From 8316f33766a82907c694267ff911e45e256f09f9 Mon Sep 17 00:00:00 2001
From: David Flynn <davidf@rd.bbc.co.uk>
Date: Wed, 8 Dec 2010 16:10:21 +0000
Subject: [PATCH 1/5] drm/i915/dp: Fix I2C/EDID handling with active
 DisplayPort to DVI converter

The DisplayPort standard (1.1a) states that:
  The I2C-over-AUX Reply field is valid only when Native AUX CH Reply
  field is AUX_ACK (00). When Native AUX CH Reply field is not 00, then,
  I2C-over-AUX Reply field must be 00 and be ignored.

This fixes broken EDID reading when using an active DisplayPort to
duallink DVI converter.  If the AUX CH replier chooses to defer the
transaction, a short read occurs and erroneous data is returned as
the i2c reply due to a lack of length checking and failure to check
for AUX ACK.

As a result, broken EDIDs can look like:
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f    0123456789abcdef
00: bc bc bc ff bc bc bc ff bc bc bc ac bc bc bc 45    ???.???.???????E
10: bc bc bc 10 bc bc bc 34 bc bc bc ee bc bc bc 4c    ???????4???????L
20: bc bc bc 50 bc bc bc 00 bc bc bc 40 bc bc bc 00    ???P???.???@???.
30: bc bc bc 01 bc bc bc 01 bc bc bc a0 bc bc bc 40    ???????????????@
40: bc bc bc 00 bc bc bc 00 bc bc bc 00 bc bc bc 55    ???.???.???.???U
50: bc bc bc 35 bc bc bc 31 bc bc bc 20 bc bc bc fc    ???5???1??? ????
60: bc bc bc 4c bc bc bc 34 bc bc bc 46 bc bc bc 00    ???L???4???F???.
70: bc bc bc 38 bc bc bc 11 bc bc bc 20 bc bc bc 20    ???8??????? ???
80: bc bc bc ff bc bc bc ff bc bc bc ff bc bc bc ff    ???.???.???.???.
...

which can lead to:
[drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder
[drm:drm_edid_block_valid] *ERROR* Raw EDID:
<3>30 30 30 30 30 30 30 32 38 32 30 32 63 63 31 61  000000028202cc1a
<3>28 00 02 8c 00 00 00 00 18 00 00 00 00 00 00 00  (...............
<3>20 4c 61 73 74 20 62 65 61 63 6f 6e 3a 20 33 32   Last beacon: 32
<3>32 30 6d 73 20 61 67 6f 46 00 05 8c 00 00 00 00  20ms agoF.......
<3>36 00 00 00 00 00 00 00 00 0c 57 69 2d 46 69 20  6.........Wi-Fi
<3>52 6f 75 74 65 72 01 08 82 84 8b 96 24 30 48 6c  Router......$0Hl
<3>03 01 01 06 02 00 00 2a 01 00 2f 01 00 32 04 0c  .......*../..2..
<3>12 18 60 dd 09 00 10 18 02 00 00 01 00 00 18 00  ..`.............

Signed-off-by: David Flynn <davidf@rd.bbc.co.uk>
[ickle: fix up some surrounding checkpatch warnings]
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: stable@kernel.org
---
 drivers/gpu/drm/i915/intel_dp.c | 37 ++++++++++++++++++++++++++-------
 1 file changed, 30 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index df648cb4c2964..864417cffe9a7 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -479,6 +479,7 @@ intel_dp_i2c_aux_ch(struct i2c_adapter *adapter, int mode,
 	uint16_t address = algo_data->address;
 	uint8_t msg[5];
 	uint8_t reply[2];
+	unsigned retry;
 	int msg_bytes;
 	int reply_bytes;
 	int ret;
@@ -513,14 +514,33 @@ intel_dp_i2c_aux_ch(struct i2c_adapter *adapter, int mode,
 		break;
 	}
 
-	for (;;) {
-	  ret = intel_dp_aux_ch(intel_dp,
-				msg, msg_bytes,
-				reply, reply_bytes);
+	for (retry = 0; retry < 5; retry++) {
+		ret = intel_dp_aux_ch(intel_dp,
+				      msg, msg_bytes,
+				      reply, reply_bytes);
 		if (ret < 0) {
 			DRM_DEBUG_KMS("aux_ch failed %d\n", ret);
 			return ret;
 		}
+
+		switch (reply[0] & AUX_NATIVE_REPLY_MASK) {
+		case AUX_NATIVE_REPLY_ACK:
+			/* I2C-over-AUX Reply field is only valid
+			 * when paired with AUX ACK.
+			 */
+			break;
+		case AUX_NATIVE_REPLY_NACK:
+			DRM_DEBUG_KMS("aux_ch native nack\n");
+			return -EREMOTEIO;
+		case AUX_NATIVE_REPLY_DEFER:
+			udelay(100);
+			continue;
+		default:
+			DRM_ERROR("aux_ch invalid native reply 0x%02x\n",
+				  reply[0]);
+			return -EREMOTEIO;
+		}
+
 		switch (reply[0] & AUX_I2C_REPLY_MASK) {
 		case AUX_I2C_REPLY_ACK:
 			if (mode == MODE_I2C_READ) {
@@ -528,17 +548,20 @@ intel_dp_i2c_aux_ch(struct i2c_adapter *adapter, int mode,
 			}
 			return reply_bytes - 1;
 		case AUX_I2C_REPLY_NACK:
-			DRM_DEBUG_KMS("aux_ch nack\n");
+			DRM_DEBUG_KMS("aux_i2c nack\n");
 			return -EREMOTEIO;
 		case AUX_I2C_REPLY_DEFER:
-			DRM_DEBUG_KMS("aux_ch defer\n");
+			DRM_DEBUG_KMS("aux_i2c defer\n");
 			udelay(100);
 			break;
 		default:
-			DRM_ERROR("aux_ch invalid reply 0x%02x\n", reply[0]);
+			DRM_ERROR("aux_i2c invalid reply 0x%02x\n", reply[0]);
 			return -EREMOTEIO;
 		}
 	}
+
+	DRM_ERROR("too many retries, giving up\n");
+	return -EREMOTEIO;
 }
 
 static int

From 8c0a6bfef165ccdbf5d73afb9dd660107b0c98d5 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Thu, 9 Dec 2010 12:56:37 +0000
Subject: [PATCH 2/5] drm/i915/ringbuffer: Handle wrapping of the autoreported
 HEAD

If the tail advances beyond the autoreport HEAD value, then we need to
fallback to an uncached read of the HEAD register in order to ascertain
the correct amount of remaining space in the ringbuffer.

Reported-by: Fang, Xun <xunx.fang@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=32259
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/intel_ringbuffer.c | 19 ++++++++-----------
 drivers/gpu/drm/i915/intel_ringbuffer.h |  5 +++--
 2 files changed, 11 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 89a65be8a3f36..31cd7e33e8208 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -696,20 +696,17 @@ int intel_wait_ring_buffer(struct drm_device *dev,
 	drm_i915_private_t *dev_priv = dev->dev_private;
 	u32 head;
 
-	head = intel_read_status_page(ring, 4);
-	if (head) {
-		ring->head = head & HEAD_ADDR;
-		ring->space = ring->head - (ring->tail + 8);
-		if (ring->space < 0)
-			ring->space += ring->size;
-		if (ring->space >= n)
-			return 0;
-	}
-
 	trace_i915_ring_wait_begin (dev);
 	end = jiffies + 3 * HZ;
 	do {
-		ring->head = I915_READ_HEAD(ring) & HEAD_ADDR;
+		/* If the reported head position has wrapped or hasn't advanced,
+		 * fallback to the slow and accurate path.
+		 */
+		head = intel_read_status_page(ring, 4);
+		if (head < ring->actual_head)
+			head = I915_READ_HEAD(ring);
+		ring->actual_head = head;
+		ring->head = head & HEAD_ADDR;
 		ring->space = ring->head - (ring->tail + 8);
 		if (ring->space < 0)
 			ring->space += ring->size;
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index 3126c2681983e..d2cd0f1efeedf 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -30,8 +30,9 @@ struct  intel_ring_buffer {
 	struct		drm_device *dev;
 	struct		drm_gem_object *gem_object;
 
-	unsigned int	head;
-	unsigned int	tail;
+	u32		actual_head;
+	u32		head;
+	u32		tail;
 	int		space;
 	struct intel_hw_status_page status_page;
 

From 63abf3edaf42d0b9f278df90fe41c7ed4796b6b1 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Wed, 8 Dec 2010 16:48:21 +0000
Subject: [PATCH 3/5] drm/i915/sdvo: Only use the SDVO pin if it is in the
 valid range

BIOSes. Can't live without them (apparently), definitely can't live with
them.

Reported-by: Ben Gamari <bgamari@gmail.com>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=24312
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/intel_sdvo.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_sdvo.c b/drivers/gpu/drm/i915/intel_sdvo.c
index d97e6cb52d34a..27e63abf2a731 100644
--- a/drivers/gpu/drm/i915/intel_sdvo.c
+++ b/drivers/gpu/drm/i915/intel_sdvo.c
@@ -1908,9 +1908,12 @@ intel_sdvo_select_i2c_bus(struct drm_i915_private *dev_priv,
 		speed = mapping->i2c_speed;
 	}
 
-	sdvo->i2c = &dev_priv->gmbus[pin].adapter;
-	intel_gmbus_set_speed(sdvo->i2c, speed);
-	intel_gmbus_force_bit(sdvo->i2c, true);
+	if (pin < GMBUS_NUM_PORTS) {
+		sdvo->i2c = &dev_priv->gmbus[pin].adapter;
+		intel_gmbus_set_speed(sdvo->i2c, speed);
+		intel_gmbus_force_bit(sdvo->i2c, true);
+	} else
+		sdvo->i2c = &dev_priv->gmbus[GMBUS_PORT_DPB].adapter;
 }
 
 static bool

From 71f4566084eb592fe545f05f7dff41fa9aa42e0b Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Tue, 14 Dec 2010 11:29:23 +0000
Subject: [PATCH 4/5] agp/intel: Fix missed cached memory flags setting in
 i965_write_entry()

This fixes regression from a6963596a13e62f8e65b1cf3403a330ff2db407c,
that missed to set cached memory type in GTT entry.

Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
---
 drivers/char/agp/intel-gtt.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/char/agp/intel-gtt.c b/drivers/char/agp/intel-gtt.c
index 16a2847b7cdbf..29ac6d499fa6a 100644
--- a/drivers/char/agp/intel-gtt.c
+++ b/drivers/char/agp/intel-gtt.c
@@ -1192,12 +1192,19 @@ static void i9xx_chipset_flush(void)
 		writel(1, intel_private.i9xx_flush_page);
 }
 
-static void i965_write_entry(dma_addr_t addr, unsigned int entry,
+static void i965_write_entry(dma_addr_t addr,
+			     unsigned int entry,
 			     unsigned int flags)
 {
+	u32 pte_flags;
+
+	pte_flags = I810_PTE_VALID;
+	if (flags == AGP_USER_CACHED_MEMORY)
+		pte_flags |= I830_PTE_SYSTEM_CACHED;
+
 	/* Shift high bits down */
 	addr |= (addr >> 28) & 0xf0;
-	writel(addr | I810_PTE_VALID, intel_private.gtt + entry);
+	writel(addr | pte_flags, intel_private.gtt + entry);
 }
 
 static bool gen6_check_flags(unsigned int flags)

From 448f53a1ede54eb854d036abf54573281412d650 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Tue, 14 Dec 2010 20:06:20 +0000
Subject: [PATCH 5/5] drm/i915/bios: Reverse order of 100/120 Mhz SSC clocks

Fixes the lack of output on the LVDS panel of the Lenovo U160.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=31596
Reported-and-tested-by: Dirk Gouders <gouders@et.bocholt.fh-gelsenkirchen.de>
Cc: stable@kernel.org
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/intel_bios.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
index b0b1200ed6500..2b2078695d2ac 100644
--- a/drivers/gpu/drm/i915/intel_bios.c
+++ b/drivers/gpu/drm/i915/intel_bios.c
@@ -270,7 +270,7 @@ parse_general_features(struct drm_i915_private *dev_priv,
 					general->ssc_freq ? 66 : 48;
 			else if (IS_GEN5(dev) || IS_GEN6(dev))
 				dev_priv->lvds_ssc_freq =
-					general->ssc_freq ? 100 : 120;
+					general->ssc_freq ? 120 : 100;
 			else
 				dev_priv->lvds_ssc_freq =
 					general->ssc_freq ? 100 : 96;