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From: Michal Kazior <michal.kazior@tieto.com>
Date: Tue, 15 Nov 2016 11:13:15 +0100
Message-ID: <CA+BoTQmA0E+N46E3XkpqVPXSVkQNyZj2Qzrizk8iLdYzVthNQg@mail.gmail.com> (sfid-20161115_111332_994421_892E948D)
Subject: Re: [RFC 03/12] ath10k: htc: Changed order of wait target and ep connect
To: Erik Stromdahl <erik.stromdahl@gmail.com>
Cc: Kalle Valo <kvalo@qca.qualcomm.com>,
        linux-wireless <linux-wireless@vger.kernel.org>,
        "ath10k@lists.infradead.org" <ath10k@lists.infradead.org>
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On 14 November 2016 at 17:33, Erik Stromdahl <erik.stromdahl@gmail.com> wro=
te:
> This patch changes the order in which the driver waits for the
> target to become ready and the service connect of the HTC
> control service.
>
> The HTC control service is connected before the driver starts
> waiting for the HTC ready control message.
>
> The reason for this is that the HTC ready control message is
> transmitted on EP 0 and that sdio/mbox based systems will ignore
> messages received on unconnected endpoints.
>
> Signed-off-by: Erik Stromdahl <erik.stromdahl@gmail.com>
> ---
>  drivers/net/wireless/ath/ath10k/htc.c |   32 ++++++++++++++++-----------=
-----
>  1 file changed, 16 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/net/wireless/ath/ath10k/htc.c b/drivers/net/wireless=
/ath/ath10k/htc.c
> index e3f7bf4..7257366 100644
> --- a/drivers/net/wireless/ath/ath10k/htc.c
> +++ b/drivers/net/wireless/ath/ath10k/htc.c
> @@ -606,6 +606,22 @@ int ath10k_htc_wait_target(struct ath10k_htc *htc)
>         u16 credit_count;
>         u16 credit_size;
>
> +       /* setup our pseudo HTC control endpoint connection */
> +       memset(&conn_req, 0, sizeof(conn_req));
> +       memset(&conn_resp, 0, sizeof(conn_resp));
> +       conn_req.ep_ops.ep_tx_complete =3D ath10k_htc_control_tx_complete=
;
> +       conn_req.ep_ops.ep_rx_complete =3D ath10k_htc_control_rx_complete=
;
> +       conn_req.max_send_queue_depth =3D ATH10K_NUM_CONTROL_TX_BUFFERS;
> +       conn_req.service_id =3D ATH10K_HTC_SVC_ID_RSVD_CTRL;
> +
> +       /* connect fake service */
> +       status =3D ath10k_htc_connect_service(htc, &conn_req, &conn_resp)=
;
> +       if (status) {
> +               ath10k_err(ar, "could not connect to htc service (%d)\n",
> +                          status);
> +               return status;
> +       }
> +

How is this supposed to work? ath10k_htc_connect_service() requires
htc->target_credit_size to compute tx_credits_per_max_message. Or am I
missing something? Applying this patch alone results in:

[    6.680101] divide error: 0000 [#1] SMP
[    6.681342] Modules linked in: ath10k_pci(O) ath10k_core(O) ath
mac80211 cfg80211
[    6.684876] CPU: 3 PID: 823 Comm: kworker/u8:2 Tainted: G        W
O    4.9.0-rc4-wt-ath+ #79
[    6.688051] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
BIOS 1.7.5-20140531_083030-gandalf 04/01/2014
[    6.691644] Workqueue: ath10k_wq ath10k_core_register_work [ath10k_core]
[    6.694309] task: ffff88000a190000 task.stack: ffffc900006d4000
[    6.695458] RIP: 0010:[<ffffffffa01ae46b>]  [<ffffffffa01ae46b>]
ath10k_htc_connect_service+0x21b/0x420 [ath10k_core]


Micha=C5=82