Re: [PATCH 1/4] fbdev: make fb_find_mode look for a mode with thehighest refresh rate

From: Andrew Morton
Date: Sat Jun 23 2007 - 14:05:26 EST


On Sat, 23 Jun 2007 12:50:46 +0200 Michal Januszewski <spock@xxxxxxxxxx> wrote:

> If the refresh rate hasn't been explicitly specified, fd_find_mode
> currently returns the first mode with the requested resolution. Change
> it so that it returns a mode with the requested resolution and the
> highest refresh rate.
>
> Also export fb_destroy_modelist, which is used in uvesafb.
>
> Signed-off-by: Michal Januszewski <spock@xxxxxxxxxx>
> ---
> drivers/video/modedb.c | 7 +++++--
> 1 files changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/video/modedb.c b/drivers/video/modedb.c
> index 3741ad7..98ee77b 100644
> --- a/drivers/video/modedb.c
> +++ b/drivers/video/modedb.c
> @@ -606,16 +606,18 @@ done:
> DPRINTK("Trying specified video mode%s %ix%i\n",
> refresh_specified ? "" : " (ignoring refresh rate)", xres, yres);
>
> + if (!refresh_specified)
> + refresh = 200;
> diff = refresh;
> best = -1;
> for (i = 0; i < dbsize; i++) {
> if (name_matches(db[i], name, namelen) ||
> (res_specified && res_matches(db[i], xres, yres))) {
> if(!fb_try_mode(var, info, &db[i], bpp)) {
> - if(!refresh_specified || db[i].refresh == refresh)
> + if (refresh_specified && db[i].refresh == refresh)
> return 1;
> else {
> - if(diff > abs(db[i].refresh - refresh)) {
> + if (diff > abs(db[i].refresh - refresh)) {
> diff = abs(db[i].refresh - refresh);
> best = i;
> }
> @@ -938,6 +940,7 @@ void fb_destroy_modelist(struct list_head *head)
> kfree(pos);
> }
> }
> +EXPORT_SYMBOL_GPL(fb_destroy_modelist);
>

fbdev ignoramus asks: isn't this pretty risky? People who were previously
relying upon (or at least using) the kernel's default resolution will find
their displays coming up in a quite different resolution.

This change seems to be quite unrelated to the uvesafb stuff and should be
in a separate patch from the export, which _is_ uvesafb-related. I think.
If that's wrong then the changelog could do with some attention.

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