Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux

Pull drm updates from Dave Airlie:
 "I Was Almost Tempted To Capitalise Every Word, but then I decided I
  couldn't read it myself!

  I've also got one pull request for the sti driver outstanding.  It
  relied on a commit in Greg's tree and I didn't find out in time, that
  commit is in your tree now so I might send that along once this is
  merged.

  I also had the accidental misfortune to have access to a Skylake on my
  desk for a few days, and I've had to encourage Intel to try harder,
  which seems to be happening now.

  Here is the main drm-next pull request for 4.4.

  Highlights:

  New driver:
        vc4 driver for the Rasberry Pi VPU.
        (From Eric Anholt at Broadcom.)

  Core:
        Atomic fbdev support
        Atomic helpers for runtime pm
        dp/aux i2c STATUS_UPDATE handling
        struct_mutex usage cleanups.
        Generic of probing support.

  Documentation:
        Kerneldoc for VGA switcheroo code.
        Rename to gpu instead of drm to reflect scope.

  i915:
        Skylake GuC firmware fixes
        HPD A support
        VBT backlight fallbacks
        Fastboot by default for some systems
        FBC work
        BXT/SKL workarounds
        Skylake deeper sleep state fixes

  amdgpu:
        Enable GPU scheduler by default
        New atombios opcodes
        GPUVM debugging options
        Stoney support.
        Fencing cleanups.

  radeon:
        More efficient CS checking

  nouveau:
        gk20a instance memory handling improvements.
        Improved PGOB detection and GK107 support
        Kepler GDDR5 PLL statbility improvement
        G8x/GT2xx reclock improvements
        new userspace API compatiblity fixes.

  virtio-gpu:
        Add 3D support - qemu 2.5 has it merged for it's gtk backend.

  msm:
        Initial msm88896 (snapdragon 8200)

  exynos:
        HDMI cleanups
        Enable mixer driver byt default
        Add DECON-TV support

  vmwgfx:
        Move to using memremap + fixes.

  rcar-du:
        Add support for R8A7793/4 DU

  armada:
        Remove support for non-component mode
        Improved plane handling
        Power savings while in DPMS off.

  tda998x:
        Remove unused slave encoder support
        Use more HDMI helpers
        Fix EDID read handling

  dwhdmi:
        Interlace video mode support for ipu-v3/dw_hdmi
        Hotplug state fixes
        Audio driver integration

  imx:
        More color formats support.

  tegra:
        Minor fixes/improvements"

[ Merge fixup: remove unused variable 'dev' that had all uses removed in
  commit 4e270f088011: "drm/gem: Drop struct_mutex requirement from
  drm_gem_mmap_obj" ]

* 'drm-next' of git://people.freedesktop.org/~airlied/linux: (764 commits)
  drm/vmwgfx: Relax irq locking somewhat
  drm/vmwgfx: Properly flush cursor updates and page-flips
  drm/i915/skl: disable display side power well support for now
  drm/i915: Extend DSL readout fix to BDW and SKL.
  drm/i915: Do graphics device reset under forcewake
  drm/i915: Skip fence installation for objects with rotated views (v4)
  vga_switcheroo: Drop client power state VGA_SWITCHEROO_INIT
  drm/amdgpu: group together common fence implementation
  drm/amdgpu: remove AMDGPU_FENCE_OWNER_MOVE
  drm/amdgpu: remove now unused fence functions
  drm/amdgpu: fix fence fallback check
  drm/amdgpu: fix stoping the scheduler timeout
  drm/amdgpu: cleanup on error in amdgpu_cs_ioctl()
  drm/i915: Fix locking around GuC firmware load
  drm/amdgpu: update Fiji's Golden setting
  drm/amdgpu: update Fiji's rev id
  drm/amdgpu: extract common code in vi_common_early_init
  drm/amd/scheduler: don't oops on failure to load
  drm/amdgpu: don't oops on failure to load (v2)
  drm/amdgpu: don't VT switch on suspend
  ...

1 files changed, 40 insertions, 4 deletions

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index 291734e87fca..9535c5b60387 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -424,6 +424,19 @@ static u32 drm_dp_i2c_functionality(struct i2c_adapter *adapter)
 	       I2C_FUNC_10BIT_ADDR;
 }
 
+static void drm_dp_i2c_msg_write_status_update(struct drm_dp_aux_msg *msg)
+{
+	/*
+	 * In case of i2c defer or short i2c ack reply to a write,
+	 * we need to switch to WRITE_STATUS_UPDATE to drain the
+	 * rest of the message
+	 */
+	if ((msg->request & ~DP_AUX_I2C_MOT) == DP_AUX_I2C_WRITE) {
+		msg->request &= DP_AUX_I2C_MOT;
+		msg->request |= DP_AUX_I2C_WRITE_STATUS_UPDATE;
+	}
+}
+
 #define AUX_PRECHARGE_LEN 10 /* 10 to 16 */
 #define AUX_SYNC_LEN (16 + 4) /* preamble + AUX_SYNC_END */
 #define AUX_STOP_LEN 4
@@ -579,6 +592,8 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
 			 * Both native ACK and I2C ACK replies received. We
 			 * can assume the transfer was successful.
 			 */
+			if (ret != msg->size)
+				drm_dp_i2c_msg_write_status_update(msg);
 			return ret;
 
 		case DP_AUX_I2C_REPLY_NACK:
@@ -596,6 +611,8 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
 			if (defer_i2c < 7)
 				defer_i2c++;
 			usleep_range(AUX_RETRY_INTERVAL, AUX_RETRY_INTERVAL + 100);
+			drm_dp_i2c_msg_write_status_update(msg);
+
 			continue;
 
 		default:
@@ -608,6 +625,14 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
 	return -EREMOTEIO;
 }
 
+static void drm_dp_i2c_msg_set_request(struct drm_dp_aux_msg *msg,
+				       const struct i2c_msg *i2c_msg)
+{
+	msg->request = (i2c_msg->flags & I2C_M_RD) ?
+		DP_AUX_I2C_READ : DP_AUX_I2C_WRITE;
+	msg->request |= DP_AUX_I2C_MOT;
+}
+
 /*
  * Keep retrying drm_dp_i2c_do_msg until all data has been transferred.
  *
@@ -661,10 +686,7 @@ static int drm_dp_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
 
 	for (i = 0; i < num; i++) {
 		msg.address = msgs[i].addr;
-		msg.request = (msgs[i].flags & I2C_M_RD) ?
-			DP_AUX_I2C_READ :
-			DP_AUX_I2C_WRITE;
-		msg.request |= DP_AUX_I2C_MOT;
+		drm_dp_i2c_msg_set_request(&msg, &msgs[i]);
 		/* Send a bare address packet to start the transaction.
 		 * Zero sized messages specify an address only (bare
 		 * address) transaction.
@@ -672,6 +694,13 @@ static int drm_dp_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
 		msg.buffer = NULL;
 		msg.size = 0;
 		err = drm_dp_i2c_do_msg(aux, &msg);
+
+		/*
+		 * Reset msg.request in case in case it got
+		 * changed into a WRITE_STATUS_UPDATE.
+		 */
+		drm_dp_i2c_msg_set_request(&msg, &msgs[i]);
+
 		if (err < 0)
 			break;
 		/* We want each transaction to be as large as possible, but
@@ -684,6 +713,13 @@ static int drm_dp_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
 			msg.size = min(transfer_size, msgs[i].len - j);
 
 			err = drm_dp_i2c_drain_msg(aux, &msg);
+
+			/*
+			 * Reset msg.request in case in case it got
+			 * changed into a WRITE_STATUS_UPDATE.
+			 */
+			drm_dp_i2c_msg_set_request(&msg, &msgs[i]);
+
 			if (err < 0)
 				break;
 			transfer_size = err;