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Subject: RE: [PATCH] libertas sdio: remove CMD_FUNC_INIT call
From: Lubomir Rintel <lkundrak@v3.sk>
To: Bing Zhao <bzhao@marvell.com>
Cc: Harro Haan <hrhaan@gmail.com>, Dan Williams <dcbw@redhat.com>,
	"libertas-dev@lists.infradead.org" <libertas-dev@lists.infradead.org>,
	"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
	"linux-wireless@vger.kernel.org" <linux-wireless@vger.kernel.org>,
	"John W. Linville" <linville@tuxdriver.com>,
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Date: Sun, 24 Feb 2013 19:31:33 +0100
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On Wed, 2013-02-20 at 17:59 -0800, Bing Zhao wrote:
> Hi Lubomir,
> 
> > > > @@ -825,20 +825,6 @@ static void if_sdio_finish_power_on(struct if_sdio_card *card)
> > > >
> > > >  	sdio_release_host(func);
> > > >
> > > > -	/*
> > > > -	 * FUNC_INIT is required for SD8688 WLAN/BT multiple functions
> > > > -	 */
> > > > -	if (card->model == MODEL_8688) {
> > > > -		struct cmd_header cmd;
> > > > -
> > > > -		memset(&cmd, 0, sizeof(cmd));
> > > > -
> > > > -		lbs_deb_sdio("send function INIT command\n");
> > > > -		if (__lbs_cmd(priv, CMD_FUNC_INIT, &cmd, sizeof(cmd),
> > > > -				lbs_cmd_copyback, (unsigned long) &cmd))
> > > > -			netdev_alert(priv->dev, "CMD_FUNC_INIT cmd failed\n");
> > > > -	}
> > > > -
> > >
> > > Removing FUNC_INIT could break things in some scenarios.
> > > Could you please test the following case?
> > >
> > > 1. insmod liberates -> download firmware, send FUNC_INIT, ...
> > > 2. rmmod libertas -> send FUNC_SHUTDOWN command to firmware; BT is still working.
> > > 3. insmod libertas -> skip firmware downloading, send FUNC_INIT, ...
> > >
> > > If FUNC_INIT is removed, I don't expect step 3 to work.
> > 
> > In case btmrvl_sdio is loaded, the driver always locks up in FUNC_INIT
> > upon probe time, thus I'm not able to proceed to further steps.
> > 
> > [  209.338953] [<c0502248>] (__schedule+0x610/0x764) from [<bf20ae24>] (__lbs_cmd+0xb8/0x130
> > [libertas])
> > [  209.348340] [<bf20ae24>] (__lbs_cmd+0xb8/0x130 [libertas]) from [<bf222474>]
> > (if_sdio_finish_power_on+0xec/0x1b0 [libertas_sdio])
> > [  209.360136] [<bf222474>] (if_sdio_finish_power_on+0xec/0x1b0 [libertas_sdio]) from [<bf2226c4>]
> > (if_sdio_power_on+0x18c/0x20c [libertas_sdio])
> > [  209.373052] [<bf2226c4>] (if_sdio_power_on+0x18c/0x20c [libertas_sdio]) from [<bf222944>]
> > (if_sdio_probe+0x200/0x31c [libertas_sdio])
> > [  209.385316] [<bf222944>] (if_sdio_probe+0x200/0x31c [libertas_sdio]) from [<bf01d820>]
> > (sdio_bus_probe+0x94/0xfc [mmc_core])
> > [  209.396748] [<bf01d820>] (sdio_bus_probe+0x94/0xfc [mmc_core]) from [<c02e729c>]
> > (driver_probe_device+0x12c/0x348)
> > [  209.407214] [<c02e729c>] (driver_probe_device+0x12c/0x348) from [<c02e7530>]
> > (__driver_attach+0x78/0x9c)
> > [  209.416798] [<c02e7530>] (__driver_attach+0x78/0x9c) from [<c02e5658>] (bus_for_each_dev+0x50/0x88)
> > [  209.425946] [<c02e5658>] (bus_for_each_dev+0x50/0x88) from [<c02e6810>]
> > (bus_add_driver+0x108/0x268)
> > [  209.435180] [<c02e6810>] (bus_add_driver+0x108/0x268) from [<c02e782c>]
> > (driver_register+0xa4/0x134)
> > [  209.444426] [<c02e782c>] (driver_register+0xa4/0x134) from [<bf22601c>]
> > (if_sdio_init_module+0x1c/0x3c [libertas_sdio])
> > [  209.455339] [<bf22601c>] (if_sdio_init_module+0x1c/0x3c [libertas_sdio]) from [<c00085b8>]
> > (do_one_initcall+0x98/0x174)
> > [  209.466236] [<c00085b8>] (do_one_initcall+0x98/0x174) from [<c0076504>] (load_module+0x1c5c/0x1f80)
> > [  209.475390] [<c0076504>] (load_module+0x1c5c/0x1f80) from [<c007692c>]
> > (sys_init_module+0x104/0x128)
> > [  209.484632] [<c007692c>] (sys_init_module+0x104/0x128) from [<c0008c40>]
> > (ret_fast_syscall+0x0/0x38)
> > 
> > In case btmrvl_sdio is _not_ loaded, insmod returns, but driver locks up
> > waiting for FUNC_INIT to finish:
> > 
> > [  300.538859] [<c0502248>] (__schedule+0x610/0x764) from [<bf1fae24>] (__lbs_cmd+0xb8/0x130
> > [libertas])
> > [  300.548600] [<bf1fae24>] (__lbs_cmd+0xb8/0x130 [libertas]) from [<bf212474>]
> > (if_sdio_finish_power_on+0xec/0x1b0 [libertas_sdio])
> > [  300.560398] [<bf212474>] (if_sdio_finish_power_on+0xec/0x1b0 [libertas_sdio]) from [<bf213230>]
> > (if_sdio_do_prog_firmware+0x414/0x454 [libertas_sdio])
> > [  300.574052] [<bf213230>] (if_sdio_do_prog_firmware+0x414/0x454 [libertas_sdio]) from [<bf1fffbc>]
> > (lbs_fw_loaded+0x24/0x58 [libertas])
> > [  300.586907] [<bf1fffbc>] (lbs_fw_loaded+0x24/0x58 [libertas]) from [<c02f02c0>]
> > (request_firmware_work_func+0xb0/0xf4)
> > [  300.597746] [<c02f02c0>] (request_firmware_work_func+0xb0/0xf4) from [<c003ae0c>]
> > (process_one_work+0x348/0x6a8)
> > [  300.608288] [<c003ae0c>] (process_one_work+0x348/0x6a8) from [<c003b408>]
> > (worker_thread+0x268/0x390)
> > [  300.617630] [<c003b408>] (worker_thread+0x268/0x390) from [<c00414b0>] (kthread+0xc0/0xd4)
> > [  300.625947] [<c00414b0>] (kthread+0xc0/0xd4) from [<c0008ce8>] (ret_from_fork+0x14/0x20)
> > [  300.634135] 2 locks held by kworker/0:1/19:
> > [  300.638383]  #0:  (events){.+.+.+}, at: [<c003accc>] process_one_work+0x208/0x6a8
> > [  300.646512]  #1:  ((&fw_work->work)){+.+.+.}, at: [<c003accc>] process_one_work+0x208/0x6a8
> 
> There seems to be a race condition in lbs_thread().
> 
> At line 582:
>  582                 if (!priv->fw_ready)
>  583                         continue;
> 
> The fw_ready is 0, so you never get the chance to execute the FUNC_INIT command.
> 
>  617                 /* Execute the next command */
>  618                 if (!priv->dnld_sent && !priv->cur_cmd)
>  619                         lbs_execute_next_command(priv);
> 
> 
> Could you try the following change?
> 
> diff --git a/drivers/net/wireless/libertas/if_sdio.c b/drivers/net/wireless/libe
> index 739309e..8f5d977 100644
> --- a/drivers/net/wireless/libertas/if_sdio.c
> +++ b/drivers/net/wireless/libertas/if_sdio.c
> @@ -825,6 +825,8 @@ static void if_sdio_finish_power_on(struct if_sdio_card *car
> 
>         sdio_release_host(func);
> 
> +       priv->fw_ready = 1;
> +
>         /*
>          * FUNC_INIT is required for SD8688 WLAN/BT multiple functions
>          */
> @@ -839,7 +841,6 @@ static void if_sdio_finish_power_on(struct if_sdio_card *car
>                         netdev_alert(priv->dev, "CMD_FUNC_INIT cmd failed\n");
>         }
> 
> -       priv->fw_ready = 1;
>         wake_up(&card->pwron_waitq);
> 
>         if (!card->started) {

Thank you.
Everything seem to work fine for me with the patch applied.

Regards,
--
Lubo