Re: [DPU PATCH v3 2/5] drm: add constant N value in helper file

[Jani Nikula <jani.nikula@linux.intel.com>]

On Mon, 02 Dec 2019, Chandan Uddaraju <chandanu@codeaurora.org> wrote:
> The constant N value (0x8000) is used by multiple DP
> drivers. Define this value in header file and use this
> in the existing i915 display driver.
>
> Signed-off-by: Chandan Uddaraju <chandanu@codeaurora.org>

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

and ack for merging via drm-misc or whichever tree you find suitable.


> ---
>  drivers/gpu/drm/i915/display/intel_display.c | 2 +-
>  include/drm/drm_dp_helper.h                  | 1 +
>  2 files changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index ce05e80..1a4ccfd 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -7496,7 +7496,7 @@ static void compute_m_n(unsigned int m, unsigned int n,
>  	 * which the devices expect also in synchronous clock mode.
>  	 */
>  	if (constant_n)
> -		*ret_n = 0x8000;
> +		*ret_n = DP_LINK_CONSTANT_N_VALUE;
>  	else
>  		*ret_n = min_t(unsigned int, roundup_pow_of_two(n), DATA_LINK_N_MAX);
>  
> diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
> index 8364502..69b8251 100644
> --- a/include/drm/drm_dp_helper.h
> +++ b/include/drm/drm_dp_helper.h
> @@ -1357,6 +1357,7 @@ int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux,
>   * DisplayPort link
>   */
>  #define DP_LINK_CAP_ENHANCED_FRAMING (1 << 0)
> +#define DP_LINK_CONSTANT_N_VALUE 0x8000
>  
>  struct drm_dp_link {
>  	unsigned char revision;

-- 
Jani Nikula, Intel Open Source Graphics Center