1 files changed, 12 insertions, 1 deletions

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 9770160c0085..60d2006fe15d 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -673,7 +673,18 @@ intel_dp_i2c_aux_ch(struct i2c_adapter *adapter, int mode,
                         DRM_DEBUG_KMS("aux_ch native nack\n");
                         return -EREMOTEIO;
                 case AUX_NATIVE_REPLY_DEFER:
-                        udelay(100);
+                        /*
+                         * For now, just give more slack to branch devices. We
+                         * could check the DPCD for I2C bit rate capabilities,
+                         * and if available, adjust the interval. We could also
+                         * be more careful with DP-to-Legacy adapters where a
+                         * long legacy cable may force very low I2C bit rates.
+                         */
+                        if (intel_dp->dpcd[DP_DOWNSTREAMPORT_PRESENT] &
+                            DP_DWN_STRM_PORT_PRESENT)
+                                usleep_range(500, 600);
+                        else
+                                usleep_range(300, 400);
                         continue;
                 default:
                         DRM_ERROR("aux_ch invalid native reply 0x%02x\n",