[PATCH] i810fb: Do not probe the third i2c bus by default

Some time before 2.6.15, a third DDC channel was added to i810fb.  On
systems where these ddc pins are not connected, the probe takes about 10
seconds.

Add a boot/module option for i810fb to explicitly probe for the 3rd ddc bus
if needed.

Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

3 files changed, 14 insertions, 6 deletions

diff --git a/drivers/video/i810/i810-i2c.c b/drivers/video/i810/i810-i2c.c
index bd410e06db73..e3c8b5f1ca76 100644
--- a/drivers/video/i810/i810-i2c.c
+++ b/drivers/video/i810/i810-i2c.c
@@ -191,11 +191,11 @@ int i810_probe_i2c_connector(struct fb_info *info, u8 **out_edid, int conn)
         u8 *edid = NULL;
         int i;
 
-        DPRINTK("i810-i2c: Probe DDC%i Bus\n", conn);
-        if (conn < 4) {
+        DPRINTK("i810-i2c: Probe DDC%i Bus\n", conn+1);
+        if (conn < par->ddc_num) {
                 for (i = 0; i < 3; i++) {
                         /* Do the real work */
-                        edid = i810_do_probe_i2c_edid(&par->chan[conn-1]);
+                        edid = i810_do_probe_i2c_edid(&par->chan[conn]);
                         if (edid)
                                 break;
                 }
diff --git a/drivers/video/i810/i810.h b/drivers/video/i810/i810.h
index 6c187d5fe951..579195c2bea3 100644
--- a/drivers/video/i810/i810.h
+++ b/drivers/video/i810/i810.h
@@ -280,6 +280,7 @@ struct i810fb_par {
         u32 blit_bpp;
         u32 ovract;
         u32 cur_state;
+        u32 ddc_num;
         int mtrr_reg;
         u16 bltcntl;
         u8 interlace;
diff --git a/drivers/video/i810/i810_main.c b/drivers/video/i810/i810_main.c
index 266d0ab92663..d8467c03b49f 100644
--- a/drivers/video/i810/i810_main.c
+++ b/drivers/video/i810/i810_main.c
@@ -149,6 +149,7 @@ static int vyres      __devinitdata;
 static int sync       __devinitdata;
 static int extvga     __devinitdata;
 static int dcolor     __devinitdata;
+static int ddc3       __devinitdata = 2;
 
 /*------------------------------------------------------------*/
 
@@ -1763,6 +1764,8 @@ static void __devinit i810_init_defaults(struct i810fb_par *par,
         if (sync) 
                 par->dev_flags |= ALWAYS_SYNC;
 
+        par->ddc_num = ddc3;
+
         if (bpp < 8)
                 bpp = 8;
         
@@ -1885,7 +1888,7 @@ static void __devinit i810fb_find_init_mode(struct fb_info *info)
         int found = 0;
 #ifdef CONFIG_FB_I810_I2C
         int i;
-        int err;
+        int err = 1;
         struct i810fb_par *par = info->par;
 #endif
 
@@ -1895,8 +1898,8 @@ static void __devinit i810fb_find_init_mode(struct fb_info *info)
 #ifdef CONFIG_FB_I810_I2C
         i810_create_i2c_busses(par);
 
-        for (i = 0; i < 4; i++) {
-                err = i810_probe_i2c_connector(info, &par->edid, i+1);
+        for (i = 0; i < par->ddc_num + 1; i++) {
+                err = i810_probe_i2c_connector(info, &par->edid, i);
                 if (!err)
                         break;
         }
@@ -1983,6 +1986,8 @@ static int __devinit i810fb_setup(char *options)
                         vsync2 = simple_strtoul(this_opt+7, NULL, 0);
                 else if (!strncmp(this_opt, "dcolor", 6))
                         dcolor = 1;
+                else if (!strncmp(this_opt, "ddc3", 4))
+                        ddc3 = 3;
                 else
                         mode_option = this_opt;
         }
@@ -2190,6 +2195,8 @@ MODULE_PARM_DESC(sync, "wait for accel engine to finish drawing"
 module_param(dcolor, bool, 0);
 MODULE_PARM_DESC(dcolor, "use DirectColor visuals"
                  " (default = 0 = TrueColor)");
+module_param(ddc3, bool, 0);
+MODULE_PARM_DESC(ddc3, "Probe DDC bus 3 (default = 0 = no)");
 module_param(mode_option, charp, 0);
 MODULE_PARM_DESC(mode_option, "Specify initial video mode");