* [PATCH 8/13] fbdev: mac_var_to_mode() fix
@ 2009-11-03 13:43 Finn Thain
2009-11-03 17:00 ` David D. Kilzer
0 siblings, 1 reply; 3+ messages in thread
From: Finn Thain @ 2009-11-03 13:43 UTC (permalink / raw)
To: Geert Uytterhoeven; +Cc: linux-fbdev-devel, linux-m68k
The valkyriefb driver assumes that this logic holds:
mac_vmode_to_var(X, cmode, &var);
mac_var_to_vmode(&var, &vmode, &cmode);
assert(vmode == X);
But it doesn't hold because mac_var_to_vmode() can return a mode with a
slower pixel clock, even when a match is available. So we end up with this
failure:
using video mode 11 and color mode 0.
valkyriefb: vmode 12 not valid.
valkyriefb: can't set default video mode
valkyriefb: vmode 12 not valid.
Rather than have mac_var_to_mode() return the first reasonable mode it
finds, have it return the mode that is closest to the requested one (or
the mode with the closest longer pixel clock period if there is no exact
match).
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
---
drivers/video/macmodes.c | 40 +++++++++++++++++++++++++++++++---------
1 file changed, 31 insertions(+), 9 deletions(-)
Index: linux-2.6.31/drivers/video/macmodes.c
===================================================================
--- linux-2.6.31.orig/drivers/video/macmodes.c 2009-11-03 03:23:24.000000000 +1100
+++ linux-2.6.31/drivers/video/macmodes.c 2009-11-03 03:23:43.000000000 +1100
@@ -134,7 +134,7 @@ static const struct fb_videomode mac_mod
*
* These MUST be ordered in
* - increasing resolution
- * - decreasing refresh rate
+ * - decreasing pixel clock period
*/
static const struct mode_map {
@@ -142,20 +142,20 @@ static const struct mode_map {
const struct fb_videomode *mode;
} mac_modes[] = {
/* 640x480 */
- { VMODE_640_480_67, &mac_modedb[1] },
{ VMODE_640_480_60, &mac_modedb[0] },
+ { VMODE_640_480_67, &mac_modedb[1] },
/* 800x600 */
+ { VMODE_800_600_56, &mac_modedb[2] },
+ { VMODE_800_600_60, &mac_modedb[3] },
{ VMODE_800_600_75, &mac_modedb[5] },
{ VMODE_800_600_72, &mac_modedb[4] },
- { VMODE_800_600_60, &mac_modedb[3] },
- { VMODE_800_600_56, &mac_modedb[2] },
/* 832x624 */
{ VMODE_832_624_75, &mac_modedb[6] },
/* 1024x768 */
- { VMODE_1024_768_75, &mac_modedb[10] },
- { VMODE_1024_768_75V, &mac_modedb[9] },
- { VMODE_1024_768_70, &mac_modedb[8] },
{ VMODE_1024_768_60, &mac_modedb[7] },
+ { VMODE_1024_768_70, &mac_modedb[8] },
+ { VMODE_1024_768_75V, &mac_modedb[9] },
+ { VMODE_1024_768_75, &mac_modedb[10] },
/* 1152x768 */
{ VMODE_1152_768_60, &mac_modedb[14] },
/* 1152x870 */
@@ -299,7 +299,6 @@ EXPORT_SYMBOL(mac_vmode_to_var);
int mac_var_to_vmode(const struct fb_var_screeninfo *var, int *vmode,
int *cmode)
{
- const struct fb_videomode *mode = NULL;
const struct mode_map *map;
if (var->bits_per_pixel <= 8)
@@ -311,8 +310,13 @@ int mac_var_to_vmode(const struct fb_var
else
return -EINVAL;
+ /*
+ * Find the mac_mode with a matching resolution or failing that, the
+ * closest larger resolution. Skip modes with a shorter pixel clock period.
+ */
for (map = mac_modes; map->vmode != -1; map++) {
- mode = map->mode;
+ const struct fb_videomode *mode = map->mode;
+
if (var->xres > mode->xres || var->yres > mode->yres)
continue;
if (var->xres_virtual > mode->xres || var->yres_virtual > mode->yres)
@@ -322,6 +326,24 @@ int mac_var_to_vmode(const struct fb_var
if ((var->vmode & FB_VMODE_MASK) != mode->vmode)
continue;
*vmode = map->vmode;
+
+ /*
+ * Having found a good resolution, find the matching pixel clock
+ * or failing that, the closest longer pixel clock period.
+ */
+ map++;
+ while (map->vmode != -1) {
+ const struct fb_videomode *clk_mode = map->mode;
+
+ if (mode->xres != clk_mode->xres || mode->yres != clk_mode->yres)
+ break;
+ if (var->pixclock > mode->pixclock)
+ break;
+ if (mode->vmode != clk_mode->vmode)
+ continue;
+ *vmode = map->vmode;
+ map++;
+ }
return 0;
}
return -EINVAL;
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH 8/13] fbdev: mac_var_to_mode() fix
2009-11-03 13:43 [PATCH 8/13] fbdev: mac_var_to_mode() fix Finn Thain
@ 2009-11-03 17:00 ` David D. Kilzer
2009-11-04 0:48 ` Finn Thain
0 siblings, 1 reply; 3+ messages in thread
From: David D. Kilzer @ 2009-11-03 17:00 UTC (permalink / raw)
To: Finn Thain, Geert Uytterhoeven; +Cc: linux-fbdev-devel, linux-m68k
On Tue, November 3, 2009 at 5:43:16 AM, Finn Thain wrote:
> /* 800x600 */
> + { VMODE_800_600_56, &mac_modedb[2] },
> + { VMODE_800_600_60, &mac_modedb[3] },
> { VMODE_800_600_75, &mac_modedb[5] },
> { VMODE_800_600_72, &mac_modedb[4] },
> - { VMODE_800_600_60, &mac_modedb[3] },
> - { VMODE_800_600_56, &mac_modedb[2] },
I believe you want to swap VMODE_800_600_75 and VMODE_800_600_72 here as well.
Dave
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH 8/13] fbdev: mac_var_to_mode() fix
2009-11-03 17:00 ` David D. Kilzer
@ 2009-11-04 0:48 ` Finn Thain
0 siblings, 0 replies; 3+ messages in thread
From: Finn Thain @ 2009-11-04 0:48 UTC (permalink / raw)
To: David D. Kilzer; +Cc: Geert Uytterhoeven, linux-fbdev-devel, linux-m68k
On Tue, 3 Nov 2009, David D. Kilzer wrote:
> On Tue, November 3, 2009 at 5:43:16 AM, Finn Thain wrote:
>
> > /* 800x600 */
> > + { VMODE_800_600_56, &mac_modedb[2] },
> > + { VMODE_800_600_60, &mac_modedb[3] },
> > { VMODE_800_600_75, &mac_modedb[5] },
> > { VMODE_800_600_72, &mac_modedb[4] },
> > - { VMODE_800_600_60, &mac_modedb[3] },
> > - { VMODE_800_600_56, &mac_modedb[2] },
>
>
> I believe you want to swap VMODE_800_600_75 and VMODE_800_600_72 here as well.
In this case, the mode with the faster vertical refresh frequency actually
has the higher pixel clock period. So I think the patch is correct.
Finn
>
> Dave
>
^ permalink raw reply [flat|nested] 3+ messages in thread
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2009-11-03 13:43 [PATCH 8/13] fbdev: mac_var_to_mode() fix Finn Thain
2009-11-03 17:00 ` David D. Kilzer
2009-11-04 0:48 ` Finn Thain
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