linux-kernel - Re: [PATCH v3] ath10k: transmit queued frames after processing rx packets

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Message-ID: <20180523222002.GA26565@localhost.localdomain>
Date:   Thu, 24 May 2018 00:20:02 +0200
From:   Niklas Cassel <niklas.cassel@...aro.org>
To:     Kalle Valo <kvalo@....qualcomm.com>
Cc:     ath10k@...ts.infradead.org, linux-wireless@...r.kernel.org,
        netdev@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3] ath10k: transmit queued frames after processing rx
 packets

On Thu, May 24, 2018 at 12:15:08AM +0200, Niklas Cassel wrote:
> This problem cannot be reproduced on low-latency devices, e.g. pci,
> since they call ath10k_mac_tx_push_pending() from
> ath10k_htt_txrx_compl_task(). ath10k_htt_txrx_compl_task() is not called
> on high-latency devices.
> Fix the problem by calling ath10k_mac_tx_push_pending(), after
> processing rx packets, just like for low-latency devices, also in the
> SDIO case. Since we are calling ath10k_mac_tx_push_pending() directly,
> we also need to export it.
> 

Even if we are now calling ath10k_mac_tx_push_pending each time we process rx packets,
the number of packets we actually queue from ath10k_mac_tx_push_pending are quite few:

>From running iperf for 20 seconds:

# grep ath10k_mac_tx_push_txq /sys/kernel/debug/tracing/trace | grep -v ath10k_mac_op_wake_tx_queue | wc -l
233
number of times ath10k_mac_tx_push_txq was called, but not from ath10k_mac_op_wake_tx_queue,
i.e. number of times ath10k_mac_tx_push_txq was called from ath10k_mac_tx_push_pending.

# grep ath10k_mac_tx_push_txq /sys/kernel/debug/tracing/trace | grep -v ath10k_mac_tx_push_pending | wc -l
28415
number of times ath10k_mac_tx_push_txq was called, but not from ath10k_mac_tx_push_pending,
i.e number of times ath10k_mac_tx_push_txq was called from ath10k_mac_op_wake_tx_queue.

Regards,
Niklas