From c807b30d2588dd3c74db1f690a0e9e724dd332da Mon Sep 17 00:00:00 2001 From: Kalle Valo Date: Mon, 6 Feb 2012 08:23:40 +0200 Subject: [PATCH] ath6kl: add blocking debugfs file for retrieving firmware logs When debugging firmware issues it's not always enough to get the latest firmware logs, sometimes we need to get logs from a longer period. To make this possible, add a debugfs file named fwlog_block. When reading from this file ath6kl will send firmware logs whenever available and otherwise it will block and wait for new logs. Signed-off-by: Kalle Valo --- drivers/net/wireless/ath/ath6kl/core.h | 3 + drivers/net/wireless/ath/ath6kl/debug.c | 104 +++++++++++++++++++++++- 2 files changed, 106 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/ath/ath6kl/core.h b/drivers/net/wireless/ath/ath6kl/core.h index 9a58214135b9..4ff06a326785 100644 --- a/drivers/net/wireless/ath/ath6kl/core.h +++ b/drivers/net/wireless/ath/ath6kl/core.h @@ -653,6 +653,9 @@ struct ath6kl { #ifdef CONFIG_ATH6KL_DEBUG struct { struct sk_buff_head fwlog_queue; + struct completion fwlog_completion; + bool fwlog_open; + u32 fwlog_mask; unsigned int dbgfs_diag_reg; diff --git a/drivers/net/wireless/ath/ath6kl/debug.c b/drivers/net/wireless/ath/ath6kl/debug.c index 98b5f15f622e..ec32ff692163 100644 --- a/drivers/net/wireless/ath/ath6kl/debug.c +++ b/drivers/net/wireless/ath/ath6kl/debug.c @@ -290,6 +290,7 @@ void ath6kl_debug_fwlog_event(struct ath6kl *ar, const void *buf, size_t len) spin_lock(&ar->debug.fwlog_queue.lock); __skb_queue_tail(&ar->debug.fwlog_queue, skb); + complete(&ar->debug.fwlog_completion); /* drop oldest entries */ while (skb_queue_len(&ar->debug.fwlog_queue) > @@ -303,6 +304,28 @@ void ath6kl_debug_fwlog_event(struct ath6kl *ar, const void *buf, size_t len) return; } +static int ath6kl_fwlog_open(struct inode *inode, struct file *file) +{ + struct ath6kl *ar = inode->i_private; + + if (ar->debug.fwlog_open) + return -EBUSY; + + ar->debug.fwlog_open = true; + + file->private_data = inode->i_private; + return 0; +} + +static int ath6kl_fwlog_release(struct inode *inode, struct file *file) +{ + struct ath6kl *ar = inode->i_private; + + ar->debug.fwlog_open = false; + + return 0; +} + static ssize_t ath6kl_fwlog_read(struct file *file, char __user *user_buf, size_t count, loff_t *ppos) { @@ -347,12 +370,87 @@ static ssize_t ath6kl_fwlog_read(struct file *file, char __user *user_buf, } static const struct file_operations fops_fwlog = { - .open = ath6kl_debugfs_open, + .open = ath6kl_fwlog_open, + .release = ath6kl_fwlog_release, .read = ath6kl_fwlog_read, .owner = THIS_MODULE, .llseek = default_llseek, }; +static ssize_t ath6kl_fwlog_block_read(struct file *file, + char __user *user_buf, + size_t count, + loff_t *ppos) +{ + struct ath6kl *ar = file->private_data; + struct sk_buff *skb; + ssize_t ret_cnt; + size_t len = 0, not_copied; + char *buf; + int ret; + + buf = vmalloc(count); + if (!buf) + return -ENOMEM; + + spin_lock(&ar->debug.fwlog_queue.lock); + + if (skb_queue_len(&ar->debug.fwlog_queue) == 0) { + /* we must init under queue lock */ + init_completion(&ar->debug.fwlog_completion); + + spin_unlock(&ar->debug.fwlog_queue.lock); + + ret = wait_for_completion_interruptible( + &ar->debug.fwlog_completion); + if (ret == -ERESTARTSYS) + return ret; + + spin_lock(&ar->debug.fwlog_queue.lock); + } + + while ((skb = __skb_dequeue(&ar->debug.fwlog_queue))) { + if (skb->len > count - len) { + /* not enough space, put skb back and leave */ + __skb_queue_head(&ar->debug.fwlog_queue, skb); + break; + } + + + memcpy(buf + len, skb->data, skb->len); + len += skb->len; + + kfree_skb(skb); + } + + spin_unlock(&ar->debug.fwlog_queue.lock); + + /* FIXME: what to do if len == 0? */ + + not_copied = copy_to_user(user_buf, buf, len); + if (not_copied != 0) { + ret_cnt = -EFAULT; + goto out; + } + + *ppos = *ppos + len; + + ret_cnt = len; + +out: + vfree(buf); + + return ret_cnt; +} + +static const struct file_operations fops_fwlog_block = { + .open = ath6kl_fwlog_open, + .release = ath6kl_fwlog_release, + .read = ath6kl_fwlog_block_read, + .owner = THIS_MODULE, + .llseek = default_llseek, +}; + static ssize_t ath6kl_fwlog_mask_read(struct file *file, char __user *user_buf, size_t count, loff_t *ppos) { @@ -1623,6 +1721,7 @@ static const struct file_operations fops_power_params = { int ath6kl_debug_init(struct ath6kl *ar) { skb_queue_head_init(&ar->debug.fwlog_queue); + init_completion(&ar->debug.fwlog_completion); /* * Actually we are lying here but don't know how to read the mask @@ -1647,6 +1746,9 @@ int ath6kl_debug_init(struct ath6kl *ar) debugfs_create_file("fwlog", S_IRUSR, ar->debugfs_phy, ar, &fops_fwlog); + debugfs_create_file("fwlog_block", S_IRUSR, ar->debugfs_phy, ar, + &fops_fwlog_block); + debugfs_create_file("fwlog_mask", S_IRUSR | S_IWUSR, ar->debugfs_phy, ar, &fops_fwlog_mask); -- GitLab