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From: Enric Balletbo Serra <eballetbo@gmail.com>
Date: Thu, 9 Jun 2016 10:10:47 +0200
Message-ID: <CAFqH_51792OS-mFSdTddjOL9+xdAk-ariP_sffS9=6ACK8ZdMQ@mail.gmail.com> (sfid-20160609_101144_482059_937EE25F)
Subject: Re: [PATCH v2 1/3] mwifiex: add a cfg80211 .get_tx_power operation callback
To: Javier Martinez Canillas <javier@osg.samsung.com>
Cc: linux-kernel@vger.kernel.org,
	Julian Calaby <julian.calaby@gmail.com>,
	Shengzhen Li <szli@marvell.com>,
	Enric Balletbo i Serra <enric.balletbo@collabora.com>,
	Amitkumar Karwar <akarwar@marvell.com>,
	Kalle Valo <kvalo@codeaurora.org>, netdev@vger.kernel.org,
	"linux-wireless@vger.kernel.org" <linux-wireless@vger.kernel.org>,
	Nishant Sarmukadam <nishants@marvell.com>
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Sender: linux-wireless-owner@vger.kernel.org
List-ID: <linux-wireless.vger.kernel.org>

2016-06-06 19:02 GMT+02:00 Javier Martinez Canillas <javier@osg.samsung.com>:
> The mwifiex driver implements a cfg80211 .set_tx_power operation handler
> but doesn't have the inverse .get_tx_power callback.
>
> This not only has the effect that the Tx power can't be reported to user
> space tools such as iwconfig and iwlist but also that the wireless core
> prints a warning when a new wiphy is created due an cfg80211 operation
> being implemented without its counterpart.
>
> After this patch, the Tx power is properly reported to user-space tools:
>
> $ iwlist mlan0 txpower
> mlan0     unknown transmit-power information.
>
>           Current Tx-Power=13 dBm       (19 mW)
>
> and also the following warning isn't shown anymore on the driver probe:
>
> WARNING: CPU: 3 PID: 127 at net/wireless/core.c:366 wiphy_new_nm+0x66c/0x6ac
> Modules linked in: mwifiex_sdio mwifiex
> CPU: 3 PID: 127 Comm: kworker/3:1 Tainted: G        W       4.7.0-rc1-next-20160531-00006-g569df5b983f3
> Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)
> Workqueue: events request_firmware_work_func
> [<c010e1ac>] (unwind_backtrace) from [<c010af38>] (show_stack+0x10/0x14)
> [<c010af38>] (show_stack) from [<c0323b9c>] (dump_stack+0x88/0x9c)
> [<c0323b9c>] (dump_stack) from [<c011a828>] (__warn+0xe8/0x100)
> [<c011a828>] (__warn) from [<c011a8f0>] (warn_slowpath_null+0x20/0x28)
> [<c011a8f0>] (warn_slowpath_null) from [<c06a42d4>] (wiphy_new_nm+0x66c/0x6ac)
> [<c06a42d4>] (wiphy_new_nm) from [<bf1c24cc>] (mwifiex_register_cfg80211+0x28/0x3f0 [mwifiex])
> [<bf1c24cc>] (mwifiex_register_cfg80211 [mwifiex]) from [<bf1a0018>] (mwifiex_fw_dpc+0x2b0/0x474 [mwifiex])
> [<bf1a0018>] (mwifiex_fw_dpc [mwifiex]) from [<c040eb74>] (request_firmware_work_func+0x30/0x58)
> [<c040eb74>] (request_firmware_work_func) from [<c012fe90>] (process_one_work+0x124/0x338)
> [<c012fe90>] (process_one_work) from [<c01300dc>] (worker_thread+0x38/0x4d4)
> [<c01300dc>] (worker_thread) from [<c01353b8>] (kthread+0xdc/0xf4)
> [<c01353b8>] (kthread) from [<c0107978>] (ret_from_fork+0x14/0x3c)
>
> Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
> ---
>
>  drivers/net/wireless/marvell/mwifiex/cfg80211.c | 24 ++++++++++++++++++++++++
>  1 file changed, 24 insertions(+)
>
> diff --git a/drivers/net/wireless/marvell/mwifiex/cfg80211.c b/drivers/net/wireless/marvell/mwifiex/cfg80211.c
> index ff948a922222..b17f3d09a2c7 100644
> --- a/drivers/net/wireless/marvell/mwifiex/cfg80211.c
> +++ b/drivers/net/wireless/marvell/mwifiex/cfg80211.c
> @@ -377,6 +377,29 @@ mwifiex_cfg80211_set_tx_power(struct wiphy *wiphy,
>  }
>
>  /*
> + * CFG802.11 operation handler to get Tx power.
> + */
> +static int
> +mwifiex_cfg80211_get_tx_power(struct wiphy *wiphy,
> +                             struct wireless_dev *wdev,
> +                             int *dbm)
> +{
> +       struct mwifiex_adapter *adapter = mwifiex_cfg80211_get_adapter(wiphy);
> +       struct mwifiex_private *priv = mwifiex_get_priv(adapter,
> +                                                       MWIFIEX_BSS_ROLE_ANY);
> +       int ret = mwifiex_send_cmd(priv, HostCmd_CMD_RF_TX_PWR,
> +                                  HostCmd_ACT_GEN_GET, 0, NULL, true);
> +
> +       if (ret < 0)
> +               return ret;
> +
> +       /* tx_power_level is set in HostCmd_CMD_RF_TX_PWR command handler */
> +       *dbm = priv->tx_power_level;
> +
> +       return 0;
> +}
> +
> +/*
>   * CFG802.11 operation handler to set Power Save option.
>   *
>   * The timeout value, if provided, is currently ignored.
> @@ -3940,6 +3963,7 @@ static struct cfg80211_ops mwifiex_cfg80211_ops = {
>         .set_default_key = mwifiex_cfg80211_set_default_key,
>         .set_power_mgmt = mwifiex_cfg80211_set_power_mgmt,
>         .set_tx_power = mwifiex_cfg80211_set_tx_power,
> +       .get_tx_power = mwifiex_cfg80211_get_tx_power,
>         .set_bitrate_mask = mwifiex_cfg80211_set_bitrate_mask,
>         .start_ap = mwifiex_cfg80211_start_ap,
>         .stop_ap = mwifiex_cfg80211_stop_ap,
> --
> 2.5.5
>

This fixes the WARN_ON and makes things work, thanks.

Tested-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>