[Intel-gfx] [PATCH 1/2] drm/i915: constify find_section in VBT parsing

Jani Nikula jani.nikula at intel.com
Tue May 12 05:30:32 PDT 2015


On Tue, 12 May 2015, Ville Syrjälä <ville.syrjala at linux.intel.com> wrote:
> On Wed, Apr 15, 2015 at 03:18:28PM +0300, Jani Nikula wrote:
>> Make input and output of find_section const, and fix the fallout. We
>> shouldn't modify the VBT, so make the compiler help us here.
>> 
>> Signed-off-by: Jani Nikula <jani.nikula at intel.com>
>> ---
>>  drivers/gpu/drm/i915/intel_bios.c | 60 ++++++++++++++++++++-------------------
>>  1 file changed, 31 insertions(+), 29 deletions(-)
>> 
>> diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
>> index c08368c03dad..4e3f3f427178 100644
>> --- a/drivers/gpu/drm/i915/intel_bios.c
>> +++ b/drivers/gpu/drm/i915/intel_bios.c
>> @@ -36,10 +36,11 @@
>>  
>>  static int panel_type;
>>  
>> -static void *
>> -find_section(struct bdb_header *bdb, int section_id)
>> +static const void *
>> +find_section(const void *_bdb, int section_id)
>>  {
>> -	u8 *base = (u8 *)bdb;
>> +	const struct bdb_header *bdb = _bdb;
>> +	const u8 *base = _bdb;
>>  	int index = 0;
>>  	u16 total, current_size;
>>  	u8 current_id;
>> @@ -53,7 +54,7 @@ find_section(struct bdb_header *bdb, int section_id)
>>  		current_id = *(base + index);
>>  		index++;
>>  
>> -		current_size = *((u16 *)(base + index));
>> +		current_size = *((const u16 *)(base + index));
>>  		index += 2;
>>  
>>  		if (index + current_size > total)
>> @@ -69,7 +70,7 @@ find_section(struct bdb_header *bdb, int section_id)
>>  }
>>  
>>  static u16
>> -get_blocksize(void *p)
>> +get_blocksize(const void *p)
>>  {
>>  	u16 *block_ptr, block_size;
>>  
>> @@ -350,7 +351,7 @@ static void
>>  parse_sdvo_panel_data(struct drm_i915_private *dev_priv,
>>  		      struct bdb_header *bdb)
>>  {
>> -	struct lvds_dvo_timing *dvo_timing;
>> +	const struct lvds_dvo_timing *dvo_timing;
>>  	struct drm_display_mode *panel_fixed_mode;
>>  	int index;
>>  
>> @@ -361,7 +362,7 @@ parse_sdvo_panel_data(struct drm_i915_private *dev_priv,
>>  	}
>>  
>>  	if (index == -1) {
>> -		struct bdb_sdvo_lvds_options *sdvo_lvds_options;
>> +		const struct bdb_sdvo_lvds_options *sdvo_lvds_options;
>>  
>>  		sdvo_lvds_options = find_section(bdb, BDB_SDVO_LVDS_OPTIONS);
>>  		if (!sdvo_lvds_options)
>> @@ -405,7 +406,7 @@ parse_general_features(struct drm_i915_private *dev_priv,
>>  		       struct bdb_header *bdb)
>>  {
>>  	struct drm_device *dev = dev_priv->dev;
>> -	struct bdb_general_features *general;
>> +	const struct bdb_general_features *general;
>>  
>>  	general = find_section(bdb, BDB_GENERAL_FEATURES);
>>  	if (general) {
>> @@ -430,7 +431,7 @@ static void
>>  parse_general_definitions(struct drm_i915_private *dev_priv,
>>  			  struct bdb_header *bdb)
>>  {
>> -	struct bdb_general_definitions *general;
>> +	const struct bdb_general_definitions *general;
>>  
>>  	general = find_section(bdb, BDB_GENERAL_DEFINITIONS);
>>  	if (general) {
>> @@ -447,10 +448,10 @@ parse_general_definitions(struct drm_i915_private *dev_priv,
>>  	}
>>  }
>>  
>> -static union child_device_config *
>> -child_device_ptr(struct bdb_general_definitions *p_defs, int i)
>> +static const union child_device_config *
>> +child_device_ptr(const struct bdb_general_definitions *p_defs, int i)
>>  {
>> -	return (void *) &p_defs->devices[i * p_defs->child_dev_size];
>> +	return (const void *) &p_defs->devices[i * p_defs->child_dev_size];
>>  }
>>  
>>  static void
>> @@ -458,8 +459,8 @@ parse_sdvo_device_mapping(struct drm_i915_private *dev_priv,
>>  			  struct bdb_header *bdb)
>>  {
>>  	struct sdvo_device_mapping *p_mapping;
>> -	struct bdb_general_definitions *p_defs;
>> -	union child_device_config *p_child;
>> +	const struct bdb_general_definitions *p_defs;
>> +	const union child_device_config *p_child;
>>  	int i, child_device_num, count;
>>  	u16	block_size;
>>  
>> @@ -547,7 +548,7 @@ static void
>>  parse_driver_features(struct drm_i915_private *dev_priv,
>>  		       struct bdb_header *bdb)
>>  {
>> -	struct bdb_driver_features *driver;
>> +	const struct bdb_driver_features *driver;
>>  
>>  	driver = find_section(bdb, BDB_DRIVER_FEATURES);
>>  	if (!driver)
>> @@ -573,9 +574,9 @@ parse_driver_features(struct drm_i915_private *dev_priv,
>>  static void
>>  parse_edp(struct drm_i915_private *dev_priv, struct bdb_header *bdb)
>>  {
>> -	struct bdb_edp *edp;
>> -	struct edp_power_seq *edp_pps;
>> -	struct edp_link_params *edp_link_params;
>> +	const struct bdb_edp *edp;
>> +	const struct edp_power_seq *edp_pps;
>> +	const struct edp_link_params *edp_link_params;
>>  
>>  	edp = find_section(bdb, BDB_EDP);
>>  	if (!edp) {
>> @@ -680,8 +681,8 @@ parse_edp(struct drm_i915_private *dev_priv, struct bdb_header *bdb)
>>  static void
>>  parse_psr(struct drm_i915_private *dev_priv, struct bdb_header *bdb)
>>  {
>> -	struct bdb_psr *psr;
>> -	struct psr_table *psr_table;
>> +	const struct bdb_psr *psr;
>> +	const struct psr_table *psr_table;
>>  
>>  	psr = find_section(bdb, BDB_PSR);
>>  	if (!psr) {
>> @@ -791,11 +792,12 @@ static u8 *goto_next_sequence(u8 *data, int *size)
>>  static void
>>  parse_mipi(struct drm_i915_private *dev_priv, struct bdb_header *bdb)
>>  {
>> -	struct bdb_mipi_config *start;
>> -	struct bdb_mipi_sequence *sequence;
>> -	struct mipi_config *config;
>> -	struct mipi_pps_data *pps;
>> -	u8 *data, *seq_data;
>> +	const struct bdb_mipi_config *start;
>> +	const struct bdb_mipi_sequence *sequence;
>> +	const struct mipi_config *config;
>> +	const struct mipi_pps_data *pps;
>> +	u8 *data;
>
> It would seem this guy could be constified as well, with a bit of extra
> effort that is.

Perhaps, but that's not actually used to point that the VBT itself, but
rather a copy of it, so not as important. Maybe later. ;)

Jani.

>
> But the patch as is looks reasonable so:
> Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
>
>> +	const u8 *seq_data;
>>  	int i, panel_id, seq_size;
>>  	u16 block_size;
>>  
>> @@ -1063,8 +1065,9 @@ static void
>>  parse_device_mapping(struct drm_i915_private *dev_priv,
>>  		       struct bdb_header *bdb)
>>  {
>> -	struct bdb_general_definitions *p_defs;
>> -	union child_device_config *p_child, *child_dev_ptr;
>> +	const struct bdb_general_definitions *p_defs;
>> +	const union child_device_config *p_child;
>> +	union child_device_config *child_dev_ptr;
>>  	int i, child_device_num, count;
>>  	u16	block_size;
>>  
>> @@ -1121,8 +1124,7 @@ parse_device_mapping(struct drm_i915_private *dev_priv,
>>  
>>  		child_dev_ptr = dev_priv->vbt.child_dev + count;
>>  		count++;
>> -		memcpy((void *)child_dev_ptr, (void *)p_child,
>> -					sizeof(*p_child));
>> +		memcpy(child_dev_ptr, p_child, sizeof(*p_child));
>>  	}
>>  	return;
>>  }
>> -- 
>> 2.1.4
>> 
>> _______________________________________________
>> Intel-gfx mailing list
>> Intel-gfx at lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
>
> -- 
> Ville Syrjälä
> Intel OTC

-- 
Jani Nikula, Intel Open Source Technology Center


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