1 files changed, 42 insertions, 8 deletions

diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/i2c/aux.c b/drivers/gpu/drm/nouveau/nvkm/subdev/i2c/aux.c
index 4c1f547da463..a11637b0f6cc 100644
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/i2c/aux.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/i2c/aux.c
@@ -40,8 +40,7 @@ nvkm_i2c_aux_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
 		u8 *ptr = msg->buf;
 
 		while (remaining) {
-			u8 cnt = (remaining > 16) ? 16 : remaining;
-			u8 cmd;
+			u8 cnt, retries, cmd;
 
 			if (msg->flags & I2C_M_RD)
 				cmd = 1;
@@ -51,10 +50,19 @@ nvkm_i2c_aux_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
 			if (mcnt || remaining > 16)
 				cmd |= 4; /* MOT */
 
-			ret = aux->func->xfer(aux, true, cmd, msg->addr, ptr, &cnt);
-			if (ret < 0) {
-				nvkm_i2c_aux_release(aux);
-				return ret;
+			for (retries = 0, cnt = 0;
+			     retries < 32 && !cnt;
+			     retries++) {
+				cnt = min_t(u8, remaining, 16);
+				ret = aux->func->xfer(aux, true, cmd,
+						      msg->addr, ptr, &cnt);
+				if (ret < 0)
+					goto out;
+			}
+			if (!cnt) {
+				AUX_TRACE(aux, "no data after 32 retries");
+				ret = -EIO;
+				goto out;
 			}
 
 			ptr += cnt;
@@ -64,8 +72,10 @@ nvkm_i2c_aux_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
 		msg++;
 	}
 
+	ret = num;
+out:
 	nvkm_i2c_aux_release(aux);
-	return num;
+	return ret;
 }
 
 static u32
@@ -105,9 +115,15 @@ nvkm_i2c_aux_acquire(struct nvkm_i2c_aux *aux)
 {
 	struct nvkm_i2c_pad *pad = aux->pad;
 	int ret;
+
 	AUX_TRACE(aux, "acquire");
 	mutex_lock(&aux->mutex);
-	ret = nvkm_i2c_pad_acquire(pad, NVKM_I2C_PAD_AUX);
+
+	if (aux->enabled)
+		ret = nvkm_i2c_pad_acquire(pad, NVKM_I2C_PAD_AUX);
+	else
+		ret = -EIO;
+
 	if (ret)
 		mutex_unlock(&aux->mutex);
 	return ret;
@@ -145,6 +161,24 @@ nvkm_i2c_aux_del(struct nvkm_i2c_aux **paux)
 	}
 }
 
+void
+nvkm_i2c_aux_init(struct nvkm_i2c_aux *aux)
+{
+	AUX_TRACE(aux, "init");
+	mutex_lock(&aux->mutex);
+	aux->enabled = true;
+	mutex_unlock(&aux->mutex);
+}
+
+void
+nvkm_i2c_aux_fini(struct nvkm_i2c_aux *aux)
+{
+	AUX_TRACE(aux, "fini");
+	mutex_lock(&aux->mutex);
+	aux->enabled = false;
+	mutex_unlock(&aux->mutex);
+}
+
 int
 nvkm_i2c_aux_ctor(const struct nvkm_i2c_aux_func *func,
 		  struct nvkm_i2c_pad *pad, int id,