Re: [PATCH v3 5/7] drm/bridge: ti-sn65dsi86: Poll for DP PLL Lock

[spanda@codeaurora.org]

On 2018-08-14 03:00, Sean Paul wrote:
> From: Sean Paul <seanpaul@chromium.org>
> 
> Instead of just waiting and hoping, actually poll for the pll lock to 
> be
> acquired. As a bonus, this should be significantly faster than the
> sleep.
> 
> Changes in v3:
> - Added to the set
> 
> Cc: Sandeep Panda <spanda@codeaurora.org>
> Signed-off-by: Sean Paul <seanpaul@chromium.org>
> ---
>  drivers/gpu/drm/bridge/ti-sn65dsi86.c | 10 +++++++++-
>  1 file changed, 9 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c
> b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
> index d2119ab546147..f02bdedae1e5e 100644
> --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c
> +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
> @@ -456,6 +456,7 @@ static void ti_sn_bridge_enable(struct drm_bridge 
> *bridge)
>  {
>  	struct ti_sn_bridge *pdata = bridge_to_ti_sn_bridge(bridge);
>  	unsigned int val;
> +	int ret;
> 
>  	/* DSI_A lane config */
>  	val = CHA_DSI_LANES(4 - pdata->dsi->lanes);
> @@ -472,7 +473,14 @@ static void ti_sn_bridge_enable(struct drm_bridge 
> *bridge)
> 
>  	/* enable DP PLL */
>  	regmap_write(pdata->regmap, SN_PLL_ENABLE_REG, 1);
> -	usleep_range(10000, 10500); /* 10ms delay recommended by spec */
> +
> +	ret = regmap_read_poll_timeout(pdata->regmap, SN_DPPLL_SRC_REG, val,
> +				       val & DPPLL_SRC_DP_PLL_LOCK, 1000,
> +				       50 * 1000);
> +	if (ret) {
> +		DRM_ERROR("DP_PLL_LOCK polling failed (%d)\n", ret);
> +		return;
> +	}
> 
>  	/**
>  	 * The SN65DSI86 only supports ASSR Display Authentication method and
Reviewed-by: Sandeep Panda <spanda@codeaurora.org>
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