[PATCH 1/1] drm/display: Fix building with GCC 15

[PATCH 1/1] drm/display: Fix building with GCC 15

[Brahmajit Das]

GCC 15 enables -Werror=unterminated-string-initialization by default.
This results in the following build error

drivers/gpu/drm/display/drm_dp_dual_mode_helper.c: In function ‘is_hdmi_adaptor’:
drivers/gpu/drm/display/drm_dp_dual_mode_helper.c:164:17: error: initializer-string for array of
 ‘char’ is too long [-Werror=unterminated-string-initialization]
  164 |                 "DP-HDMI ADAPTOR\x04";
      |                 ^~~~~~~~~~~~~~~~~~~~~

After discussion with Ville, the fix was to increase the size of
dp_dual_mode_hdmi_id array by one, so that it can accommodate the new
line character. This should let us build the kernel with GCC 15.

Signed-off-by: Brahmajit Das <brahmajit.xyz@gmail.com>
---
 drivers/gpu/drm/display/drm_dp_dual_mode_helper.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c b/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c
index 14a2a8473682..295375868db6 100644
--- a/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c
+++ b/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c
@@ -160,11 +160,12 @@ EXPORT_SYMBOL(drm_dp_dual_mode_write);
 
 static bool is_hdmi_adaptor(const char hdmi_id[DP_DUAL_MODE_HDMI_ID_LEN])
 {
-	static const char dp_dual_mode_hdmi_id[DP_DUAL_MODE_HDMI_ID_LEN] =
+	//+1 to avaoid spurious -Werror=unterminated-string-initialization warning
+	static const char dp_dual_mode_hdmi_id[DP_DUAL_MODE_HDMI_ID_LEN + 1] =
 		"DP-HDMI ADAPTOR\x04";
 
 	return memcmp(hdmi_id, dp_dual_mode_hdmi_id,
-		      sizeof(dp_dual_mode_hdmi_id)) == 0;
+		      DP_DUAL_MODE_HDMI_ID_LEN) == 0;
 }
 
 static bool is_type1_adaptor(uint8_t adaptor_id)
-- 
2.46.2

Re: [PATCH 1/1] drm/display: Fix building with GCC 15

[Jani Nikula]

On Tue, 01 Oct 2024, Brahmajit Das <brahmajit.xyz@gmail.com> wrote:
> GCC 15 enables -Werror=unterminated-string-initialization by default.
> This results in the following build error
>
> drivers/gpu/drm/display/drm_dp_dual_mode_helper.c: In function ‘is_hdmi_adaptor’:
> drivers/gpu/drm/display/drm_dp_dual_mode_helper.c:164:17: error: initializer-string for array of
>  ‘char’ is too long [-Werror=unterminated-string-initialization]
>   164 |                 "DP-HDMI ADAPTOR\x04";
>       |                 ^~~~~~~~~~~~~~~~~~~~~
>
> After discussion with Ville, the fix was to increase the size of
> dp_dual_mode_hdmi_id array by one, so that it can accommodate the new
> line character. This should let us build the kernel with GCC 15.

Should be terminating NUL, not new line.

>
> Signed-off-by: Brahmajit Das <brahmajit.xyz@gmail.com>
> ---
>  drivers/gpu/drm/display/drm_dp_dual_mode_helper.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c b/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c
> index 14a2a8473682..295375868db6 100644
> --- a/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c
> +++ b/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c
> @@ -160,11 +160,12 @@ EXPORT_SYMBOL(drm_dp_dual_mode_write);
>  
>  static bool is_hdmi_adaptor(const char hdmi_id[DP_DUAL_MODE_HDMI_ID_LEN])
>  {
> -	static const char dp_dual_mode_hdmi_id[DP_DUAL_MODE_HDMI_ID_LEN] =
> +	//+1 to avaoid spurious -Werror=unterminated-string-initialization warning

If we added comments for every little thing like this, there'd be more
comments than code. ;)

> +	static const char dp_dual_mode_hdmi_id[DP_DUAL_MODE_HDMI_ID_LEN + 1] =
>  		"DP-HDMI ADAPTOR\x04";
>  
>  	return memcmp(hdmi_id, dp_dual_mode_hdmi_id,
> -		      sizeof(dp_dual_mode_hdmi_id)) == 0;
> +		      DP_DUAL_MODE_HDMI_ID_LEN) == 0;
>  }
>  
>  static bool is_type1_adaptor(uint8_t adaptor_id)

-- 
Jani Nikula, Intel

[PATCH v2] drm/display: Fix building with GCC 15

[Brahmajit Das]

GCC 15 enables -Werror=unterminated-string-initialization by default.
This results in the following build error

drivers/gpu/drm/display/drm_dp_dual_mode_helper.c: In function ‘is_hdmi_adaptor’:
drivers/gpu/drm/display/drm_dp_dual_mode_helper.c:164:17: error: initializer-string for array of
 ‘char’ is too long [-Werror=unterminated-string-initialization]
  164 |                 "DP-HDMI ADAPTOR\x04";
      |                 ^~~~~~~~~~~~~~~~~~~~~

After discussion with Ville, the fix was to increase the size of
dp_dual_mode_hdmi_id array by one, so that it can accommodate the new
line character. This should let us build the kernel with GCC 15.

Signed-off-by: Brahmajit Das <brahmajit.xyz@gmail.com>
---
 drivers/gpu/drm/display/drm_dp_dual_mode_helper.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c b/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c
index 14a2a8473682..efb3c3494579 100644
--- a/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c
+++ b/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c
@@ -160,11 +160,11 @@ EXPORT_SYMBOL(drm_dp_dual_mode_write);
 
 static bool is_hdmi_adaptor(const char hdmi_id[DP_DUAL_MODE_HDMI_ID_LEN])
 {
-	static const char dp_dual_mode_hdmi_id[DP_DUAL_MODE_HDMI_ID_LEN] =
-		"DP-HDMI ADAPTOR\x04";
+	static const char dp_dual_mode_hdmi_id[DP_DUAL_MODE_HDMI_ID_LEN + 1] =
+		"DP-HDMI ADAPTOR\x00";
 
 	return memcmp(hdmi_id, dp_dual_mode_hdmi_id,
-		      sizeof(dp_dual_mode_hdmi_id)) == 0;
+		      DP_DUAL_MODE_HDMI_ID_LEN) == 0;
 }
 
 static bool is_type1_adaptor(uint8_t adaptor_id)
-- 
2.46.2

[PATCH v3] drm/display: Fix building with GCC 15

[Brahmajit Das]

GCC 15 enables -Werror=unterminated-string-initialization by default.
This results in the following build error

drivers/gpu/drm/display/drm_dp_dual_mode_helper.c: In function ‘is_hdmi_adaptor’:
drivers/gpu/drm/display/drm_dp_dual_mode_helper.c:164:17: error: initializer-string for array of
 ‘char’ is too long [-Werror=unterminated-string-initialization]
  164 |                 "DP-HDMI ADAPTOR\x04";
      |                 ^~~~~~~~~~~~~~~~~~~~~

After discussion with Ville, the fix was to increase the size of
dp_dual_mode_hdmi_id array by one, so that it can accommodate the NULL
line character. This should let us build the kernel with GCC 15.

Signed-off-by: Brahmajit Das <brahmajit.xyz@gmail.com>
---
 drivers/gpu/drm/display/drm_dp_dual_mode_helper.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c b/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c
index 14a2a8473682..c491e3203bf1 100644
--- a/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c
+++ b/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c
@@ -160,11 +160,11 @@ EXPORT_SYMBOL(drm_dp_dual_mode_write);
 
 static bool is_hdmi_adaptor(const char hdmi_id[DP_DUAL_MODE_HDMI_ID_LEN])
 {
-	static const char dp_dual_mode_hdmi_id[DP_DUAL_MODE_HDMI_ID_LEN] =
+	static const char dp_dual_mode_hdmi_id[DP_DUAL_MODE_HDMI_ID_LEN + 1] =
 		"DP-HDMI ADAPTOR\x04";
 
 	return memcmp(hdmi_id, dp_dual_mode_hdmi_id,
-		      sizeof(dp_dual_mode_hdmi_id)) == 0;
+		      DP_DUAL_MODE_HDMI_ID_LEN) == 0;
 }
 
 static bool is_type1_adaptor(uint8_t adaptor_id)
-- 
2.46.2

[PATCH v3] drm/display: Fix building with GCC 15

[Brahmajit Das]

GCC 15 enables -Werror=unterminated-string-initialization by default.
This results in the following build error

drivers/gpu/drm/display/drm_dp_dual_mode_helper.c: In function ‘is_hdmi_adaptor’:
drivers/gpu/drm/display/drm_dp_dual_mode_helper.c:164:17: error: initializer-string for array of
 ‘char’ is too long [-Werror=unterminated-string-initialization]
  164 |                 "DP-HDMI ADAPTOR\x04";
      |                 ^~~~~~~~~~~~~~~~~~~~~

After discussion with Ville, the fix was to increase the size of
dp_dual_mode_hdmi_id array by one, so that it can accommodate the NULL
line character. This should let us build the kernel with GCC 15.

Signed-off-by: Brahmajit Das <brahmajit.xyz@gmail.com>
---
 drivers/gpu/drm/display/drm_dp_dual_mode_helper.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c b/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c
index 14a2a8473682..c491e3203bf1 100644
--- a/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c
+++ b/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c
@@ -160,11 +160,11 @@ EXPORT_SYMBOL(drm_dp_dual_mode_write);
 
 static bool is_hdmi_adaptor(const char hdmi_id[DP_DUAL_MODE_HDMI_ID_LEN])
 {
-	static const char dp_dual_mode_hdmi_id[DP_DUAL_MODE_HDMI_ID_LEN] =
+	static const char dp_dual_mode_hdmi_id[DP_DUAL_MODE_HDMI_ID_LEN + 1] =
 		"DP-HDMI ADAPTOR\x04";
 
 	return memcmp(hdmi_id, dp_dual_mode_hdmi_id,
-		      sizeof(dp_dual_mode_hdmi_id)) == 0;
+		      DP_DUAL_MODE_HDMI_ID_LEN) == 0;
 }
 
 static bool is_type1_adaptor(uint8_t adaptor_id)
-- 
2.46.2

Re: [PATCH v3] drm/display: Fix building with GCC 15

[Jani Nikula]

On Wed, 02 Oct 2024, Brahmajit Das <brahmajit.xyz@gmail.com> wrote:
> GCC 15 enables -Werror=unterminated-string-initialization by default.
> This results in the following build error
>
> drivers/gpu/drm/display/drm_dp_dual_mode_helper.c: In function ‘is_hdmi_adaptor’:
> drivers/gpu/drm/display/drm_dp_dual_mode_helper.c:164:17: error: initializer-string for array of
>  ‘char’ is too long [-Werror=unterminated-string-initialization]
>   164 |                 "DP-HDMI ADAPTOR\x04";
>       |                 ^~~~~~~~~~~~~~~~~~~~~
>
> After discussion with Ville, the fix was to increase the size of
> dp_dual_mode_hdmi_id array by one, so that it can accommodate the NULL
> line character. This should let us build the kernel with GCC 15.

Still s/NULL line/NUL/ but this can be fixed while applying, no need to
resend.

Reviewed-by: Jani Nikula <jani.nikula@intel.com>


>
> Signed-off-by: Brahmajit Das <brahmajit.xyz@gmail.com>
> ---
>  drivers/gpu/drm/display/drm_dp_dual_mode_helper.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c b/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c
> index 14a2a8473682..c491e3203bf1 100644
> --- a/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c
> +++ b/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c
> @@ -160,11 +160,11 @@ EXPORT_SYMBOL(drm_dp_dual_mode_write);
>  
>  static bool is_hdmi_adaptor(const char hdmi_id[DP_DUAL_MODE_HDMI_ID_LEN])
>  {
> -	static const char dp_dual_mode_hdmi_id[DP_DUAL_MODE_HDMI_ID_LEN] =
> +	static const char dp_dual_mode_hdmi_id[DP_DUAL_MODE_HDMI_ID_LEN + 1] =
>  		"DP-HDMI ADAPTOR\x04";
>  
>  	return memcmp(hdmi_id, dp_dual_mode_hdmi_id,
> -		      sizeof(dp_dual_mode_hdmi_id)) == 0;
> +		      DP_DUAL_MODE_HDMI_ID_LEN) == 0;
>  }
>  
>  static bool is_type1_adaptor(uint8_t adaptor_id)

-- 
Jani Nikula, Intel

Re: [PATCH 1/1] drm/display: Fix building with GCC 15

[Ville Syrjälä]

On Wed, Oct 02, 2024 at 11:26:10AM +0300, Jani Nikula wrote:
> On Tue, 01 Oct 2024, Brahmajit Das <brahmajit.xyz@gmail.com> wrote:
> > GCC 15 enables -Werror=unterminated-string-initialization by default.
> > This results in the following build error
> >
> > drivers/gpu/drm/display/drm_dp_dual_mode_helper.c: In function ‘is_hdmi_adaptor’:
> > drivers/gpu/drm/display/drm_dp_dual_mode_helper.c:164:17: error: initializer-string for array of
> >  ‘char’ is too long [-Werror=unterminated-string-initialization]
> >   164 |                 "DP-HDMI ADAPTOR\x04";
> >       |                 ^~~~~~~~~~~~~~~~~~~~~
> >
> > After discussion with Ville, the fix was to increase the size of
> > dp_dual_mode_hdmi_id array by one, so that it can accommodate the new
> > line character. This should let us build the kernel with GCC 15.
> 
> Should be terminating NUL, not new line.
> 
> >
> > Signed-off-by: Brahmajit Das <brahmajit.xyz@gmail.com>
> > ---
> >  drivers/gpu/drm/display/drm_dp_dual_mode_helper.c | 5 +++--
> >  1 file changed, 3 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c b/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c
> > index 14a2a8473682..295375868db6 100644
> > --- a/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c
> > +++ b/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c
> > @@ -160,11 +160,12 @@ EXPORT_SYMBOL(drm_dp_dual_mode_write);
> >  
> >  static bool is_hdmi_adaptor(const char hdmi_id[DP_DUAL_MODE_HDMI_ID_LEN])
> >  {
> > -	static const char dp_dual_mode_hdmi_id[DP_DUAL_MODE_HDMI_ID_LEN] =
> > +	//+1 to avaoid spurious -Werror=unterminated-string-initialization warning
> 
> If we added comments for every little thing like this, there'd be more
> comments than code. ;)

I asked for a comment, otherwise I suspect I''d end up undoing this
after forgetting why it's there. OTOH maybe I'll get the "broken"
gcc upgrade before I look at this code again, which would solve
that particular problem.

> 
> > +	static const char dp_dual_mode_hdmi_id[DP_DUAL_MODE_HDMI_ID_LEN + 1] =
> >  		"DP-HDMI ADAPTOR\x04";
> >  
> >  	return memcmp(hdmi_id, dp_dual_mode_hdmi_id,
> > -		      sizeof(dp_dual_mode_hdmi_id)) == 0;
> > +		      DP_DUAL_MODE_HDMI_ID_LEN) == 0;
> >  }
> >  
> >  static bool is_type1_adaptor(uint8_t adaptor_id)
> 
> -- 
> Jani Nikula, Intel

-- 
Ville Syrjälä
Intel

Re: [PATCH v3] drm/display: Fix building with GCC 15

[Jani Nikula]

On Wed, 02 Oct 2024, Jani Nikula <jani.nikula@linux.intel.com> wrote:
> On Wed, 02 Oct 2024, Brahmajit Das <brahmajit.xyz@gmail.com> wrote:
>> GCC 15 enables -Werror=unterminated-string-initialization by default.
>> This results in the following build error
>>
>> drivers/gpu/drm/display/drm_dp_dual_mode_helper.c: In function ‘is_hdmi_adaptor’:
>> drivers/gpu/drm/display/drm_dp_dual_mode_helper.c:164:17: error: initializer-string for array of
>>  ‘char’ is too long [-Werror=unterminated-string-initialization]
>>   164 |                 "DP-HDMI ADAPTOR\x04";
>>       |                 ^~~~~~~~~~~~~~~~~~~~~
>>
>> After discussion with Ville, the fix was to increase the size of
>> dp_dual_mode_hdmi_id array by one, so that it can accommodate the NULL
>> line character. This should let us build the kernel with GCC 15.
>
> Still s/NULL line/NUL/ but this can be fixed while applying, no need to
> resend.
>
> Reviewed-by: Jani Nikula <jani.nikula@intel.com>

Pushed to drm-misc-next, and forgot to update the commit message. Oh
well. My bad.

Thanks for the patch.

BR,
Jani.

>
>
>>
>> Signed-off-by: Brahmajit Das <brahmajit.xyz@gmail.com>
>> ---
>>  drivers/gpu/drm/display/drm_dp_dual_mode_helper.c | 4 ++--
>>  1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c b/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c
>> index 14a2a8473682..c491e3203bf1 100644
>> --- a/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c
>> +++ b/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c
>> @@ -160,11 +160,11 @@ EXPORT_SYMBOL(drm_dp_dual_mode_write);
>>  
>>  static bool is_hdmi_adaptor(const char hdmi_id[DP_DUAL_MODE_HDMI_ID_LEN])
>>  {
>> -	static const char dp_dual_mode_hdmi_id[DP_DUAL_MODE_HDMI_ID_LEN] =
>> +	static const char dp_dual_mode_hdmi_id[DP_DUAL_MODE_HDMI_ID_LEN + 1] =
>>  		"DP-HDMI ADAPTOR\x04";
>>  
>>  	return memcmp(hdmi_id, dp_dual_mode_hdmi_id,
>> -		      sizeof(dp_dual_mode_hdmi_id)) == 0;
>> +		      DP_DUAL_MODE_HDMI_ID_LEN) == 0;
>>  }
>>  
>>  static bool is_type1_adaptor(uint8_t adaptor_id)

-- 
Jani Nikula, Intel