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

Pull drm fixes from Dave Airlie:
 "Unfortunately this contains no easter eggs, its a bit larger than I'd
  like, but I included a patch that just moves code from one file to
  another and I'd like to avoid merge conflicts with that later, so it
  makes it seem worse than it is,

  Otherwise:
   - radeon: fixes to use new microcode to stabilise some cards, use
     some common displayport code, some runtime pm fixes, pll regression
     fixes
   - i915: fix for some context oopses, a warn in a used path, backlight
     fixes
   - nouveau: regression fix
   - omap: a bunch of fixes"

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux: (51 commits)
  drm: bochs: drop unused struct fields
  drm: bochs: add power management support
  drm: cirrus: add power management support
  drm: Split out drm_probe_helper.c from drm_crtc_helper.c
  drm/plane-helper: Don't fake-implement primary plane disabling
  drm/ast: fix value check in cbr_scan2
  drm/nouveau/bios: fix a bit shift error introduced by 457e77b
  drm/radeon/ci: make sure mc ucode is loaded before checking the size
  drm/radeon/si: make sure mc ucode is loaded before checking the size
  drm/radeon: improve PLL params if we don't match exactly v2
  drm/radeon: memory leak on bo reservation failure. v2
  drm/radeon: fix VCE fence command
  drm/radeon: re-enable mclk dpm on R7 260X asics
  drm/radeon: add support for newer mc ucode on CI (v2)
  drm/radeon: add support for newer mc ucode on SI (v2)
  drm/radeon: apply more strict limits for PLL params v2
  drm/radeon: update CI DPM powertune settings
  drm/radeon: fix runpm handling on APUs (v4)
  drm/radeon: disable mclk dpm on R7 260X
  drm/tegra: Remove gratuitous pad field
  ...

1 files changed, 31 insertions, 13 deletions

diff --git a/drivers/gpu/drm/tegra/dpaux.c b/drivers/gpu/drm/tegra/dpaux.c
index d536ed381fbd..005c19bd92df 100644
--- a/drivers/gpu/drm/tegra/dpaux.c
+++ b/drivers/gpu/drm/tegra/dpaux.c
@@ -99,55 +99,73 @@ static void tegra_dpaux_read_fifo(struct tegra_dpaux *dpaux, u8 *buffer,
 static ssize_t tegra_dpaux_transfer(struct drm_dp_aux *aux,
 				    struct drm_dp_aux_msg *msg)
 {
-	unsigned long value = DPAUX_DP_AUXCTL_TRANSACTREQ;
 	unsigned long timeout = msecs_to_jiffies(250);
 	struct tegra_dpaux *dpaux = to_dpaux(aux);
 	unsigned long status;
 	ssize_t ret = 0;
+	u32 value;
 
-	if (msg->size < 1 || msg->size > 16)
+	/* Tegra has 4x4 byte DP AUX transmit and receive FIFOs. */
+	if (msg->size > 16)
 		return -EINVAL;
 
-	tegra_dpaux_writel(dpaux, msg->address, DPAUX_DP_AUXADDR);
+	/*
+	 * Allow zero-sized messages only for I2C, in which case they specify
+	 * address-only transactions.
+	 */
+	if (msg->size < 1) {
+		switch (msg->request & ~DP_AUX_I2C_MOT) {
+		case DP_AUX_I2C_WRITE:
+		case DP_AUX_I2C_READ:
+			value = DPAUX_DP_AUXCTL_CMD_ADDRESS_ONLY;
+			break;
+
+		default:
+			return -EINVAL;
+		}
+	} else {
+		/* For non-zero-sized messages, set the CMDLEN field. */
+		value = DPAUX_DP_AUXCTL_CMDLEN(msg->size - 1);
+	}
 
 	switch (msg->request & ~DP_AUX_I2C_MOT) {
 	case DP_AUX_I2C_WRITE:
 		if (msg->request & DP_AUX_I2C_MOT)
-			value = DPAUX_DP_AUXCTL_CMD_MOT_WR;
+			value |= DPAUX_DP_AUXCTL_CMD_MOT_WR;
 		else
-			value = DPAUX_DP_AUXCTL_CMD_I2C_WR;
+			value |= DPAUX_DP_AUXCTL_CMD_I2C_WR;
 
 		break;
 
 	case DP_AUX_I2C_READ:
 		if (msg->request & DP_AUX_I2C_MOT)
-			value = DPAUX_DP_AUXCTL_CMD_MOT_RD;
+			value |= DPAUX_DP_AUXCTL_CMD_MOT_RD;
 		else
-			value = DPAUX_DP_AUXCTL_CMD_I2C_RD;
+			value |= DPAUX_DP_AUXCTL_CMD_I2C_RD;
 
 		break;
 
 	case DP_AUX_I2C_STATUS:
 		if (msg->request & DP_AUX_I2C_MOT)
-			value = DPAUX_DP_AUXCTL_CMD_MOT_RQ;
+			value |= DPAUX_DP_AUXCTL_CMD_MOT_RQ;
 		else
-			value = DPAUX_DP_AUXCTL_CMD_I2C_RQ;
+			value |= DPAUX_DP_AUXCTL_CMD_I2C_RQ;
 
 		break;
 
 	case DP_AUX_NATIVE_WRITE:
-		value = DPAUX_DP_AUXCTL_CMD_AUX_WR;
+		value |= DPAUX_DP_AUXCTL_CMD_AUX_WR;
 		break;
 
 	case DP_AUX_NATIVE_READ:
-		value = DPAUX_DP_AUXCTL_CMD_AUX_RD;
+		value |= DPAUX_DP_AUXCTL_CMD_AUX_RD;
 		break;
 
 	default:
 		return -EINVAL;
 	}
 
-	value |= DPAUX_DP_AUXCTL_CMDLEN(msg->size - 1);
+	tegra_dpaux_writel(dpaux, msg->address, DPAUX_DP_AUXADDR);
 	tegra_dpaux_writel(dpaux, value, DPAUX_DP_AUXCTL);
 
 	if ((msg->request & DP_AUX_I2C_READ) == 0) {
@@ -198,7 +216,7 @@ static ssize_t tegra_dpaux_transfer(struct drm_dp_aux *aux,
 		break;
 	}
 
-	if (msg->reply == DP_AUX_NATIVE_REPLY_ACK) {
+	if ((msg->size > 0) && (msg->reply == DP_AUX_NATIVE_REPLY_ACK)) {
 		if (msg->request & DP_AUX_I2C_READ) {
 			size_t count = value & DPAUX_DP_AUXSTAT_REPLY_MASK;