Re: [PATCH 1/2] drm/i915: Check VBIOS value for determining LVDS dual channel mode, too

[Keith Packard <keithp@keithp.com>]

<#part sign=pgpmime>
On Fri, 16 Mar 2012 22:41:12 +0100, Takashi Iwai <tiwai@suse.de> wrote:

> +/* read the initial LVDS register value for the given panel mode */
> +static unsigned int get_lvds_reg_val(const struct bdb_header *bdb,
> +				     const struct bdb_lvds_lfp_data_ptrs *ptrs,
> +				     int index,
> +				     struct drm_display_mode *mode)

To follow the style of intel_bios.c, I think it would make sense to have
the function:

static const struct lvds_dvo_timing *
get_lvds_fp_timing(const struct bdb_lvds_lfp_data *lvds_lfp_data,
        	   const struct bdb_lvds_lfp_data_ptrs *lvds_lfp_data_ptrs,
                   int index)

then use the results of this in parse_lfp_panel_data, instead of putting
the whole computation into this new function.

I'd also like to see this code only use the BDB value when the LVDS is
disabled at startup time; otherwise, we'll be changing the behavior for
all LVDS users, and as BIOS tables are notoriously unreliable, I fear
that we'll cause a lot more problems than we solve.

-- 
keith.packard@intel.com