Hi Archie,
> Thanks for the fantastic patch! My comments inline.
>
>>
>> Signed-off-by: Marcel Holtmann <marcel@xxxxxxxxxxxx>
>> ---
>> include/net/bluetooth/bluetooth.h | 10 ++++-
>> net/bluetooth/Kconfig | 4 ++
>> net/bluetooth/af_bluetooth.c | 2 +
>> net/bluetooth/lib.c | 69 +++++++++++++++++++++++++++++++
>> 4 files changed, 84 insertions(+), 1 deletion(-)
>>
>> diff --git a/include/net/bluetooth/bluetooth.h b/include/net/bluetooth/bluetooth.h
>> index e42bb8e03c09..d32d1f401efb 100644
>> --- a/include/net/bluetooth/bluetooth.h
>> +++ b/include/net/bluetooth/bluetooth.h
>> @@ -129,6 +129,8 @@ void bt_warn(const char *fmt, ...);
>> __printf(1, 2)
>> void bt_err(const char *fmt, ...);
>> __printf(1, 2)
>> +void bt_dbg(const char *fmt, ...);
>> +__printf(1, 2)
>> void bt_warn_ratelimited(const char *fmt, ...);
>> __printf(1, 2)
>> void bt_err_ratelimited(const char *fmt, ...);
>> @@ -136,7 +138,11 @@ void bt_err_ratelimited(const char *fmt, ...);
>> #define BT_INFO(fmt, ...) bt_info(fmt "\n", ##__VA_ARGS__)
>> #define BT_WARN(fmt, ...) bt_warn(fmt "\n", ##__VA_ARGS__)
>> #define BT_ERR(fmt, ...) bt_err(fmt "\n", ##__VA_ARGS__)
>> -#define BT_DBG(fmt, ...) pr_debug(fmt "\n", ##__VA_ARGS__)
>> +#if IS_ENABLED(CONFIG_BT_DEBUGFS_OPTION)
>> +#define BT_DBG(fmt, ...) bt_dbg(fmt "\n", ##__VA_ARGS__)
>> +#else
>> +#define BT_DBG(fmt, ...) pr_debug(mt "\n", ##__VA_ARGS__)
>
> Should be fmt instead of mt.
Indeed.
>
>> +#endif
>>
>> #define bt_dev_info(hdev, fmt, ...) \
>> BT_INFO("%s: " fmt, (hdev)->name, ##__VA_ARGS__)
>> @@ -393,6 +399,8 @@ void bt_procfs_cleanup(struct net *net, const char *name);
>>
>> extern struct dentry *bt_debugfs;
>>
>> +void bt_lib_debugfs_init(void);
>> +
>> int l2cap_init(void);
>> void l2cap_exit(void);
>>
>> diff --git a/net/bluetooth/Kconfig b/net/bluetooth/Kconfig
>> index 165148c7c4ce..64833640bf3d 100644
>> --- a/net/bluetooth/Kconfig
>> +++ b/net/bluetooth/Kconfig
>> @@ -128,4 +128,8 @@ config BT_DEBUGFS
>> Provide extensive information about internal Bluetooth states
>> in debugfs.
>>
>> +config BT_DEBUGFS_OPTION
>> + bool
>> + default y if BT_DEBUGFS && !DYNAMIC_DEBUG
>
> If I understand it correctly, setting BT_DEBUGFS_OPTION to true
> will cause all of the BT_DBG logs to be loaded into the resulting
> build. Prior to the introduction of this config setting, the logs by
> default are discarded from the build. Therefore, by introducing this
> option, there will be an increase in the size of the build.
>
> Shouldn't this option defaults to false instead?
It defaults to y only if you a) selected BT_DEBUGFS and b) have disabled DYNAMIC_DEBUG. Otherwise it is off and defaults back to using pr_debug. Which is in case of disabled DYNAMIC_DEBUG results in disabled debug statement.
So it is not worth than with dynamic debug. We could tweak the bt_dbg part a bit to reduce the overhead, but it is not as bad. However what we can add is an extra comment in the BT_DEBUGFS help text to mention that case with DYNAMIC_DEBUG disabled.
>> +
>> source "drivers/bluetooth/Kconfig"
>> diff --git a/net/bluetooth/af_bluetooth.c b/net/bluetooth/af_bluetooth.c
>> index 3fd124927d4d..fa0cd665f32a 100644
>> --- a/net/bluetooth/af_bluetooth.c
>> +++ b/net/bluetooth/af_bluetooth.c
>> @@ -731,6 +731,8 @@ static int __init bt_init(void)
>>
>> bt_debugfs = debugfs_create_dir("bluetooth", NULL);
>>
>> + bt_lib_debugfs_init();
>> +
>> bt_leds_init();
>>
>> err = bt_sysfs_init();
>> diff --git a/net/bluetooth/lib.c b/net/bluetooth/lib.c
>> index c09e0a3a0ed9..28cfc3fd8fbe 100644
>> --- a/net/bluetooth/lib.c
>> +++ b/net/bluetooth/lib.c
>> @@ -27,6 +27,7 @@
>> #define pr_fmt(fmt) "Bluetooth: " fmt
>>
>> #include <linux/export.h>
>> +#include <linux/debugfs.h>
>>
>> #include <net/bluetooth/bluetooth.h>
>>
>> @@ -135,6 +136,55 @@ int bt_to_errno(__u16 code)
>> }
>> EXPORT_SYMBOL(bt_to_errno);
>>
>> +#ifdef CONFIG_BT_DEBUGFS_OPTION
>> +static bool debug_enable;
>> +
>> +static ssize_t debug_enable_read(struct file *file, char __user *user_buf,
>> + size_t count, loff_t *ppos)
>> +{
>> + char buf[3];
>> +
>> + buf[0] = debug_enable ? 'Y': 'N';
>> + buf[1] = '\n';
>> + buf[2] = '\0';
>> + return simple_read_from_buffer(user_buf, count, ppos, buf, 2);
>> +}
>> +
>> +static ssize_t debug_enable_write(struct file *file,
>> + const char __user *user_buf,
>> + size_t count, loff_t *ppos)
>> +{
>> + bool enable;
>> + int err;
>> +
>> + err = kstrtobool_from_user(user_buf, count, &enable);
>> + if (err)
>> + return err;
>> +
>> + if (enable == debug_enable)
>> + return -EALREADY;
>> +
>> + debug_enable = enable;
>> +
>> + return count;
>> +}
>> +
>> +static const struct file_operations debug_enable_fops = {
>> + .open = simple_open,
>> + .read = debug_enable_read,
>> + .write = debug_enable_write,
>> + .llseek = default_llseek,
>> +};
>> +
>> +void bt_lib_debugfs_init(void)
>> +{
>> + debugfs_create_file("debug_enable", 0644, bt_debugfs, NULL,
>> + &debug_enable_fops);
>> +}
>> +#else
>> +void bt_lib_debugfs_init(void);
>
> Should be the empty function
> bt_lib_debugfs_init(void)
> {
> }
>
Correct. I screwed this up.
Regards
Marcel
