[Intel-gfx] [PATCH] drm/i915/bios: add helper for reading SPI

[Rodrigo Vivi]

On Fri, May 12, 2023 at 02:14:46PM +0300, Jani Nikula wrote:
> Add helper for reading SPI to not duplicate the write&read combo
> everywhere.
> 
> Signed-off-by: Jani Nikula <jani.nikula at intel.com>

BAT failure is likely a false positive on crcs... this patch
looks correct to me without any functional change.

Reviewed-by: Rodrigo Vivi <rodrigo.vivi at intel.com>


> ---
>  drivers/gpu/drm/i915/display/intel_bios.c | 23 ++++++++++++-----------
>  1 file changed, 12 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_bios.c b/drivers/gpu/drm/i915/display/intel_bios.c
> index 64eb11a45265..34a397adbd6b 100644
> --- a/drivers/gpu/drm/i915/display/intel_bios.c
> +++ b/drivers/gpu/drm/i915/display/intel_bios.c
> @@ -3033,6 +3033,13 @@ bool intel_bios_is_valid_vbt(const void *buf, size_t size)
>  	return vbt;
>  }
>  
> +static u32 intel_spi_read(struct intel_uncore *uncore, u32 offset)
> +{
> +	intel_uncore_write(uncore, PRIMARY_SPI_ADDRESS, offset);
> +
> +	return intel_uncore_read(uncore, PRIMARY_SPI_TRIGGER);
> +}
> +
>  static struct vbt_header *spi_oprom_get_vbt(struct drm_i915_private *i915)
>  {
>  	u32 count, data, found, store = 0;
> @@ -3049,9 +3056,7 @@ static struct vbt_header *spi_oprom_get_vbt(struct drm_i915_private *i915)
>  	oprom_offset &= OROM_OFFSET_MASK;
>  
>  	for (count = 0; count < oprom_size; count += 4) {
> -		intel_uncore_write(&i915->uncore, PRIMARY_SPI_ADDRESS, oprom_offset + count);
> -		data = intel_uncore_read(&i915->uncore, PRIMARY_SPI_TRIGGER);
> -
> +		data = intel_spi_read(&i915->uncore, oprom_offset + count);
>  		if (data == *((const u32 *)"$VBT")) {
>  			found = oprom_offset + count;
>  			break;
> @@ -3062,20 +3067,16 @@ static struct vbt_header *spi_oprom_get_vbt(struct drm_i915_private *i915)
>  		goto err_not_found;
>  
>  	/* Get VBT size and allocate space for the VBT */
> -	intel_uncore_write(&i915->uncore, PRIMARY_SPI_ADDRESS, found +
> -		   offsetof(struct vbt_header, vbt_size));
> -	vbt_size = intel_uncore_read(&i915->uncore, PRIMARY_SPI_TRIGGER);
> +	vbt_size = intel_spi_read(&i915->uncore,
> +				  found + offsetof(struct vbt_header, vbt_size));
>  	vbt_size &= 0xffff;
>  
>  	vbt = kzalloc(round_up(vbt_size, 4), GFP_KERNEL);
>  	if (!vbt)
>  		goto err_not_found;
>  
> -	for (count = 0; count < vbt_size; count += 4) {
> -		intel_uncore_write(&i915->uncore, PRIMARY_SPI_ADDRESS, found + count);
> -		data = intel_uncore_read(&i915->uncore, PRIMARY_SPI_TRIGGER);
> -		*(vbt + store++) = data;
> -	}
> +	for (count = 0; count < vbt_size; count += 4)
> +		*(vbt + store++) = intel_spi_read(&i915->uncore, found + count);
>  
>  	if (!intel_bios_is_valid_vbt(vbt, vbt_size))
>  		goto err_free_vbt;
> -- 
> 2.39.2
>