laptop.c
>>> +++ b/drivers/platform/x86/dell-laptop.c
>>> @@ -29,6 +29,7 @@
>>>  #define WLAN_SWITCH_MASK 0
>>>  #define BT_SWITCH_MASK 1
>>>  #define WWAN_SWITCH_MASK 2
>>> +#define HW_SWITCH_SUPPORT 3
>>>  #define HW_SWITCH_MASK 16
>>>
>>>  /* This structure will be modified by the firmware when we enter
>>> @@ -240,7 +241,7 @@ static int dell_rfkill_set(void *data, bool blocked)
>>>       int disable = blocked ? 1 : 0;
>>>       unsigned long radio = (unsigned long)data;
>>>
>>> -     if (!(hw_switch_status & BIT(radio-1)) || !(hw_switch_status & BIT(HW_SWITCH_MASK))) {
>>> +     if (!(hw_switch_status & BIT(radio-1)) || !(hw_switch_status & BIT(HW_SWITCH_MASK)) || !(hw_switch_status & BIT(HW_SWITCH_SUPPORT))) {
>>>               memset(&buffer, 0, sizeof(struct calling_interface_buffer));
>>>               buffer.input[0] = (1 | (radio<<8) | (disable << 16));
>>>               dell_send_request(&buffer, 17, 11);
>>> @@ -258,6 +259,7 @@ static void dell_rfkill_query(struct rfkill *rfkill, void *data)
>>>       dell_send_request(&buffer, 17, 11);
>>>       status = buffer.output[1];
>>>
>>> +     hw_switch_status |= (status & BIT(0)) << BIT(HW_SWITCH_SUPPORT);
>>>       hw_switch_status |= (status & BIT(HW_SWITCH_MASK)) ^ BIT(HW_SWITCH_MASK);
>>>
>>>       /* HW switch control not supported
>>
>>
> 
> Hi Stefan:
>   This patch is restricted to a BIOS reporting that hardware switch is
> not supported (BIT 0 off of status variable). If hardware does control
> the rfkill, BIT 0 should be on, as I observed on Dell inspiron N3010
> in hand. Then this patch changes no original behavior.

>   There are several sauce patches for dell-laptop.c in lucid tree. The
> code difference between lucid tree and stable tree makes it difficult
> to fix in a simple patch.

Ok, sorry I missed that note about the SAUCE patch in the initial request. But
it would bring up the question to me, why the other patch has not gone upstream.
Was it tried but rejected? If so, why?
Is the same patch not needed for Maverick? Is the other patch in there? This
sounds a bit like being simpler to forget things on the way forward.

-Stefan

Stefan
>   I will try to write a new patch for upstream (.35 kernel), but it
> should be implemented in different ways.
> 
> Eric:
>   Thanks for mentioning the line length. should be careful of that.
> 
>   Regards,
> -kengyu
Chase Douglas - June 9, 2010, 2:11 p.m.
On Wed, 2010-06-09 at 15:08 +0200, Stefan Bader wrote:
> On 06/09/2010 12:05 PM, Keng-Yü Lin wrote:
> >   There are several sauce patches for dell-laptop.c in lucid tree. The
> > code difference between lucid tree and stable tree makes it difficult
> > to fix in a simple patch.
> 
> Ok, sorry I missed that note about the SAUCE patch in the initial request. But
> it would bring up the question to me, why the other patch has not gone upstream.
> Was it tried but rejected? If so, why?
> Is the same patch not needed for Maverick? Is the other patch in there? This
> sounds a bit like being simpler to forget things on the way forward.

I think way back in the early lucid development some patches were
applied to our tree that did not come from upstream. Matthew Garrett,
the upstream maintainer, took the patches and reworked them some.
However, the damage is done now, so we can't converge the two without a
wholesale replacement of parts of the lucid driver.

That said, we need to be sure that anything we put into Lucid is also
pushed upstream in a form that is applicable to their sources. In fact,
it may make the most sense to push changes to this driver upstream
first, and then propose a reworked version for lucid once it is
accepted.

-- Chase
Keng-Yu Lin - June 10, 2010, 6:37 a.m.
2010/6/9 Chase Douglas <chase.douglas@canonical.com>:
> On Wed, 2010-06-09 at 15:08 +0200, Stefan Bader wrote:
>> On 06/09/2010 12:05 PM, Keng-Yü Lin wrote:
>> >   There are several sauce patches for dell-laptop.c in lucid tree. The
>> > code difference between lucid tree and stable tree makes it difficult
>> > to fix in a simple patch.
>>
>> Ok, sorry I missed that note about the SAUCE patch in the initial request. But
>> it would bring up the question to me, why the other patch has not gone upstream.
>> Was it tried but rejected? If so, why?
>> Is the same patch not needed for Maverick? Is the other patch in there? This
>> sounds a bit like being simpler to forget things on the way forward.
>
> I think way back in the early lucid development some patches were
> applied to our tree that did not come from upstream. Matthew Garrett,
> the upstream maintainer, took the patches and reworked them some.
> However, the damage is done now, so we can't converge the two without a
> wholesale replacement of parts of the lucid driver.
>
> That said, we need to be sure that anything we put into Lucid is also
> pushed upstream in a form that is applicable to their sources. In fact,
> it may make the most sense to push changes to this driver upstream
> first, and then propose a reworked version for lucid once it is
> accepted.
>
> -- Chase
>
>

dug back to the history found that several of these SAUCE patches
exist since karmic. much the same discussion two month ago while Chase
sent a patch on the same driver. Some explanation in that thread by
Mario Limonciello:

  "As I recall, during karmic we pulled a patch that didn't make it
upstream in the form we have it, and a bunch of those other patches
layered on top of it. I didn't have any type of notification that a
different form had finally landed until Matthew started pulling some
of the patches we had in too."

I tested maverick kernel (2.6.32-2.2) on the machine and this bug is
there. This sauce patch here does not fit in maverick or upstream. I
think I will work another patch for it without depending on the
previous sauce patch code.

agreed that it's a better process to fix upstream first and then gets
backported somehow. But I encountered this issue while working on some
enablement for lucid. This is why the patch for lucid comes first.


  Regards,
-kengyu

Patch

diff --git a/drivers/platform/x86/dell-laptop.c b/drivers/platform/x86/dell-laptop.c
index 15d96a0..e54ab12 100644
--- a/drivers/platform/x86/dell-laptop.c
+++ b/drivers/platform/x86/dell-laptop.c
@@ -29,6 +29,7 @@ 
 #define WLAN_SWITCH_MASK 0
 #define BT_SWITCH_MASK 1
 #define WWAN_SWITCH_MASK 2
+#define HW_SWITCH_SUPPORT 3
 #define HW_SWITCH_MASK 16
 
 /* This structure will be modified by the firmware when we enter
@@ -240,7 +241,7 @@  static int dell_rfkill_set(void *data, bool blocked)
 	int disable = blocked ? 1 : 0;
 	unsigned long radio = (unsigned long)data;
 
-	if (!(hw_switch_status & BIT(radio-1)) || !(hw_switch_status & BIT(HW_SWITCH_MASK))) {
+	if (!(hw_switch_status & BIT(radio-1)) || !(hw_switch_status & BIT(HW_SWITCH_MASK)) || !(hw_switch_status & BIT(HW_SWITCH_SUPPORT))) {
 		memset(&buffer, 0, sizeof(struct calling_interface_buffer));
 		buffer.input[0] = (1 | (radio<<8) | (disable << 16));
 		dell_send_request(&buffer, 17, 11);
@@ -258,6 +259,7 @@  static void dell_rfkill_query(struct rfkill *rfkill, void *data)
 	dell_send_request(&buffer, 17, 11);
 	status = buffer.output[1];
 
+	hw_switch_status |= (status & BIT(0)) << BIT(HW_SWITCH_SUPPORT);
 	hw_switch_status |= (status & BIT(HW_SWITCH_MASK)) ^ BIT(HW_SWITCH_MASK);
 
 	/* HW switch control not supported