| Message ID | 20201027225454.3492351-12-bigeasy@linutronix.de |
|---|---|
| State | Awaiting Upstream |
| Delegated to: | David Miller |
| Headers | show |
| Series | in_interrupt() cleanup, part 2 | expand |
| Context | Check | Description |
|---|---|---|
| jkicinski/cover_letter | success | Link |
| jkicinski/fixes_present | success | Link |
| jkicinski/patch_count | success | Link |
| jkicinski/tree_selection | success | Clearly marked for net-next |
| jkicinski/subject_prefix | success | Link |
| jkicinski/source_inline | success | Was 0 now: 0 |
| jkicinski/verify_signedoff | success | Link |
| jkicinski/module_param | success | Was 0 now: 0 |
| jkicinski/build_32bit | fail | Errors and warnings before: 4 this patch: 4 |
| jkicinski/kdoc | success | Errors and warnings before: 0 this patch: 0 |
| jkicinski/verify_fixes | success | Link |
| jkicinski/checkpatch | fail | Link |
| jkicinski/build_allmodconfig_warn | success | Errors and warnings before: 0 this patch: 0 |
| jkicinski/header_inline | success | Link |
| jkicinski/stable | success | Stable not CCed |
diff --git a/drivers/net/wireless/realtek/rtlwifi/btcoexist/halbtcoutsrc.c b/drivers/net/wireless/realtek/rtlwifi/btcoexist/halbtcoutsrc.c index 2c05369b79e4d..2155a6699ef8d 100644 --- a/drivers/net/wireless/realtek/rtlwifi/btcoexist/halbtcoutsrc.c +++ b/drivers/net/wireless/realtek/rtlwifi/btcoexist/halbtcoutsrc.c @@ -47,30 +47,17 @@ static bool is_any_client_connect_to_ap(struct btc_coexist *btcoexist) { struct rtl_priv *rtlpriv = btcoexist->adapter; struct rtl_mac *mac = rtl_mac(rtlpriv); - struct rtl_sta_info *drv_priv; - u8 cnt = 0; + bool ret = false; if (mac->opmode == NL80211_IFTYPE_ADHOC || mac->opmode == NL80211_IFTYPE_MESH_POINT || mac->opmode == NL80211_IFTYPE_AP) { - if (in_interrupt() > 0) { - list_for_each_entry(drv_priv, &rtlpriv->entry_list, - list) { - cnt++; - } - } else { - spin_lock_bh(&rtlpriv->locks.entry_list_lock); - list_for_each_entry(drv_priv, &rtlpriv->entry_list, - list) { - cnt++; - } - spin_unlock_bh(&rtlpriv->locks.entry_list_lock); - } + spin_lock_bh(&rtlpriv->locks.entry_list_lock); + if (!list_empty(&rtlpriv->entry_list)) + ret = true; + spin_unlock_bh(&rtlpriv->locks.entry_list_lock); } - if (cnt > 0) - return true; - else - return false; + return ret; } static bool halbtc_legacy(struct rtl_priv *adapter)
is_any_client_connect_to_ap() is using in_interrupt() to determine whether it should acquire the lock prior accessing the list. The usage of in_interrupt() in drivers is phased out and Linus clearly requested that code which changes behaviour depending on context should either be separated or the context be conveyed in an argument passed by the caller, which usually knows the context. The function is called from: - halbtc_get() - halbtc_get() halbtc_get_wifi_link_status() - halbtc_display_dbg_msg() halbtc_display_wifi_status() halbtc_get_wifi_link_status() All top level callers are part of the btc_coexist callback inferface and are never invoked from a context which can hold the lock already. The contexts which hold the lock are either protecting list add/del operations or list walks which never call into any of the btc_coexist interfaces. In fact the conditional is outright dangerous because if this function would be invoked from a BH disabled context the check would avoid taking the lock while on another CPU the list could be manipulated under the lock. Remove the in_interrupt() check and always acquire the lock. To simplify the code further use list_empty() instead of walking the list and counting the entries just to check the count for > 0 at the end. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Ping-Ke Shih <pkshih@realtek.com> Cc: Kalle Valo <kvalo@codeaurora.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jakub Kicinski <kuba@kernel.org> Cc: linux-wireless@vger.kernel.org Cc: netdev@vger.kernel.org --- .../realtek/rtlwifi/btcoexist/halbtcoutsrc.c | 25 +++++-------------- 1 file changed, 6 insertions(+), 19 deletions(-)