diff mbox series

[v1,01/13] drm/edid: add block count and data helper functions for drm_edid

Message ID a08352924ad49a32213d8979d43d480f3f7b4a11.1653381821.git.jani.nikula@intel.com (mailing list archive)
State New, archived
Headers show
Series drm/edid: expand on struct drm_edid usage | expand

Commit Message

Jani Nikula May 24, 2022, 10:39 a.m. UTC 
Add drm_edid based block count and data access helper functions that
take the EDID allocated size into account.

At the moment, the allocated size should always match the EDID size
indicated by the extension count, but this will change in the future.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
---
 drivers/gpu/drm/drm_edid.c | 42 +++++++++++++++++++++++++++++++-------
 1 file changed, 35 insertions(+), 7 deletions(-)

Comments

Andrzej Hajda May 24, 2022, 1:29 p.m. UTC | #1 
On 24.05.2022 12:39, Jani Nikula wrote:
> Add drm_edid based block count and data access helper functions that
> take the EDID allocated size into account.
> 
> At the moment, the allocated size should always match the EDID size
> indicated by the extension count, but this will change in the future.
> 
> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
> ---
>   drivers/gpu/drm/drm_edid.c | 42 +++++++++++++++++++++++++++++++-------
>   1 file changed, 35 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
> index 929fc0e46751..682d954a9e42 100644
> --- a/drivers/gpu/drm/drm_edid.c
> +++ b/drivers/gpu/drm/drm_edid.c
> @@ -1613,6 +1613,35 @@ static const void *edid_extension_block_data(const struct edid *edid, int index)
>   	return edid_block_data(edid, index + 1);
>   }
>   
> +static int drm_edid_block_count(const struct drm_edid *drm_edid)
> +{
> +	int num_blocks;
> +
> +	/* Starting point */
> +	num_blocks = edid_block_count(drm_edid->edid);
> +
> +	/* Limit by allocated size */
> +	num_blocks = min(num_blocks, (int)drm_edid->size / EDID_LENGTH);
> +
> +	return num_blocks;
> +}
> +
> +static int drm_edid_extension_block_count(const struct drm_edid *drm_edid)
> +{
> +	return drm_edid_block_count(drm_edid) - 1;
> +}
> +
> +static const void *drm_edid_block_data(const struct drm_edid *drm_edid, int index)
> +{
> +	return edid_block_data(drm_edid->edid, index);
> +}
> +
> +static const void *drm_edid_extension_block_data(const struct drm_edid *drm_edid,
> +						 int index)
> +{
> +	return edid_extension_block_data(drm_edid->edid, index);
> +}
> +
>   /*
>    * Initializer helper for legacy interfaces, where we have no choice but to
>    * trust edid size. Not for general purpose use.
> @@ -1665,8 +1694,8 @@ static const void *__drm_edid_iter_next(struct drm_edid_iter *iter)
>   	if (!iter->drm_edid)
>   		return NULL;
>   
> -	if (iter->index < edid_block_count(iter->drm_edid->edid))
> -		block = edid_block_data(iter->drm_edid->edid, iter->index++);
> +	if (iter->index < drm_edid_block_count(iter->drm_edid))
> +		block = drm_edid_block_data(iter->drm_edid, iter->index++);
>   
>   	return block;
>   }
> @@ -3574,22 +3603,21 @@ static int add_detailed_modes(struct drm_connector *connector,
>   const u8 *drm_find_edid_extension(const struct drm_edid *drm_edid,
>   				  int ext_id, int *ext_index)
>   {
> -	const struct edid *edid = drm_edid ? drm_edid->edid : NULL;

Do we still need this var?


>   	const u8 *edid_ext = NULL;
>   	int i;
>   
>   	/* No EDID or EDID extensions */
> -	if (!edid || !edid_extension_block_count(edid))
> +	if (!drm_edid || !drm_edid_extension_block_count(drm_edid))
>   		return NULL;
>   
>   	/* Find CEA extension */
> -	for (i = *ext_index; i < edid_extension_block_count(edid); i++) {
> -		edid_ext = edid_extension_block_data(edid, i);
> +	for (i = *ext_index; i < drm_edid_extension_block_count(drm_edid); i++) {
> +		edid_ext = drm_edid_extension_block_data(drm_edid, i);
>   		if (edid_block_tag(edid_ext) == ext_id)
>   			break;
>   	}
>   
> -	if (i >= edid_extension_block_count(edid))
> +	if (i >= drm_edid_extension_block_count(drm_edid))
>   		return NULL;
>   
>   	*ext_index = i + 1;

It looks OK. Some suggestions to consider:
1. While at it, refactor little bit the code to return ext from 'for' 
loop and NULL later (to kill after-loop checks, and better code IMO).
2. Implement kind of iterator, for example 
drm_edid_extension_block_next(drm_edid, edid_ext), then use loop:
for (edid_ext = NULL; edid_ext = drm_edid_extension_block_next(drm_edid, 
edid_ext;)
	...

Up to you.
Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>

Regards
Andrzej
Jani Nikula May 24, 2022, 1:41 p.m. UTC | #2 
On Tue, 24 May 2022, Andrzej Hajda <andrzej.hajda@intel.com> wrote:
> On 24.05.2022 12:39, Jani Nikula wrote:
>> Add drm_edid based block count and data access helper functions that
>> take the EDID allocated size into account.
>> 
>> At the moment, the allocated size should always match the EDID size
>> indicated by the extension count, but this will change in the future.
>> 
>> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
>> ---
>>   drivers/gpu/drm/drm_edid.c | 42 +++++++++++++++++++++++++++++++-------
>>   1 file changed, 35 insertions(+), 7 deletions(-)
>> 
>> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
>> index 929fc0e46751..682d954a9e42 100644
>> --- a/drivers/gpu/drm/drm_edid.c
>> +++ b/drivers/gpu/drm/drm_edid.c
>> @@ -1613,6 +1613,35 @@ static const void *edid_extension_block_data(const struct edid *edid, int index)
>>   	return edid_block_data(edid, index + 1);
>>   }
>>   
>> +static int drm_edid_block_count(const struct drm_edid *drm_edid)
>> +{
>> +	int num_blocks;
>> +
>> +	/* Starting point */
>> +	num_blocks = edid_block_count(drm_edid->edid);
>> +
>> +	/* Limit by allocated size */
>> +	num_blocks = min(num_blocks, (int)drm_edid->size / EDID_LENGTH);
>> +
>> +	return num_blocks;
>> +}
>> +
>> +static int drm_edid_extension_block_count(const struct drm_edid *drm_edid)
>> +{
>> +	return drm_edid_block_count(drm_edid) - 1;
>> +}
>> +
>> +static const void *drm_edid_block_data(const struct drm_edid *drm_edid, int index)
>> +{
>> +	return edid_block_data(drm_edid->edid, index);
>> +}
>> +
>> +static const void *drm_edid_extension_block_data(const struct drm_edid *drm_edid,
>> +						 int index)
>> +{
>> +	return edid_extension_block_data(drm_edid->edid, index);
>> +}
>> +
>>   /*
>>    * Initializer helper for legacy interfaces, where we have no choice but to
>>    * trust edid size. Not for general purpose use.
>> @@ -1665,8 +1694,8 @@ static const void *__drm_edid_iter_next(struct drm_edid_iter *iter)
>>   	if (!iter->drm_edid)
>>   		return NULL;
>>   
>> -	if (iter->index < edid_block_count(iter->drm_edid->edid))
>> -		block = edid_block_data(iter->drm_edid->edid, iter->index++);
>> +	if (iter->index < drm_edid_block_count(iter->drm_edid))
>> +		block = drm_edid_block_data(iter->drm_edid, iter->index++);
>>   
>>   	return block;
>>   }
>> @@ -3574,22 +3603,21 @@ static int add_detailed_modes(struct drm_connector *connector,
>>   const u8 *drm_find_edid_extension(const struct drm_edid *drm_edid,
>>   				  int ext_id, int *ext_index)
>>   {
>> -	const struct edid *edid = drm_edid ? drm_edid->edid : NULL;
>
> Do we still need this var?

I am removing it...?

>
>
>>   	const u8 *edid_ext = NULL;
>>   	int i;
>>   
>>   	/* No EDID or EDID extensions */
>> -	if (!edid || !edid_extension_block_count(edid))
>> +	if (!drm_edid || !drm_edid_extension_block_count(drm_edid))
>>   		return NULL;
>>   
>>   	/* Find CEA extension */
>> -	for (i = *ext_index; i < edid_extension_block_count(edid); i++) {
>> -		edid_ext = edid_extension_block_data(edid, i);
>> +	for (i = *ext_index; i < drm_edid_extension_block_count(drm_edid); i++) {
>> +		edid_ext = drm_edid_extension_block_data(drm_edid, i);
>>   		if (edid_block_tag(edid_ext) == ext_id)
>>   			break;
>>   	}
>>   
>> -	if (i >= edid_extension_block_count(edid))
>> +	if (i >= drm_edid_extension_block_count(drm_edid))
>>   		return NULL;
>>   
>>   	*ext_index = i + 1;
>
> It looks OK. Some suggestions to consider:
> 1. While at it, refactor little bit the code to return ext from 'for' 
> loop and NULL later (to kill after-loop checks, and better code IMO).
> 2. Implement kind of iterator, for example 
> drm_edid_extension_block_next(drm_edid, edid_ext), then use loop:
> for (edid_ext = NULL; edid_ext = drm_edid_extension_block_next(drm_edid, 
> edid_ext;)
> 	...
>
> Up to you.
> Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>

There's already the struct drm_edid_iter stuff that this could be
converted to, but just haven't gotten around to it yet. I'll follow up
with that later. Thanks for the review.

BR,
Jani.

>
> Regards
> Andrzej
>
Ville Syrjälä June 2, 2022, 4:54 p.m. UTC | #3 
On Tue, May 24, 2022 at 01:39:23PM +0300, Jani Nikula wrote:
> Add drm_edid based block count and data access helper functions that
> take the EDID allocated size into account.
> 
> At the moment, the allocated size should always match the EDID size
> indicated by the extension count, but this will change in the future.
> 
> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
> ---
>  drivers/gpu/drm/drm_edid.c | 42 +++++++++++++++++++++++++++++++-------
>  1 file changed, 35 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
> index 929fc0e46751..682d954a9e42 100644
> --- a/drivers/gpu/drm/drm_edid.c
> +++ b/drivers/gpu/drm/drm_edid.c
> @@ -1613,6 +1613,35 @@ static const void *edid_extension_block_data(const struct edid *edid, int index)
>  	return edid_block_data(edid, index + 1);
>  }
>  
> +static int drm_edid_block_count(const struct drm_edid *drm_edid)
> +{
> +	int num_blocks;
> +
> +	/* Starting point */
> +	num_blocks = edid_block_count(drm_edid->edid);
> +
> +	/* Limit by allocated size */
> +	num_blocks = min(num_blocks, (int)drm_edid->size / EDID_LENGTH);

Hmm. Is there a particular reason we couldn't just always
return drm_edid->size/EDID_LENGTH here? That is, why would we not
set drm_edid->size to always reflect the actual size of the EDID?

> +
> +	return num_blocks;
> +}
> +
> +static int drm_edid_extension_block_count(const struct drm_edid *drm_edid)
> +{
> +	return drm_edid_block_count(drm_edid) - 1;
> +}
> +
> +static const void *drm_edid_block_data(const struct drm_edid *drm_edid, int index)
> +{
> +	return edid_block_data(drm_edid->edid, index);
> +}
> +
> +static const void *drm_edid_extension_block_data(const struct drm_edid *drm_edid,
> +						 int index)
> +{
> +	return edid_extension_block_data(drm_edid->edid, index);
> +}
> +
>  /*
>   * Initializer helper for legacy interfaces, where we have no choice but to
>   * trust edid size. Not for general purpose use.
> @@ -1665,8 +1694,8 @@ static const void *__drm_edid_iter_next(struct drm_edid_iter *iter)
>  	if (!iter->drm_edid)
>  		return NULL;
>  
> -	if (iter->index < edid_block_count(iter->drm_edid->edid))
> -		block = edid_block_data(iter->drm_edid->edid, iter->index++);
> +	if (iter->index < drm_edid_block_count(iter->drm_edid))
> +		block = drm_edid_block_data(iter->drm_edid, iter->index++);
>  
>  	return block;
>  }
> @@ -3574,22 +3603,21 @@ static int add_detailed_modes(struct drm_connector *connector,
>  const u8 *drm_find_edid_extension(const struct drm_edid *drm_edid,
>  				  int ext_id, int *ext_index)
>  {
> -	const struct edid *edid = drm_edid ? drm_edid->edid : NULL;
>  	const u8 *edid_ext = NULL;
>  	int i;
>  
>  	/* No EDID or EDID extensions */
> -	if (!edid || !edid_extension_block_count(edid))
> +	if (!drm_edid || !drm_edid_extension_block_count(drm_edid))
>  		return NULL;
>  
>  	/* Find CEA extension */
> -	for (i = *ext_index; i < edid_extension_block_count(edid); i++) {
> -		edid_ext = edid_extension_block_data(edid, i);
> +	for (i = *ext_index; i < drm_edid_extension_block_count(drm_edid); i++) {
> +		edid_ext = drm_edid_extension_block_data(drm_edid, i);
>  		if (edid_block_tag(edid_ext) == ext_id)
>  			break;
>  	}
>  
> -	if (i >= edid_extension_block_count(edid))
> +	if (i >= drm_edid_extension_block_count(drm_edid))
>  		return NULL;
>  
>  	*ext_index = i + 1;
> -- 
> 2.30.2
Jani Nikula June 2, 2022, 5:08 p.m. UTC | #4 
On Thu, 02 Jun 2022, Ville Syrjälä <ville.syrjala@linux.intel.com> wrote:
> On Tue, May 24, 2022 at 01:39:23PM +0300, Jani Nikula wrote:
>> Add drm_edid based block count and data access helper functions that
>> take the EDID allocated size into account.
>> 
>> At the moment, the allocated size should always match the EDID size
>> indicated by the extension count, but this will change in the future.
>> 
>> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
>> ---
>>  drivers/gpu/drm/drm_edid.c | 42 +++++++++++++++++++++++++++++++-------
>>  1 file changed, 35 insertions(+), 7 deletions(-)
>> 
>> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
>> index 929fc0e46751..682d954a9e42 100644
>> --- a/drivers/gpu/drm/drm_edid.c
>> +++ b/drivers/gpu/drm/drm_edid.c
>> @@ -1613,6 +1613,35 @@ static const void *edid_extension_block_data(const struct edid *edid, int index)
>>  	return edid_block_data(edid, index + 1);
>>  }
>>  
>> +static int drm_edid_block_count(const struct drm_edid *drm_edid)
>> +{
>> +	int num_blocks;
>> +
>> +	/* Starting point */
>> +	num_blocks = edid_block_count(drm_edid->edid);
>> +
>> +	/* Limit by allocated size */
>> +	num_blocks = min(num_blocks, (int)drm_edid->size / EDID_LENGTH);
>
> Hmm. Is there a particular reason we couldn't just always
> return drm_edid->size/EDID_LENGTH here? That is, why would we not
> set drm_edid->size to always reflect the actual size of the EDID?

Basically playing it safe for obscure cases and the future. For example
EDIDs originating from firmware, debugfs or i915 opregion could have a
bigger size than indicated by the extension count, if we want to go to a
direction where it's really just a blob with size.

BR,
Jani.

>
>> +
>> +	return num_blocks;
>> +}
>> +
>> +static int drm_edid_extension_block_count(const struct drm_edid *drm_edid)
>> +{
>> +	return drm_edid_block_count(drm_edid) - 1;
>> +}
>> +
>> +static const void *drm_edid_block_data(const struct drm_edid *drm_edid, int index)
>> +{
>> +	return edid_block_data(drm_edid->edid, index);
>> +}
>> +
>> +static const void *drm_edid_extension_block_data(const struct drm_edid *drm_edid,
>> +						 int index)
>> +{
>> +	return edid_extension_block_data(drm_edid->edid, index);
>> +}
>> +
>>  /*
>>   * Initializer helper for legacy interfaces, where we have no choice but to
>>   * trust edid size. Not for general purpose use.
>> @@ -1665,8 +1694,8 @@ static const void *__drm_edid_iter_next(struct drm_edid_iter *iter)
>>  	if (!iter->drm_edid)
>>  		return NULL;
>>  
>> -	if (iter->index < edid_block_count(iter->drm_edid->edid))
>> -		block = edid_block_data(iter->drm_edid->edid, iter->index++);
>> +	if (iter->index < drm_edid_block_count(iter->drm_edid))
>> +		block = drm_edid_block_data(iter->drm_edid, iter->index++);
>>  
>>  	return block;
>>  }
>> @@ -3574,22 +3603,21 @@ static int add_detailed_modes(struct drm_connector *connector,
>>  const u8 *drm_find_edid_extension(const struct drm_edid *drm_edid,
>>  				  int ext_id, int *ext_index)
>>  {
>> -	const struct edid *edid = drm_edid ? drm_edid->edid : NULL;
>>  	const u8 *edid_ext = NULL;
>>  	int i;
>>  
>>  	/* No EDID or EDID extensions */
>> -	if (!edid || !edid_extension_block_count(edid))
>> +	if (!drm_edid || !drm_edid_extension_block_count(drm_edid))
>>  		return NULL;
>>  
>>  	/* Find CEA extension */
>> -	for (i = *ext_index; i < edid_extension_block_count(edid); i++) {
>> -		edid_ext = edid_extension_block_data(edid, i);
>> +	for (i = *ext_index; i < drm_edid_extension_block_count(drm_edid); i++) {
>> +		edid_ext = drm_edid_extension_block_data(drm_edid, i);
>>  		if (edid_block_tag(edid_ext) == ext_id)
>>  			break;
>>  	}
>>  
>> -	if (i >= edid_extension_block_count(edid))
>> +	if (i >= drm_edid_extension_block_count(drm_edid))
>>  		return NULL;
>>  
>>  	*ext_index = i + 1;
>> -- 
>> 2.30.2
diff mbox series

Patch

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 929fc0e46751..682d954a9e42 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -1613,6 +1613,35 @@  static const void *edid_extension_block_data(const struct edid *edid, int index)
 	return edid_block_data(edid, index + 1);
 }
 
+static int drm_edid_block_count(const struct drm_edid *drm_edid)
+{
+	int num_blocks;
+
+	/* Starting point */
+	num_blocks = edid_block_count(drm_edid->edid);
+
+	/* Limit by allocated size */
+	num_blocks = min(num_blocks, (int)drm_edid->size / EDID_LENGTH);
+
+	return num_blocks;
+}
+
+static int drm_edid_extension_block_count(const struct drm_edid *drm_edid)
+{
+	return drm_edid_block_count(drm_edid) - 1;
+}
+
+static const void *drm_edid_block_data(const struct drm_edid *drm_edid, int index)
+{
+	return edid_block_data(drm_edid->edid, index);
+}
+
+static const void *drm_edid_extension_block_data(const struct drm_edid *drm_edid,
+						 int index)
+{
+	return edid_extension_block_data(drm_edid->edid, index);
+}
+
 /*
  * Initializer helper for legacy interfaces, where we have no choice but to
  * trust edid size. Not for general purpose use.
@@ -1665,8 +1694,8 @@  static const void *__drm_edid_iter_next(struct drm_edid_iter *iter)
 	if (!iter->drm_edid)
 		return NULL;
 
-	if (iter->index < edid_block_count(iter->drm_edid->edid))
-		block = edid_block_data(iter->drm_edid->edid, iter->index++);
+	if (iter->index < drm_edid_block_count(iter->drm_edid))
+		block = drm_edid_block_data(iter->drm_edid, iter->index++);
 
 	return block;
 }
@@ -3574,22 +3603,21 @@  static int add_detailed_modes(struct drm_connector *connector,
 const u8 *drm_find_edid_extension(const struct drm_edid *drm_edid,
 				  int ext_id, int *ext_index)
 {
-	const struct edid *edid = drm_edid ? drm_edid->edid : NULL;
 	const u8 *edid_ext = NULL;
 	int i;
 
 	/* No EDID or EDID extensions */
-	if (!edid || !edid_extension_block_count(edid))
+	if (!drm_edid || !drm_edid_extension_block_count(drm_edid))
 		return NULL;
 
 	/* Find CEA extension */
-	for (i = *ext_index; i < edid_extension_block_count(edid); i++) {
-		edid_ext = edid_extension_block_data(edid, i);
+	for (i = *ext_index; i < drm_edid_extension_block_count(drm_edid); i++) {
+		edid_ext = drm_edid_extension_block_data(drm_edid, i);
 		if (edid_block_tag(edid_ext) == ext_id)
 			break;
 	}
 
-	if (i >= edid_extension_block_count(edid))
+	if (i >= drm_edid_extension_block_count(drm_edid))
 		return NULL;
 
 	*ext_index = i + 1;