1 files changed, 23 insertions, 23 deletions

diff --git a/drivers/gpu/drm/i915/intel_sdvo.c b/drivers/gpu/drm/i915/intel_sdvo.c
index 45cd37652a37..6a09c1413d60 100644
--- a/drivers/gpu/drm/i915/intel_sdvo.c
+++ b/drivers/gpu/drm/i915/intel_sdvo.c
@@ -473,20 +473,6 @@ static bool intel_sdvo_write_cmd(struct intel_sdvo *intel_sdvo, u8 cmd,
                 return false;
         }
 
-        i = 3;
-        while (status == SDVO_CMD_STATUS_PENDING && i--) {
-                if (!intel_sdvo_read_byte(intel_sdvo,
-                                          SDVO_I2C_CMD_STATUS,
-                                          &status))
-                        return false;
-        }
-        if (status != SDVO_CMD_STATUS_SUCCESS) {
-                DRM_DEBUG_KMS("command returns response %s [%d]\n",
-                              status <= SDVO_CMD_STATUS_SCALING_NOT_SUPP ? cmd_status_names[status] : "???",
-                              status);
-                return false;
-        }
-
         return true;
 }
 
@@ -497,6 +483,8 @@ static bool intel_sdvo_read_response(struct intel_sdvo *intel_sdvo,
         u8 status;
         int i;
 
+        DRM_DEBUG_KMS("%s: R: ", SDVO_NAME(intel_sdvo));
+
         /*
          * The documentation states that all commands will be
          * processed within 15µs, and that we need only poll
@@ -505,14 +493,19 @@ static bool intel_sdvo_read_response(struct intel_sdvo *intel_sdvo,
          *
          * Check 5 times in case the hardware failed to read the docs.
          */
-        do {
+        if (!intel_sdvo_read_byte(intel_sdvo,
+                                  SDVO_I2C_CMD_STATUS,
+                                  &status))
+                goto log_fail;
+
+        while (status == SDVO_CMD_STATUS_PENDING && retry--) {
+                udelay(15);
                 if (!intel_sdvo_read_byte(intel_sdvo,
                                           SDVO_I2C_CMD_STATUS,
                                           &status))
-                        return false;
-        } while (status == SDVO_CMD_STATUS_PENDING && --retry);
+                        goto log_fail;
+        }
 
-        DRM_DEBUG_KMS("%s: R: ", SDVO_NAME(intel_sdvo));
         if (status <= SDVO_CMD_STATUS_SCALING_NOT_SUPP)
                 DRM_LOG_KMS("(%s)", cmd_status_names[status]);
         else
@@ -533,7 +526,7 @@ static bool intel_sdvo_read_response(struct intel_sdvo *intel_sdvo,
         return true;
 
 log_fail:
-        DRM_LOG_KMS("\n");
+        DRM_LOG_KMS("... failed\n");
         return false;
 }
 
@@ -550,6 +543,7 @@ static int intel_sdvo_get_pixel_multiplier(struct drm_display_mode *mode)
 static bool intel_sdvo_set_control_bus_switch(struct intel_sdvo *intel_sdvo,
                                               u8 ddc_bus)
 {
+        /* This must be the immediately preceding write before the i2c xfer */
         return intel_sdvo_write_cmd(intel_sdvo,
                                     SDVO_CMD_SET_CONTROL_BUS_SWITCH,
                                     &ddc_bus, 1);
@@ -557,7 +551,10 @@ static bool intel_sdvo_set_control_bus_switch(struct intel_sdvo *intel_sdvo,
 
 static bool intel_sdvo_set_value(struct intel_sdvo *intel_sdvo, u8 cmd, const void *data, int len)
 {
-        return intel_sdvo_write_cmd(intel_sdvo, cmd, data, len);
+        if (!intel_sdvo_write_cmd(intel_sdvo, cmd, data, len))
+                return false;
+
+        return intel_sdvo_read_response(intel_sdvo, NULL, 0);
 }
 
 static bool
@@ -859,18 +856,21 @@ static bool intel_sdvo_set_avi_infoframe(struct intel_sdvo *intel_sdvo)
 
         intel_dip_infoframe_csum(&avi_if);
 
-        if (!intel_sdvo_write_cmd(intel_sdvo, SDVO_CMD_SET_HBUF_INDEX,
+        if (!intel_sdvo_set_value(intel_sdvo,
+                                  SDVO_CMD_SET_HBUF_INDEX,
                                   set_buf_index, 2))
                 return false;
 
         for (i = 0; i < sizeof(avi_if); i += 8) {
-                if (!intel_sdvo_write_cmd(intel_sdvo, SDVO_CMD_SET_HBUF_DATA,
+                if (!intel_sdvo_set_value(intel_sdvo,
+                                          SDVO_CMD_SET_HBUF_DATA,
                                           data, 8))
                         return false;
                 data++;
         }
 
-        return intel_sdvo_write_cmd(intel_sdvo, SDVO_CMD_SET_HBUF_TXRATE,
+        return intel_sdvo_set_value(intel_sdvo,
+                                    SDVO_CMD_SET_HBUF_TXRATE,
                                     &tx_rate, 1);
 }