Re: [PATCH 1/4] New netlink command for TID specific configuration

On 2018-11-06 15:46, Sergey Matyukevich wrote:

Hello Tamizh,

quoted

Co-Developed-by: Tamizh Chelvam <redacted>
Signed-off-by: Vasanthakumar Thiagarajan <redacted>
Signed-off-by: Tamizh chelvam <redacted>
---
 include/net/cfg80211.h       |   14 +++++++
 include/uapi/linux/nl80211.h |   69 +++++++++++++++++++++++++++++++++
 net/wireless/nl80211.c       |   86 
++++++++++++++++++++++++++++++++++++++++++
 net/wireless/rdev-ops.h      |   15 ++++++++
 net/wireless/trace.h         |   27 +++++++++++++
 5 files changed, 211 insertions(+)

...

quoted

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 5801d76..dd024da 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h

...

quoted

 /**

@@ -4035,6 +4044,9 @@ struct wiphy_iftype_ext_capab {
  * @txq_limit: configuration of internal TX queue frame limit
  * @txq_memory_limit: configuration internal TX queue memory limit
  * @txq_quantum: configuration of internal TX queue scheduler quantum
+ *
+ * @max_data_retry_count: Maximum limit can be configured as retry 

count
+ *     for a TID.
  */
 struct wiphy {
        /* assign these fields before you register the wiphy */

@@ -4171,6 +4183,8 @@ struct wiphy {
        u32 txq_memory_limit;
        u32 txq_quantum;

+       u8 max_data_retry_count;
+
        char priv[0] __aligned(NETDEV_ALIGN);
 };

Could you please clarify why do you define max_data_retry_count instead 
of
making use of existing wiphy params: retry_short (dot11ShortRetryLimit)
and retry_long (dot11LongRetryLimit) ?

max_data_retry_count added to validate the max limit for the retry count 
supported by the driver.
existing wiphy parames: retry_short and retry_long can be modified 
through user command.
So, I've added this param for validation purpose. Correct me If I'm 
wrong.

quoted

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index d744388..d386ad7 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c

...

quoted

+static int nl80211_set_tid_config(struct sk_buff *skb,
+                                 struct genl_info *info)
+{
+       struct cfg80211_registered_device *rdev = info->user_ptr[0];
+       struct nlattr *attrs[NL80211_ATTR_TID_MAX + 1];
+       struct nlattr *tid;
+       struct net_device *dev = info->user_ptr[1];
+       const char *peer = NULL;
+       u8 tid_no;
+       int ret = -EINVAL, retry_short = -1, retry_long = -1;
+
+       tid = info->attrs[NL80211_ATTR_TID_CONFIG];
+       if (!tid)
+               return -EINVAL;
+
+       ret = nla_parse_nested(attrs, NL80211_ATTR_TID_MAX, tid,
+                              nl80211_attr_tid_policy, info->extack);
+       if (ret)
+               return ret;
+
+       if (!attrs[NL80211_ATTR_TID])
+               return -EINVAL;
+
+       if (attrs[NL80211_ATTR_TID_RETRY_SHORT]) {
+               retry_short = 
nla_get_u8(attrs[NL80211_ATTR_TID_RETRY_SHORT]);
+               if (!retry_short ||
+                   retry_short > rdev->wiphy.max_data_retry_count)
+                       return -EINVAL;
+       }
+
+       if (attrs[NL80211_ATTR_TID_RETRY_LONG]) {
+               retry_long = 
nla_get_u8(attrs[NL80211_ATTR_TID_RETRY_LONG]);
+               if (!retry_long ||
+                   retry_long > rdev->wiphy.max_data_retry_count)
+                       return -EINVAL;
+       }
+
+       tid_no = nla_get_u8(attrs[NL80211_ATTR_TID]);
+       if (tid_no >= IEEE80211_FIRST_TSPEC_TSID)
+               return -EINVAL;

Not that important, but this tid_no check can be placed after
attrs[NL80211_ATTR_TID].

BTW, some special tid_no value (e.g. (u8)-1) could be used to notify 
driver
that retry settings should be applied for all the TIDs. IIUC the only
required change would be to modify this tid_no sanity check.

Sure, we can use that.

Regards,
Sergey

Thanks,
Tamizh.