[PATCH] modes: improve aspect ratio match for classic drivers

[Alex Deucher]

On Mon, Oct 4, 2010 at 3:59 PM, Adam Jackson <ajax at redhat.com> wrote:
> From: Olivier Fourdan <ofourdan at redhat.com>
>
> After we infer the aspect ratio for the screen, we pick the largest
> mode matching that aspect ratio from the best mode pool available.
> We then clamp virtual size to that mode, and run the resulting mode
> list through the driver's ValidMode hook.  In doing so we might filter
> away our initial guess.  If this happens we shrink the default mode
> to the next largest mode from _any_ mode pool.  This is usually wrong,
> and we should instead pick the next aspect-matched mode from the best
> available mode pool (as always, user then driver then default).
>
> Originally reported as http://bugzilla.redhat.com/604057
>
> Signed-off-by: Adam Jackson <ajax at redhat.com>

Looks reasonable.

Reviewed-by: Alex Deucher <alexdeucher at gmail.com>

> ---
>  hw/xfree86/common/xf86Mode.c |   64 ++++++++++++++++++++++++++++++++++++++---
>  1 files changed, 59 insertions(+), 5 deletions(-)
>
> diff --git a/hw/xfree86/common/xf86Mode.c b/hw/xfree86/common/xf86Mode.c
> index 7bdf79a..514a2e2 100644
> --- a/hw/xfree86/common/xf86Mode.c
> +++ b/hw/xfree86/common/xf86Mode.c
> @@ -1831,8 +1831,6 @@ xf86ValidateModes(ScrnInfoPtr scrp, DisplayModePtr availModes,
>        numModes++;
>     }
>
> -#undef _VIRTUALX
> -
>     /*
>      * If we estimated the virtual size above, we may have filtered away all
>      * the modes that maximally match that size; scan again to find out and
> @@ -1847,13 +1845,69 @@ xf86ValidateModes(ScrnInfoPtr scrp, DisplayModePtr availModes,
>            }
>        }
>        if (vx < virtX || vy < virtY) {
> +           const int types[] = {
> +               M_T_BUILTIN | M_T_PREFERRED,
> +               M_T_BUILTIN,
> +               M_T_DRIVER | M_T_PREFERRED,
> +               M_T_DRIVER,
> +               0
> +           };
> +           const int ntypes = sizeof(types) / sizeof(int);
> +           int n;
> +
> +           /*
> +            * We did not find the estimated virtual size. So now we want to
> +            * find the largest mode available, but we want to search in the
> +            * modes in the order of "types" listed above.
> +            */
> +           for (n = 0; n < ntypes; n++) {
> +               int type = types[n];
> +
> +               vx = 0; vy = 0;
> +               for (p = scrp->modes; p; p = p->next) {
> +                   /* scan through the modes in the sort order above */
> +                   if ((p->type & type) != type)
> +                       continue;
> +                   if (p->HDisplay > vx && p->VDisplay > vy) {
> +                       vx = p->HDisplay;
> +                       vy = p->VDisplay;
> +                   }
> +               }
> +               if (vx && vy)
> +                   /* Found one */
> +                   break;
> +           }
>            xf86DrvMsg(scrp->scrnIndex, X_WARNING,
>                       "Shrinking virtual size estimate from %dx%d to %dx%d\n",
>                       virtX, virtY, vx, vy);
> -           virtX = vx;
> +           virtX = _VIRTUALX(vx);
>            virtY = vy;
> -           linePitch = scanLineWidth(vx, vy, minPitch, apertureSize,
> -                                     BankFormat, pitchInc);
> +           for (p = scrp->modes; p; p = p->next) {
> +               if (numModes > 0) {
> +                   if (p->HDisplay > virtX)
> +                       p->status = MODE_VIRTUAL_X;
> +                   if (p->VDisplay > virtY)
> +                       p->status = MODE_VIRTUAL_Y;
> +                   if (p->status != MODE_OK) {
> +                       numModes--;
> +                       printModeRejectMessage(scrp->scrnIndex, p, p->status);
> +                   }
> +               }
> +           }
> +           if (linePitches != NULL) {
> +               for (i = 0; linePitches[i] != 0; i++) {
> +                   if ((linePitches[i] >= virtX) &&
> +                       (linePitches[i] ==
> +                       scanLineWidth(virtX, virtY, linePitches[i],
> +                                     apertureSize, BankFormat, pitchInc))) {
> +                       linePitch = linePitches[i];
> +                       break;
> +                   }
> +               }
> +           } else {
> +               linePitch = scanLineWidth(virtX, virtY, minPitch,
> +                                         apertureSize, BankFormat, pitchInc);
> +           }
>        }
>     }
>
> --
> 1.7.2.2
>
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