Re: kern/49285 drmkms on pineview (intel)

[Patrick Welche <prlw1%cam.ac.uk@localhost>]

I connected the "broken" monitor above, which is detected by the pineview
as having a broken 0x00ffffff... EDID into a -current/amd64 Sandy Bridge
laptop, and happily used it as a second high resolution screen.

The Sandy Bridge managed to read its EDID successfully (including no
mention of bit banging).

I applied the following kludge:

Index: sys/external/bsd/drm2/dist/drm/drm_edid.c
===================================================================
RCS file: /cvsroot/src/sys/external/bsd/drm2/dist/drm/drm_edid.c,v
retrieving revision 1.4
diff -u -r1.4 drm_edid.c
--- sys/external/bsd/drm2/dist/drm/drm_edid.c   16 Jul 2014 20:56:24 -0000      1.4
+++ sys/external/bsd/drm2/dist/drm/drm_edid.c   17 Jun 2015 16:03:43 -0000
 EXPORT_SYMBOL(drm_edid_block_valid);
@@ -1282,10 +1284,28 @@
 struct edid *drm_get_edid(struct drm_connector *connector,
                          struct i2c_adapter *adapter)
 {
+       static const u8 rawedid[EDID_LENGTH] = {
+0x00,0xff,0xff,0xff,0xff,0xff,0xff,0x00,0x26,0xcd,0x0d,0x56,0x01,0x01,0x01,0x01,
+0x32,0x13,0x01,0x03,0x68,0x34,0x1e,0x78,0x2a,0xee,0xd5,0xa5,0x55,0x48,0x9b,0x26,
+0x12,0x50,0x54,0xbf,0xef,0x80,0xb3,0x00,0xa9,0x40,0x95,0x00,0x81,0x8f,0x81,0x80,
+0x95,0x0f,0x71,0x4f,0x01,0x01,0x94,0x43,0x80,0x90,0x72,0x38,0x28,0x40,0x80,0xc8,
+0x35,0x00,0x09,0x25,0x21,0x00,0x00,0x1c,0x00,0x00,0x00,0xff,0x00,0x31,0x31,0x30,
+0x30,0x31,0x39,0x35,0x30,0x35,0x30,0x30,0x34,0x30,0x00,0x00,0x00,0xfd,0x00,0x37,
+0x4c,0x1d,0x51,0x12,0x00,0x0a,0x20,0x20,0x20,0x20,0x20,0x20,0x00,0x00,0x00,0xfc,
+0x00,0x50,0x4c,0x45,0x32,0x34,0x30,0x37,0x48,0x44,0x53,0x0a,0x20,0x20,0x00,0xae
+       };
+
+/*
        struct edid *edid = NULL;
 
        if (drm_probe_ddc(adapter))
                edid = (struct edid *)drm_do_get_edid(connector, adapter);
+*/
+
+       struct edid *edid = kmalloc(EDID_LENGTH, GFP_KERNEL);
+
+       if (edid != NULL)
+               memcpy(edid, rawedid, EDID_LENGTH);
 
        return edid;
 }


and said pineview now does 1366x768 pixels on the "broken" monitor, (without
trying to disable the spurious LVDS1 connector)...

Sounds like this all boils down to a gmbus problem...