ath10k: request fw_stats once on open

Stats were requested and processed for each read
call. This caused inconsistent readings.

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

diff --git a/drivers/net/wireless/ath/ath10k/debug.c b/drivers/net/wireless/ath/ath10k/debug.c
index 9e85533..1ca1fed 100644 (file)
--- a/drivers/net/wireless/ath/ath10k/debug.c
+++ b/drivers/net/wireless/ath/ath10k/debug.c
@@ -257,38 +257,35 @@ unlock:
        spin_unlock_bh(&ar->data_lock);
 }
 
-static ssize_t ath10k_fw_stats_read(struct file *file, char __user *user_buf,
-                                   size_t count, loff_t *ppos)
+static int ath10k_fw_stats_request(struct ath10k *ar)
 {
-       struct ath10k *ar = file->private_data;
-       struct ath10k_fw_stats *fw_stats;
-       char *buf = NULL;
-       unsigned int len = 0, buf_len = 8000;
-       ssize_t ret_cnt = 0;
-       long left;
-       int i;
        int ret;
 
-       fw_stats = &ar->debug.fw_stats;
-
-       mutex_lock(&ar->conf_mutex);
-
-       if (ar->state != ATH10K_STATE_ON)
-               goto exit;
-
-       buf = kzalloc(buf_len, GFP_KERNEL);
-       if (!buf)
-               goto exit;
+       lockdep_assert_held(&ar->conf_mutex);
 
        ret = ath10k_wmi_request_stats(ar, WMI_REQUEST_PEER_STAT);
        if (ret) {
-               ath10k_warn(ar, "could not request stats (%d)\n", ret);
-               goto exit;
+               ath10k_warn(ar, "failed to fw stat request command: %d\n", ret);
+               return ret;
        }
 
-       left = wait_for_completion_timeout(&ar->debug.fw_stats_complete, 1*HZ);
-       if (left <= 0)
-               goto exit;
+       ret = wait_for_completion_timeout(&ar->debug.fw_stats_complete, 1*HZ);
+       if (ret <= 0)
+               return -ETIMEDOUT;
+
+       return 0;
+}
+
+/* FIXME: How to calculate the buffer size sanely? */
+#define ATH10K_FW_STATS_BUF_SIZE (1024*1024)
+
+static void ath10k_fw_stats_fill(struct ath10k *ar,
+                                struct ath10k_fw_stats *fw_stats,
+                                char *buf)
+{
+       unsigned int len = 0;
+       unsigned int buf_len = ATH10K_FW_STATS_BUF_SIZE;
+       int i;
 
        spin_lock_bh(&ar->data_lock);
        len += scnprintf(buf + len, buf_len - len, "\n");
@@ -433,20 +430,71 @@ static ssize_t ath10k_fw_stats_read(struct file *file, char __user *user_buf,
        }
        spin_unlock_bh(&ar->data_lock);
 
-       if (len > buf_len)
-               len = buf_len;
+       if (len >= buf_len)
+               buf[len - 1] = 0;
+       else
+               buf[len] = 0;
+}
 
-       ret_cnt = simple_read_from_buffer(user_buf, count, ppos, buf, len);
+static int ath10k_fw_stats_open(struct inode *inode, struct file *file)
+{
+       struct ath10k *ar = inode->i_private;
+       void *buf = NULL;
+       int ret;
+
+       mutex_lock(&ar->conf_mutex);
+
+       if (ar->state != ATH10K_STATE_ON) {
+               ret = -ENETDOWN;
+               goto err_unlock;
+       }
+
+       buf = vmalloc(ATH10K_FW_STATS_BUF_SIZE);
+       if (!buf) {
+               ret = -ENOMEM;
+               goto err_unlock;
+       }
+
+       ret = ath10k_fw_stats_request(ar);
+       if (ret) {
+               ath10k_warn(ar, "failed to request fw stats: %d\n", ret);
+               goto err_free;
+       }
+
+       ath10k_fw_stats_fill(ar, &ar->debug.fw_stats, buf);
+       file->private_data = buf;
 
-exit:
        mutex_unlock(&ar->conf_mutex);
-       kfree(buf);
-       return ret_cnt;
+       return 0;
+
+err_free:
+       vfree(buf);
+
+err_unlock:
+       mutex_unlock(&ar->conf_mutex);
+       return ret;
+}
+
+static int ath10k_fw_stats_release(struct inode *inode, struct file *file)
+{
+       vfree(file->private_data);
+
+       return 0;
+}
+
+static ssize_t ath10k_fw_stats_read(struct file *file, char __user *user_buf,
+                                   size_t count, loff_t *ppos)
+{
+       const char *buf = file->private_data;
+       unsigned int len = strlen(buf);
+
+       return simple_read_from_buffer(user_buf, count, ppos, buf, len);
 }
 
 static const struct file_operations fops_fw_stats = {
+       .open = ath10k_fw_stats_open,
+       .release = ath10k_fw_stats_release,
        .read = ath10k_fw_stats_read,
-       .open = simple_open,
        .owner = THIS_MODULE,
        .llseek = default_llseek,
 };