[Intel-gfx] [PATCH 3/4] drm/i915: Support for higher DSI clk

Ville Syrjälä ville.syrjala at linux.intel.com
Tue May 12 09:49:26 PDT 2015


On Tue, May 12, 2015 at 05:20:40PM +0300, Jani Nikula wrote:
> From: Gaurav K Singh <gaurav.k.singh at intel.com>
> 
> For MIPI panels requiring higher DSI clk, values needs to be added
> in lfsr_converts table for getting the correct values of pll ctrl
> and dividor values which gets programmed in cck regs, otherwise DSI
> PLL does not get locked leading to no display on the MIPI panel.
> 
> Signed-off-by: Gaurav K Singh <gaurav.k.singh at intel.com>
> Signed-off-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
> Signed-off-by: Jani Nikula <jani.nikula at intel.com>
> ---
>  drivers/gpu/drm/i915/intel_dsi_pll.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_dsi_pll.c b/drivers/gpu/drm/i915/intel_dsi_pll.c
> index effb561e00a0..d1aefc7a0629 100644
> --- a/drivers/gpu/drm/i915/intel_dsi_pll.c
> +++ b/drivers/gpu/drm/i915/intel_dsi_pll.c
> @@ -67,8 +67,8 @@ struct dsi_mnp {
>  static const u32 lfsr_converts[] = {
>  	426, 469, 234, 373, 442, 221, 110, 311, 411,		/* 62 - 70 */
>  	461, 486, 243, 377, 188, 350, 175, 343, 427, 213,	/* 71 - 80 */
> -	106, 53, 282, 397, 354, 227, 113, 56, 284, 142,		/* 81 - 90 */
> -	71, 35							/* 91 - 92 */
> +	106, 53, 282, 397, 454, 227, 113, 56, 284, 142,		/* 81 - 90 */
> +	71, 35, 273, 136, 324, 418, 465, 488, 500, 506		/* 91 - 100 */

I've never seen any details about this lfsr in any docs. However this is
actually a subset of mdfld_m_converts[] in gma500, so based on that:

Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

>  };
>  
>  #ifdef DSI_CLK_FROM_RR
> -- 
> 2.1.4

-- 
Ville Syrjälä
Intel OTC


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