From: Octavian Purdila <octavian.purdila@intel.com>
Date: Fri, 15 Jul 2011 16:34:15 +0000 (+0100)
Subject: gma500: skip getting modes via DDC on Moorestown
X-Git-Tag: firefly_0821_release~3680^2~4924^2~22
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=6e4b308a286821458633a90b82d63d2ce7e742b5;p=firefly-linux-kernel-4.4.55.git

gma500: skip getting modes via DDC on Moorestown

Moorestown does not have a DDC bus, skip getting modes via DDC. This
fixes the following bug:

BUG: unable to handle kernel NULL pointer dereference at 00000010
IP: [<c1172ff7>] i2c_transfer+0x17/0xb0
*pde = 00000000
Oops: 0000 [#1]

Call Trace:
 [<c1153ae9>] drm_do_probe_ddc_edid+0x59/0x90
 [<c1153cb4>] drm_get_edid+0x24/0x250
 [<c11805d2>] psb_intel_ddc_get_modes+0x22/0x60
 [<c117fe11>] psb_intel_lvds_get_modes+0x21/0x80

Signed-off-by: Octavian Purdila <octavian.purdila@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/drivers/staging/gma500/psb_intel_lvds.c b/drivers/staging/gma500/psb_intel_lvds.c
index da6f5c89e5e7..53803b25cadb 100644
--- a/drivers/staging/gma500/psb_intel_lvds.c
+++ b/drivers/staging/gma500/psb_intel_lvds.c
@@ -521,7 +521,8 @@ static int psb_intel_lvds_get_modes(struct drm_connector *connector)
 					psb_intel_output->mode_dev;
 	int ret = 0;
 
-	ret = psb_intel_ddc_get_modes(psb_intel_output);
+	if (!IS_MRST(dev))
+		ret = psb_intel_ddc_get_modes(psb_intel_output);
 
 	if (ret)
 		return ret;