[PATCH] drm/omap: fix crash if there's no video PLL

[Keerthy]

On Thursday 05 April 2018 12:25 PM, Tomi Valkeinen wrote:
> Commit 8a7eda7686675b73d74c22c0d5b83059f9d783f6 ("drm: omapdrm: dispc:
> Pass DISPC pointer to remaining dispc API functions") made dpi.c use
> ctx->pll even when there's no PLL, causing a crash at modeset on AM4
> EVM, and presumably all OMAP2/3 boards.
> 
> Fix this by having struct dpi_data pointer in the ctx instead, giving
> access to dispc without going through the pll.

Tested for display coming up on boot which was earlier broken on
am437x-gp-evm.

Tested-by: Keerthy <j-keerthy at ti.com>

> 
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen at ti.com>
> Reported-by: Keerthy <j-keerthy at ti.com>
> Cc: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> ---
>  drivers/gpu/drm/omapdrm/dss/dpi.c | 15 ++++++++-------
>  1 file changed, 8 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/gpu/drm/omapdrm/dss/dpi.c b/drivers/gpu/drm/omapdrm/dss/dpi.c
> index fb1c27f69e3a..3d662e6805eb 100644
> --- a/drivers/gpu/drm/omapdrm/dss/dpi.c
> +++ b/drivers/gpu/drm/omapdrm/dss/dpi.c
> @@ -142,7 +142,7 @@ static enum dss_clk_source dpi_get_clk_src(struct dpi_data *dpi)
>  }
>  
>  struct dpi_clk_calc_ctx {
> -	struct dss_pll *pll;
> +	struct dpi_data *dpi;
>  	unsigned int clkout_idx;
>  
>  	/* inputs */
> @@ -191,7 +191,7 @@ static bool dpi_calc_hsdiv_cb(int m_dispc, unsigned long dispc,
>  	ctx->pll_cinfo.mX[ctx->clkout_idx] = m_dispc;
>  	ctx->pll_cinfo.clkout[ctx->clkout_idx] = dispc;
>  
> -	return dispc_div_calc(ctx->pll->dss->dispc, dispc,
> +	return dispc_div_calc(ctx->dpi->dss->dispc, dispc,
>  			      ctx->pck_min, ctx->pck_max,
>  			      dpi_calc_dispc_cb, ctx);
>  }
> @@ -208,8 +208,8 @@ static bool dpi_calc_pll_cb(int n, int m, unsigned long fint,
>  	ctx->pll_cinfo.fint = fint;
>  	ctx->pll_cinfo.clkdco = clkdco;
>  
> -	return dss_pll_hsdiv_calc_a(ctx->pll, clkdco,
> -		ctx->pck_min, dss_get_max_fck_rate(ctx->pll->dss),
> +	return dss_pll_hsdiv_calc_a(ctx->dpi->pll, clkdco,
> +		ctx->pck_min, dss_get_max_fck_rate(ctx->dpi->dss),
>  		dpi_calc_hsdiv_cb, ctx);
>  }
>  
> @@ -219,7 +219,7 @@ static bool dpi_calc_dss_cb(unsigned long fck, void *data)
>  
>  	ctx->fck = fck;
>  
> -	return dispc_div_calc(ctx->pll->dss->dispc, fck,
> +	return dispc_div_calc(ctx->dpi->dss->dispc, fck,
>  			      ctx->pck_min, ctx->pck_max,
>  			      dpi_calc_dispc_cb, ctx);
>  }
> @@ -230,7 +230,7 @@ static bool dpi_pll_clk_calc(struct dpi_data *dpi, unsigned long pck,
>  	unsigned long clkin;
>  
>  	memset(ctx, 0, sizeof(*ctx));
> -	ctx->pll = dpi->pll;
> +	ctx->dpi = dpi;
>  	ctx->clkout_idx = dss_pll_get_clkout_idx_for_src(dpi->clk_src);
>  
>  	clkin = clk_get_rate(dpi->pll->clkin);
> @@ -244,7 +244,7 @@ static bool dpi_pll_clk_calc(struct dpi_data *dpi, unsigned long pck,
>  		pll_min = 0;
>  		pll_max = 0;
>  
> -		return dss_pll_calc_a(ctx->pll, clkin,
> +		return dss_pll_calc_a(ctx->dpi->pll, clkin,
>  				pll_min, pll_max,
>  				dpi_calc_pll_cb, ctx);
>  	} else { /* DSS_PLL_TYPE_B */
> @@ -275,6 +275,7 @@ static bool dpi_dss_clk_calc(struct dpi_data *dpi, unsigned long pck,
>  		bool ok;
>  
>  		memset(ctx, 0, sizeof(*ctx));
> +		ctx->dpi = dpi;
>  		if (pck > 1000 * i * i * i)
>  			ctx->pck_min = max(pck - 1000 * i * i * i, 0lu);
>  		else
>