Re: [PATCHv3 03/30] drm/omap: remove divider constraint from hsdiv

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Tomi,

Thank you for the patch.

On Tuesday 28 Mar 2017 16:07:49 Tomi Valkeinen wrote:
> The driver only uses even dividers for hsdiv when pclk >= 100MHz, as odd
> dividers can create uneven duty cycle. However, while this holds true
> for some dividers like DISPC's LCK and PCK dividers, it is not actually
> true for hsdiv.
> 
> hsdiv always produces even duty cycle, so the constraint can be removed.
> 
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> ---
>  drivers/gpu/drm/omapdrm/dss/dpi.c | 8 --------
>  1 file changed, 8 deletions(-)
> 
> diff --git a/drivers/gpu/drm/omapdrm/dss/dpi.c
> b/drivers/gpu/drm/omapdrm/dss/dpi.c index e75162d26ac0..e0b0c5c24c55 100644
> --- a/drivers/gpu/drm/omapdrm/dss/dpi.c
> +++ b/drivers/gpu/drm/omapdrm/dss/dpi.c
> @@ -170,14 +170,6 @@ static bool dpi_calc_hsdiv_cb(int m_dispc, unsigned
> long dispc, {
>  	struct dpi_clk_calc_ctx *ctx = data;
> 
> -	/*
> -	 * Odd dividers give us uneven duty cycle, causing problem when level
> -	 * shifted. So skip all odd dividers when the pixel clock is on the
> -	 * higher side.
> -	 */
> -	if (m_dispc > 1 && m_dispc % 2 != 0 && ctx->pck_min >= 100000000)
> -		return false;
> -
>  	ctx->pll_cinfo.mX[ctx->clkout_idx] = m_dispc;
>  	ctx->pll_cinfo.clkout[ctx->clkout_idx] = dispc;

-- 
Regards,

Laurent Pinchart

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