commit bd92b18d18604d2dd846473290a62aaaeebf732b
Author: Andriy Gapon <avg@icyb.net.ua>
Date:   Fri Apr 13 19:16:59 2012 +0300

    intel_iic: correct the comment
    
    we should always restore slave address back to the original format
    in case there will be retries or other repeated executions of the command

diff --git a/sys/dev/drm/intel_iic.c b/sys/dev/drm/intel_iic.c
index b82b6cb..2dac132 100644
--- a/sys/dev/drm/intel_iic.c
+++ b/sys/dev/drm/intel_iic.c
@@ -393,7 +393,7 @@ intel_iic_quirk_xfer(device_t idev, struct iic_msg *msgs, int nmsgs)
 			 msgs[i].flags |= IIC_M_NOSTOP;
 	}
 	ret = iicbus_transfer(idev, msgs, nmsgs);
-	/* restore just in case */
+	/* restore the addresses */
 	for (i = 0; i < nmsgs; i++)
 		msgs[i].slave >>= 1;
 	IICBB_SETSDA(bridge_dev, 1);

commit 6c90d1dcc322fae58c21f8973db99fc14f8d0718
Author: Andriy Gapon <avg@icyb.net.ua>
Date:   Fri Apr 13 19:11:21 2012 +0300

    intel_iic_quirk_xfer: force use of repeated start within a transaction
    
    This behavior is default on Linux, but on FreeBSD we issue stop and start
    between individual messages of a transaction.
    The distinction is important for SDVO I2C control bus switch case.
    The hardware switches back from DDC bus when it sees a stop bit and so
    the stop bit should appear only at the very end of a transaction intended
    for the DDC bus.

diff --git a/sys/dev/drm/intel_iic.c b/sys/dev/drm/intel_iic.c
index 1e171a2..b82b6cb 100644
--- a/sys/dev/drm/intel_iic.c
+++ b/sys/dev/drm/intel_iic.c
@@ -386,8 +386,12 @@ intel_iic_quirk_xfer(device_t idev, struct iic_msg *msgs, int nmsgs)
 	DELAY(I2C_RISEFALL_TIME);
 
 	/* convert slave addresses to format expected by iicbb */
-	for (i = 0; i < nmsgs; i++)
+	for (i = 0; i < nmsgs; i++) {
 		msgs[i].slave <<= 1;
+		/* force use of repeated start instead of default stop+start */
+		if (i != (nmsgs - 1))
+			 msgs[i].flags |= IIC_M_NOSTOP;
+	}
 	ret = iicbus_transfer(idev, msgs, nmsgs);
 	/* restore just in case */
 	for (i = 0; i < nmsgs; i++)
commit 348fe0fb0cdf81ec3c1e99e9426f8feee8584e17
Author: Andriy Gapon <avg@icyb.net.ua>
Date:   Fri Apr 13 19:56:58 2012 +0300

    drm_edid: print a debug message only when there is an error

diff --git a/sys/dev/drm/drm_edid.c b/sys/dev/drm/drm_edid.c
index 0ee0647..3bc2fb8 100644
--- a/sys/dev/drm/drm_edid.c
+++ b/sys/dev/drm/drm_edid.c
@@ -272,8 +272,9 @@ drm_do_probe_ddc_edid(device_t adapter, unsigned char *buf,
 			}
 		};
 		ret = iicbus_transfer(adapter, msgs, 2);
-		DRM_DEBUG_KMS("iicbus_transfer countdown %d error %d\n",
-		    retries, ret);
+		if (ret != 0)
+			DRM_DEBUG_KMS("iicbus_transfer countdown %d error %d\n",
+			    retries, ret);
 	} while (ret != 0 && --retries);
 
 	return (ret == 0 ? 0 : -1);