Re: [Linux-fbdev-devel] [PATCH] nvidiafb: allow ignoring EDID info

From: Antonino A. Daplas
Date: Thu Feb 22 2007 - 03:38:25 EST


On Thu, 2007-02-22 at 09:01 +0100, Giuseppe Bilotta wrote:
> On 2/22/07, Antonino A. Daplas <adaplas@xxxxxxxxx> wrote:
> > On Wed, 2007-02-07 at 00:08 +0100, Giuseppe Bilotta wrote:
> > >
> > > As mentioned in another post in this thread, I can't get any info out
> > > of the i2c busses, because even when I have them available (i.e. after
> > > loading nvidiafb) I get XXXX all around (on all three of them).
> > > Suggestions on how to get the information welcome.
> >
> > Is this the same monitor you posted here?
> >
> > http://marc.theaimsgroup.com/?l=linux-kernel&m=112807065616218&w=2
> >
> > If yes, we already have the manufacturer and model code. The main
> > problem is that the EDID of this display has no sync range (H: 75-75kHz
> > and V: 60-60Hz). Extending Hsync from 30-75kHz as a fix to the EDID
> > block shouldn't be too hard.
>
> Yes, that's it! Jeepers, I can't believe that even re-reading the past
> LKML posts (even those!) I couldn't find the EDID info and how we had
> gotten them. I guess I need stronger glasses.
>
> Wonder why Luca's proposed patch makes the EDID undetectable, now, and
> why can't it be retrieved at a later time via i2c. Timeouts too small?
>
> > I already have a patch for this which I forgot to send to you
> > before :-). If you can confirm that this is still the same hardware,
> > I'll send you a test patch
>
> Yes, it's the same hardware. I can try the patch, with or without Luca's.
>
>

Okay. Patch attached. You may want to #define DEBUG in
drivers/video/fbmon.c so we can appreciate what happens. Load nvidiafb
with DEBUG defined before and after applying the patch, then send your
'dmesg'.

Tony
fbdev: Add Ultrasharp UXGA to broken monitor database

From: <>

This particular monitor does not have a limits block and has only one set of
monitor timings. Fix by adding a limits block to the EDID and extend the
horizontal sync frequency range to 30 kHz and 75 Khz.

Signed-off-by: Antonino Daplas <adaplas@xxxxxxxxx>
---

drivers/video/fbmon.c | 168 +++++++++++++++++++++++++++++++++----------------
1 files changed, 112 insertions(+), 56 deletions(-)

diff --git a/drivers/video/fbmon.c b/drivers/video/fbmon.c
index 6b385c3..05a9464 100644
--- a/drivers/video/fbmon.c
+++ b/drivers/video/fbmon.c
@@ -48,8 +48,9 @@ #else
#define DPRINTK(fmt, args...)
#endif

-#define FBMON_FIX_HEADER 1
-#define FBMON_FIX_INPUT 2
+#define FBMON_FIX_HEADER 1
+#define FBMON_FIX_INPUT 2
+#define FBMON_FIX_TIMINGS 3

#ifdef CONFIG_FB_MODE_HELPERS
struct broken_edid {
@@ -71,6 +72,12 @@ static const struct broken_edid brokendb
.model = 0x5a44,
.fix = FBMON_FIX_INPUT,
},
+ /* Sharp UXGA? */
+ {
+ .manufacturer = "SHP",
+ .model = 0x138e,
+ .fix = FBMON_FIX_TIMINGS,
+ },
};

static const unsigned char edid_v1_header[] = { 0x00, 0xff, 0xff, 0xff,
@@ -87,6 +94,55 @@ static void copy_string(unsigned char *c
while (i-- && (*--s == 0x20)) *s = 0;
}

+static int edid_is_serial_block(unsigned char *block)
+{
+ if ((block[0] == 0x00) && (block[1] == 0x00) &&
+ (block[2] == 0x00) && (block[3] == 0xff) &&
+ (block[4] == 0x00))
+ return 1;
+ else
+ return 0;
+}
+
+static int edid_is_ascii_block(unsigned char *block)
+{
+ if ((block[0] == 0x00) && (block[1] == 0x00) &&
+ (block[2] == 0x00) && (block[3] == 0xfe) &&
+ (block[4] == 0x00))
+ return 1;
+ else
+ return 0;
+}
+
+static int edid_is_limits_block(unsigned char *block)
+{
+ if ((block[0] == 0x00) && (block[1] == 0x00) &&
+ (block[2] == 0x00) && (block[3] == 0xfd) &&
+ (block[4] == 0x00))
+ return 1;
+ else
+ return 0;
+}
+
+static int edid_is_monitor_block(unsigned char *block)
+{
+ if ((block[0] == 0x00) && (block[1] == 0x00) &&
+ (block[2] == 0x00) && (block[3] == 0xfc) &&
+ (block[4] == 0x00))
+ return 1;
+ else
+ return 0;
+}
+
+static int edid_is_timing_block(unsigned char *block)
+{
+ if ((block[0] != 0x00) || (block[1] != 0x00) ||
+ (block[2] != 0x00) || (block[4] != 0x00))
+ return 1;
+ else
+ return 0;
+}
+
static int check_edid(unsigned char *edid)
{
unsigned char *block = edid + ID_MANUFACTURER_NAME, manufacturer[4];
@@ -104,9 +160,6 @@ static int check_edid(unsigned char *edi
for (i = 0; i < ARRAY_SIZE(brokendb); i++) {
if (!strncmp(manufacturer, brokendb[i].manufacturer, 4) &&
brokendb[i].model == model) {
- printk("fbmon: The EDID Block of "
- "Manufacturer: %s Model: 0x%x is known to "
- "be broken,\n", manufacturer, model);
fix = brokendb[i].fix;
break;
}
@@ -115,8 +168,10 @@ static int check_edid(unsigned char *edi
switch (fix) {
case FBMON_FIX_HEADER:
for (i = 0; i < 8; i++) {
- if (edid[i] != edid_v1_header[i])
+ if (edid[i] != edid_v1_header[i]) {
ret = fix;
+ break;
+ }
}
break;
case FBMON_FIX_INPUT:
@@ -126,14 +181,33 @@ static int check_edid(unsigned char *edi
if (b[4] & 0x01 && b[0] & 0x80)
ret = fix;
break;
+ case FBMON_FIX_TIMINGS:
+ b = edid + DETAILED_TIMING_DESCRIPTIONS_START;
+
+ for (i = 0; i < 4; i++) {
+ if (edid_is_limits_block(b)) {
+ ret = fix;
+ break;
+ }
+
+ b += DETAILED_TIMING_DESCRIPTION_SIZE;
+ }
+
+ break;
}

+ if (ret)
+ printk("fbmon: The EDID Block of "
+ "Manufacturer: %s Model: 0x%x is known to "
+ "be broken,\n", manufacturer, model);
+
return ret;
}

static void fix_edid(unsigned char *edid, int fix)
{
- unsigned char *b;
+ int i;
+ unsigned char *b, csum = 0;

switch (fix) {
case FBMON_FIX_HEADER:
@@ -145,6 +219,37 @@ static void fix_edid(unsigned char *edid
b = edid + EDID_STRUCT_DISPLAY;
b[0] &= ~0x80;
edid[127] += 0x80;
+ break;
+ case FBMON_FIX_TIMINGS:
+ printk("fbmon: trying to fix monitor timings\n");
+ b = edid + DETAILED_TIMING_DESCRIPTIONS_START;
+ for (i = 0; i < 4; i++) {
+ if (!(edid_is_serial_block(b) ||
+ edid_is_ascii_block(b) ||
+ edid_is_monitor_block(b) ||
+ edid_is_timing_block(b))) {
+ b[0] = 0x00;
+ b[1] = 0x00;
+ b[2] = 0x00;
+ b[3] = 0xfd;
+ b[4] = 0x00;
+ b[5] = 60; /* vfmin */
+ b[6] = 60; /* vfmax */
+ b[7] = 30; /* hfmin */
+ b[8] = 75; /* hfmax */
+ b[9] = 17; /* pixclock - 170 MHz*/
+ b[10] = 0; /* GTF */
+ break;
+ }
+
+ b += DETAILED_TIMING_DESCRIPTION_SIZE;
+ }
+
+ for (i = 0; i < EDID_LENGTH - 1; i++)
+ csum += edid[i];
+
+ edid[127] = 256 - csum;
+ break;
}
}

@@ -273,46 +378,6 @@ static void get_chroma(unsigned char *bl
DPRINTK("WhiteY: 0.%03d\n", specs->chroma.whitey);
}

-static int edid_is_serial_block(unsigned char *block)
-{
- if ((block[0] == 0x00) && (block[1] == 0x00) &&
- (block[2] == 0x00) && (block[3] == 0xff) &&
- (block[4] == 0x00))
- return 1;
- else
- return 0;
-}
-
-static int edid_is_ascii_block(unsigned char *block)
-{
- if ((block[0] == 0x00) && (block[1] == 0x00) &&
- (block[2] == 0x00) && (block[3] == 0xfe) &&
- (block[4] == 0x00))
- return 1;
- else
- return 0;
-}
-
-static int edid_is_limits_block(unsigned char *block)
-{
- if ((block[0] == 0x00) && (block[1] == 0x00) &&
- (block[2] == 0x00) && (block[3] == 0xfd) &&
- (block[4] == 0x00))
- return 1;
- else
- return 0;
-}
-
-static int edid_is_monitor_block(unsigned char *block)
-{
- if ((block[0] == 0x00) && (block[1] == 0x00) &&
- (block[2] == 0x00) && (block[3] == 0xfc) &&
- (block[4] == 0x00))
- return 1;
- else
- return 0;
-}
-
static void calc_mode_timings(int xres, int yres, int refresh,
struct fb_videomode *mode)
{
@@ -795,15 +860,6 @@ static void get_monspecs(unsigned char *
}
}

-static int edid_is_timing_block(unsigned char *block)
-{
- if ((block[0] != 0x00) || (block[1] != 0x00) ||
- (block[2] != 0x00) || (block[4] != 0x00))
- return 1;
- else
- return 0;
-}
-
int fb_parse_edid(unsigned char *edid, struct fb_var_screeninfo *var)
{
int i;