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SubjectRe: [Linux-fbdev-devel] [RFC][PATCH][FBDEV]: Setting fbcon's windows size
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On Mon, 2003-01-06 at 22:54, Antonino Daplas wrote:
> So, what's needed is a function that calculates timing parameters which
> is generic enough to work with the most common monitors. One solution
> is to use VESA's GTF (Generalized Timing Formula). Attached is a patch
> that implements the formula.
>

James,

Attached is a diff against linux-2.5.54 + your latest fbdev.diff.
Hopefully it's the final installment for the GTF implementation.

The fb_get_mode() function checks for a bit in 'flags' (FB_IGNOREMON) so
it will generate GTF timings regardless of the validity of
info->monspecs. This way, drivers can still use GTF even if they don't
have the operational limits of the monitor. They'll just decide what is
a practical safe limit.

This particular code snippet can be inserted in xxxfb_check_var() after
rounding off var->xres and var->yres.

...
if (fb_validate_mode(var, info)) {
if (!info->monspecs.hfmax || !info->monspecs.vfmax ||
!info->monspecs.dclkmax ||
info->monspecs.hfmax < info->monspecs.hfmin ||
info->monspecs.vfmax < info->monspecs.vfmin ||
info->monspecs.dclkmax < info->monspecs.dclkmin)
fb_get_mode(FB_IGNOREMON | FB_VSYNCTIMINGS, 60, var, info);
else
if (fb_get_mode(FB_MAXTIMINGS, 0, var, info))
return -EINVAL;
}
...

With the above, the driver will switch to a 60Hz refresh rate timings
(safe even for low-end monitors up to 1024x768) if monspecs is invalid.

Other changes: added a few more fields to fb_info.monspecs.

Tony

diff -Naur linux-2.5.54/drivers/video/fbmon.c linux/drivers/video/fbmon.c
--- linux-2.5.54/drivers/video/fbmon.c 2003-01-10 15:17:22.000000000 +0000
+++ linux/drivers/video/fbmon.c 2003-01-10 15:10:44.000000000 +0000
@@ -511,6 +511,9 @@
* refresh rate. Otherwise, it will calculate timings based on
* the flag and accompanying value.
*
+ * If FB_IGNOREMON bit is set in @flags, monitor specs will be
+ * ignored and @var will be filled with the calculated timings.
+ *
* All calculations are based on the VESA GTF Spreadsheet
* available at VESA's public ftp (http://www.vesa.org).
*
@@ -527,22 +530,27 @@
{
struct __fb_timings timings;
u32 interlace = 1, dscan = 1;
- u32 hfmin, hfmax, vfmin, vfmax;
+ u32 hfmin, hfmax, vfmin, vfmax, dclkmin, dclkmax;

/*
* If monspecs are invalid, use values that are enough
* for 640x480@60
*/
- if ((!info->monspecs.hfmax && !info->monspecs.vfmax) ||
+ if (!info->monspecs.hfmax || !info->monspecs.vfmax ||
+ !info->monspecs.dclkmax ||
info->monspecs.hfmax < info->monspecs.hfmin ||
- info->monspecs.vfmax < info->monspecs.vfmin) {
+ info->monspecs.vfmax < info->monspecs.vfmin ||
+ info->monspecs.dclkmax < info->monspecs.dclkmin) {
hfmin = 29000; hfmax = 30000;
vfmin = 60; vfmax = 60;
+ dclkmin = 0; dclkmax = 25000000;
} else {
hfmin = info->monspecs.hfmin;
hfmax = info->monspecs.hfmax;
vfmin = info->monspecs.vfmin;
vfmax = info->monspecs.vfmax;
+ dclkmin = info->monspecs.dclkmin;
+ dclkmax = info->monspecs.dclkmax;
}

memset(&timings, 0, sizeof(struct __fb_timings));
@@ -557,8 +565,8 @@
dscan = 2;
}

- switch (flags) {
- case 0: /* maximize refresh rate */
+ switch (flags & ~FB_IGNOREMON) {
+ case FB_MAXTIMINGS: /* maximize refresh rate */
timings.hfreq = hfmax;
fb_timings_hfreq(&timings);
if (timings.vfreq > vfmax) {
@@ -566,15 +574,15 @@
fb_timings_vfreq(&timings);
}
break;
- case 1: /* vrefresh driven */
+ case FB_VSYNCTIMINGS: /* vrefresh driven */
timings.vfreq = val;
fb_timings_vfreq(&timings);
break;
- case 2: /* hsync driven */
+ case FB_HSYNCTIMINGS: /* hsync driven */
timings.hfreq = val;
fb_timings_hfreq(&timings);
break;
- case 3: /* pixelclock driven */
+ case FB_DCLKTIMINGS: /* pixelclock driven */
timings.dclk = PICOS2KHZ(val) * 1000;
fb_timings_dclk(&timings);
break;
@@ -583,11 +591,12 @@

}

- if (timings.vfreq < vfmin || timings.vfreq > vfmax ||
- timings.hfreq < hfmin || timings.hfreq > hfmax)
+ if (!(flags & FB_IGNOREMON) &&
+ (timings.vfreq < vfmin || timings.vfreq > vfmax ||
+ timings.hfreq < hfmin || timings.hfreq > hfmax ||
+ timings.dclk < dclkmin || timings.dclk > dclkmax))
return -EINVAL;

-
var->pixclock = KHZ2PICOS(timings.dclk/1000);
var->hsync_len = (timings.htotal * 8)/100;
var->right_margin = (timings.hblank/2) - var->hsync_len;
@@ -616,22 +625,27 @@
int fb_validate_mode(struct fb_var_screeninfo *var, struct fb_info *info)
{
u32 hfreq, vfreq, htotal, vtotal, pixclock;
- u32 hfmin, hfmax, vfmin, vfmax;
+ u32 hfmin, hfmax, vfmin, vfmax, dclkmin, dclkmax;

/*
* If monspecs are invalid, use values that are enough
* for 640x480@60
*/
- if ((!info->monspecs.hfmax && !info->monspecs.vfmax) ||
+ if (!info->monspecs.hfmax || !info->monspecs.vfmax ||
+ !info->monspecs.dclkmax ||
info->monspecs.hfmax < info->monspecs.hfmin ||
- info->monspecs.vfmax < info->monspecs.vfmin) {
+ info->monspecs.vfmax < info->monspecs.vfmin ||
+ info->monspecs.dclkmax < info->monspecs.dclkmin) {
hfmin = 29000; hfmax = 30000;
vfmin = 60; vfmax = 60;
+ dclkmin = 0; dclkmax = 25000000;
} else {
hfmin = info->monspecs.hfmin;
hfmax = info->monspecs.hfmax;
vfmin = info->monspecs.vfmin;
vfmax = info->monspecs.vfmax;
+ dclkmin = info->monspecs.dclkmin;
+ dclkmax = info->monspecs.dclkmax;
}

if (!var->pixclock)
diff -Naur linux-2.5.54/include/linux/fb.h linux/include/linux/fb.h
--- linux-2.5.54/include/linux/fb.h 2003-01-10 15:17:37.000000000 +0000
+++ linux/include/linux/fb.h 2003-01-10 15:19:56.000000000 +0000
@@ -240,6 +240,9 @@
__u32 hfmax; /* hfreq upper limit (Hz) */
__u16 vfmin; /* vfreq lower limit (Hz) */
__u16 vfmax; /* vfreq upper limit (Hz) */
+ __u32 dclkmin; /* pixelclock lower limit (Hz) */
+ __u32 dclkmax; /* pixelclock upper limit (Hz) */
+ unsigned gtf : 1; /* supports GTF */
unsigned dpms : 1; /* supports DPMS */
};

@@ -465,6 +468,12 @@
extern int num_registered_fb;

/* drivers/video/fbmon.c */
+#define FB_MAXTIMINGS 0
+#define FB_VSYNCTIMINGS 1
+#define FB_HSYNCTIMINGS 2
+#define FB_DCLKTIMINGS 3
+#define FB_IGNOREMON 0x100
+
extern int fbmon_valid_timings(u_int pixclock, u_int htotal, u_int vtotal,
const struct fb_info *fb_info);
extern int fbmon_dpms(const struct fb_info *fb_info);
-
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