Hi Stanislaw!
On Wed, 6 Oct 2010 18:04:35 +0200
Stanislaw Gruszka <sgruszka@xxxxxxxxxx> wrote:
> This is stable friendly backport of wireless-testing commit
> 3eecce527c7434dfd16517ce08b49632c8a26717 "iwlwifi: unify scan start
> checks". Wireless-testing version include also a lot of cleanups.
>
> On error case in {iwl3945,iwlagn}_request_scan we queue abort_scan work,
> which in a fact do nothing, so we never complete the scan. Thats gives
> "WARNING: at net/wireless/core.c:614 wdev_cleanup_work" and stopped
> network connection until reload iwlwifi modules. Return of -EIO, and
> stopping queuing any work is a fix.
>
> Note there are still many cases when we can get:
>
> WARNING: at net/wireless/core.c:614 wdev_cleanup_work
> WARNING: at net/mac80211/scan.c:266 ieee80211_scan_completed
> WARNING: at net/mac80211/scan.c:269 ieee80211_scan_complete
>
> which are not fixed. Unfortunately does not exist single, small fix
> for that problems, and we probably will see some more bug reports
> with scan warnings. As solution we rewrite iwl-scan.c code to avoid
> all possible race conditions. That quite big patch set is queued
> for 2.6.37 .
>
> Signed-off-by: Stanislaw Gruszka <sgruszka@xxxxxxxxxx>
> ---
Not that it matters much, but I've looked through it and couldn't find
anything wrong with it.
Reviewed-by: Florian Mickler <florian@xxxxxxxxxxx>
Regards,
Flo
> Patch is intended for wireless-2.6, or in case when it does not
> make 2.6.36 release, for -stable 2.6.36.y
>
> drivers/net/wireless/iwlwifi/iwl-3945.h | 2 +-
> drivers/net/wireless/iwlwifi/iwl-agn-lib.c | 18 ++++++------------
> drivers/net/wireless/iwlwifi/iwl-agn.h | 2 +-
> drivers/net/wireless/iwlwifi/iwl-core.h | 2 +-
> drivers/net/wireless/iwlwifi/iwl-scan.c | 14 +++++++++++---
> drivers/net/wireless/iwlwifi/iwl3945-base.c | 19 ++++++-------------
> 6 files changed, 26 insertions(+), 31 deletions(-)
>
> diff --git a/drivers/net/wireless/iwlwifi/iwl-3945.h b/drivers/net/wireless/iwlwifi/iwl-3945.h
> index bb2aeeb..98509c5 100644
> --- a/drivers/net/wireless/iwlwifi/iwl-3945.h
> +++ b/drivers/net/wireless/iwlwifi/iwl-3945.h
> @@ -295,7 +295,7 @@ extern const struct iwl_channel_info *iwl3945_get_channel_info(
> extern int iwl3945_rs_next_rate(struct iwl_priv *priv, int rate);
>
> /* scanning */
> -void iwl3945_request_scan(struct iwl_priv *priv, struct ieee80211_vif *vif);
> +int iwl3945_request_scan(struct iwl_priv *priv, struct ieee80211_vif *vif);
>
> /* Requires full declaration of iwl_priv before including */
> #include "iwl-io.h"
> diff --git a/drivers/net/wireless/iwlwifi/iwl-agn-lib.c b/drivers/net/wireless/iwlwifi/iwl-agn-lib.c
> index 8fd00a6..2be8faa 100644
> --- a/drivers/net/wireless/iwlwifi/iwl-agn-lib.c
> +++ b/drivers/net/wireless/iwlwifi/iwl-agn-lib.c
> @@ -1147,7 +1147,7 @@ static int iwl_get_channels_for_scan(struct iwl_priv *priv,
> return added;
> }
>
> -void iwlagn_request_scan(struct iwl_priv *priv, struct ieee80211_vif *vif)
> +int iwlagn_request_scan(struct iwl_priv *priv, struct ieee80211_vif *vif)
> {
> struct iwl_host_cmd cmd = {
> .id = REPLY_SCAN_CMD,
> @@ -1394,24 +1394,18 @@ void iwlagn_request_scan(struct iwl_priv *priv, struct ieee80211_vif *vif)
> scan->len = cpu_to_le16(cmd.len);
>
> set_bit(STATUS_SCAN_HW, &priv->status);
> - if (iwl_send_cmd_sync(priv, &cmd))
> + if (iwl_send_cmd_sync(priv, &cmd)) {
> + clear_bit(STATUS_SCAN_HW, &priv->status);
> goto done;
> + }
>
> queue_delayed_work(priv->workqueue, &priv->scan_check,
> IWL_SCAN_CHECK_WATCHDOG);
>
> - return;
> + return 0;
>
> done:
> - /* Cannot perform scan. Make sure we clear scanning
> - * bits from status so next scan request can be performed.
> - * If we don't clear scanning status bit here all next scan
> - * will fail
> - */
> - clear_bit(STATUS_SCAN_HW, &priv->status);
> - clear_bit(STATUS_SCANNING, &priv->status);
> - /* inform mac80211 scan aborted */
> - queue_work(priv->workqueue, &priv->abort_scan);
> + return -EIO;
> }
>
> int iwlagn_manage_ibss_station(struct iwl_priv *priv,
> diff --git a/drivers/net/wireless/iwlwifi/iwl-agn.h b/drivers/net/wireless/iwlwifi/iwl-agn.h
> index cc6464d..015da26 100644
> --- a/drivers/net/wireless/iwlwifi/iwl-agn.h
> +++ b/drivers/net/wireless/iwlwifi/iwl-agn.h
> @@ -216,7 +216,7 @@ void iwl_reply_statistics(struct iwl_priv *priv,
> struct iwl_rx_mem_buffer *rxb);
>
> /* scan */
> -void iwlagn_request_scan(struct iwl_priv *priv, struct ieee80211_vif *vif);
> +int iwlagn_request_scan(struct iwl_priv *priv, struct ieee80211_vif *vif);
>
> /* station mgmt */
> int iwlagn_manage_ibss_station(struct iwl_priv *priv,
> diff --git a/drivers/net/wireless/iwlwifi/iwl-core.h b/drivers/net/wireless/iwlwifi/iwl-core.h
> index 5e6ee3d..110de0f 100644
> --- a/drivers/net/wireless/iwlwifi/iwl-core.h
> +++ b/drivers/net/wireless/iwlwifi/iwl-core.h
> @@ -109,7 +109,7 @@ struct iwl_hcmd_utils_ops {
> __le16 fc, __le32 *tx_flags);
> int (*calc_rssi)(struct iwl_priv *priv,
> struct iwl_rx_phy_res *rx_resp);
> - void (*request_scan)(struct iwl_priv *priv, struct ieee80211_vif *vif);
> + int (*request_scan)(struct iwl_priv *priv, struct ieee80211_vif *vif);
> };
>
> struct iwl_apm_ops {
> diff --git a/drivers/net/wireless/iwlwifi/iwl-scan.c b/drivers/net/wireless/iwlwifi/iwl-scan.c
> index a4b3663..290140a 100644
> --- a/drivers/net/wireless/iwlwifi/iwl-scan.c
> +++ b/drivers/net/wireless/iwlwifi/iwl-scan.c
> @@ -298,6 +298,7 @@ EXPORT_SYMBOL(iwl_init_scan_params);
>
> static int iwl_scan_initiate(struct iwl_priv *priv, struct ieee80211_vif *vif)
> {
> + int ret;
> lockdep_assert_held(&priv->mutex);
>
> IWL_DEBUG_INFO(priv, "Starting scan...\n");
> @@ -308,9 +309,11 @@ static int iwl_scan_initiate(struct iwl_priv *priv, struct ieee80211_vif *vif)
> if (WARN_ON(!priv->cfg->ops->utils->request_scan))
> return -EOPNOTSUPP;
>
> - priv->cfg->ops->utils->request_scan(priv, vif);
> + ret = priv->cfg->ops->utils->request_scan(priv, vif);
> + if (ret)
> + clear_bit(STATUS_SCANNING, &priv->status);
> + return ret;
>
> - return 0;
> }
>
> int iwl_mac_hw_scan(struct ieee80211_hw *hw,
> @@ -380,6 +383,7 @@ void iwl_internal_short_hw_scan(struct iwl_priv *priv)
>
> void iwl_bg_start_internal_scan(struct work_struct *work)
> {
> + int ret;
> struct iwl_priv *priv =
> container_of(work, struct iwl_priv, start_internal_scan);
>
> @@ -414,7 +418,11 @@ void iwl_bg_start_internal_scan(struct work_struct *work)
> if (WARN_ON(!priv->cfg->ops->utils->request_scan))
> goto unlock;
>
> - priv->cfg->ops->utils->request_scan(priv, NULL);
> + ret = priv->cfg->ops->utils->request_scan(priv, NULL);
> + if (ret) {
> + clear_bit(STATUS_SCANNING, &priv->status);
> + priv->is_internal_short_scan = false;
> + }
> unlock:
> mutex_unlock(&priv->mutex);
> }
> diff --git a/drivers/net/wireless/iwlwifi/iwl3945-base.c b/drivers/net/wireless/iwlwifi/iwl3945-base.c
> index d31661c..fc82da0 100644
> --- a/drivers/net/wireless/iwlwifi/iwl3945-base.c
> +++ b/drivers/net/wireless/iwlwifi/iwl3945-base.c
> @@ -2799,7 +2799,7 @@ static void iwl3945_rfkill_poll(struct work_struct *data)
>
> }
>
> -void iwl3945_request_scan(struct iwl_priv *priv, struct ieee80211_vif *vif)
> +int iwl3945_request_scan(struct iwl_priv *priv, struct ieee80211_vif *vif)
> {
> struct iwl_host_cmd cmd = {
> .id = REPLY_SCAN_CMD,
> @@ -3000,25 +3000,18 @@ void iwl3945_request_scan(struct iwl_priv *priv, struct ieee80211_vif *vif)
> scan->len = cpu_to_le16(cmd.len);
>
> set_bit(STATUS_SCAN_HW, &priv->status);
> - if (iwl_send_cmd_sync(priv, &cmd))
> + if (iwl_send_cmd_sync(priv, &cmd)) {
> + clear_bit(STATUS_SCAN_HW, &priv->status);
> goto done;
> + }
>
> queue_delayed_work(priv->workqueue, &priv->scan_check,
> IWL_SCAN_CHECK_WATCHDOG);
>
> - return;
> + return 0;
>
> done:
> - /* can not perform scan make sure we clear scanning
> - * bits from status so next scan request can be performed.
> - * if we dont clear scanning status bit here all next scan
> - * will fail
> - */
> - clear_bit(STATUS_SCAN_HW, &priv->status);
> - clear_bit(STATUS_SCANNING, &priv->status);
> -
> - /* inform mac80211 scan aborted */
> - queue_work(priv->workqueue, &priv->abort_scan);
> + return -EIO;
> }
>
> static void iwl3945_bg_restart(struct work_struct *data)
--
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