static int si2157_cmd_execute(struct si2157 *s, struct si2157_cmd *cmd)
 {
        int ret;
-       u8 buf[1];
        unsigned long timeout;
 
        mutex_lock(&s->i2c_mutex);
 
-       if (cmd->len) {
+       if (cmd->wlen) {
                /* write cmd and args for firmware */
-               ret = i2c_master_send(s->client, cmd->args, cmd->len);
+               ret = i2c_master_send(s->client, cmd->args, cmd->wlen);
                if (ret < 0) {
                        goto err_mutex_unlock;
-               } else if (ret != cmd->len) {
+               } else if (ret != cmd->wlen) {
                        ret = -EREMOTEIO;
                        goto err_mutex_unlock;
                }
        }
 
-       /* wait cmd execution terminate */
-       #define TIMEOUT 80
-       timeout = jiffies + msecs_to_jiffies(TIMEOUT);
-       while (!time_after(jiffies, timeout)) {
-               ret = i2c_master_recv(s->client, buf, 1);
-               if (ret < 0) {
-                       goto err_mutex_unlock;
-               } else if (ret != 1) {
-                       ret = -EREMOTEIO;
-                       goto err_mutex_unlock;
+       if (cmd->rlen) {
+               /* wait cmd execution terminate */
+               #define TIMEOUT 80
+               timeout = jiffies + msecs_to_jiffies(TIMEOUT);
+               while (!time_after(jiffies, timeout)) {
+                       ret = i2c_master_recv(s->client, cmd->args, cmd->rlen);
+                       if (ret < 0) {
+                               goto err_mutex_unlock;
+                       } else if (ret != cmd->rlen) {
+                               ret = -EREMOTEIO;
+                               goto err_mutex_unlock;
+                       }
+
+                       /* firmware ready? */
+                       if ((cmd->args[0] >> 7) & 0x01)
+                               break;
                }
 
-               /* firmware ready? */
-               if ((buf[0] >> 7) & 0x01)
-                       break;
-       }
+               dev_dbg(&s->client->dev, "%s: cmd execution took %d ms\n",
+                               __func__,
+                               jiffies_to_msecs(jiffies) -
+                               (jiffies_to_msecs(timeout) - TIMEOUT));
 
-       dev_dbg(&s->client->dev, "%s: cmd execution took %d ms\n", __func__,
-                       jiffies_to_msecs(jiffies) -
-                       (jiffies_to_msecs(timeout) - TIMEOUT));
-
-       if (!(buf[0] >> 7) & 0x01) {
-               ret = -ETIMEDOUT;
-               goto err_mutex_unlock;
-       } else {
-               ret = 0;
+               if (!((cmd->args[0] >> 7) & 0x01)) {
+                       ret = -ETIMEDOUT;
+                       goto err_mutex_unlock;
+               }
        }
 
+       ret = 0;
+
 err_mutex_unlock:
        mutex_unlock(&s->i2c_mutex);
        if (ret)
        s->active = false;
 
        memcpy(cmd.args, "\x13", 1);
-       cmd.len = 1;
+       cmd.wlen = 1;
+       cmd.rlen = 0;
        ret = si2157_cmd_execute(s, &cmd);
        if (ret)
                goto err;
        cmd.args[12] = 0x00;
        cmd.args[13] = 0x00;
        cmd.args[14] = 0x01;
-       cmd.len = 15;
+       cmd.wlen = 15;
+       cmd.rlen = 1;
        ret = si2157_cmd_execute(s, &cmd);
        if (ret)
                goto err;
 
        cmd.args[0] = 0x02;
-       cmd.len = 1;
+       cmd.wlen = 1;
+       cmd.rlen = 13;
        ret = si2157_cmd_execute(s, &cmd);
        if (ret)
                goto err;
 
        cmd.args[0] = 0x01;
        cmd.args[1] = 0x01;
-       cmd.len = 2;
+       cmd.wlen = 2;
+       cmd.rlen = 1;
        ret = si2157_cmd_execute(s, &cmd);
        if (ret)
                goto err;
        cmd.args[5] = (c->frequency >>  8) & 0xff;
        cmd.args[6] = (c->frequency >> 16) & 0xff;
        cmd.args[7] = (c->frequency >> 24) & 0xff;
-       cmd.len = 8;
+       cmd.wlen = 8;
+       cmd.rlen = 1;
        ret = si2157_cmd_execute(s, &cmd);
        if (ret)
                goto err;
        mutex_init(&s->i2c_mutex);
 
        /* check if the tuner is there */
-       cmd.len = 0;
+       cmd.wlen = 0;
+       cmd.rlen = 1;
        ret = si2157_cmd_execute(s, &cmd);
        if (ret)
                goto err;