When driver rtl8192cu is used with the debug level set to 3 or greater, the result is "sleeping function called from invalid context" due to an rcu_read_lock() call in the DM refresh routine in driver rtl8192c. This lock is not necessary as the USB driver does not use the struct being protected, thus the lock is set only when a PCI interface is active. This bug is reported in https://bugzilla.kernel.org/show_bug.cgi?id=42775. Reported-by: Ronald Wahl <ronald.wahl@xxxxxxxxxxx> Tested-by: Ronald Wahl <ronald.wahl@xxxxxxxxxxx> Signed-off-by: Larry Finger <Larry.Finger@xxxxxxxxxxxx> Cc: Stable <stable@xxxxxxxxxxxxxxx> Cc: Ronald Wahl <ronald.wahl@xxxxxxxxxxx> --- John, This patch should be added to 3.3, which is why I Cc'd Stable; however, as most people do not use the debug mode, it probably does not matter. I'll leave it to your judgement. Larry --- dm_common.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) --- Index: wireless-testing-new/drivers/net/wireless/rtlwifi/rtl8192c/dm_common.c =================================================================== --- wireless-testing-new.orig/drivers/net/wireless/rtlwifi/rtl8192c/dm_common.c +++ wireless-testing-new/drivers/net/wireless/rtlwifi/rtl8192c/dm_common.c @@ -1205,13 +1205,18 @@ static void rtl92c_dm_refresh_rate_adapt "PreState = %d, CurState = %d\n", p_ra->pre_ratr_state, p_ra->ratr_state); - rcu_read_lock(); - sta = ieee80211_find_sta(mac->vif, mac->bssid); + /* Only the PCI card uses sta in the update rate table + * callback routine */ + if (rtlhal->interface == INTF_PCI) { + rcu_read_lock(); + sta = ieee80211_find_sta(mac->vif, mac->bssid); + } rtlpriv->cfg->ops->update_rate_tbl(hw, sta, p_ra->ratr_state); p_ra->pre_ratr_state = p_ra->ratr_state; - rcu_read_unlock(); + if (rtlhal->interface == INTF_PCI) + rcu_read_unlock(); } } } -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
