Re: [PATCH] wifi: ath10k: poll service ready message before failing

[Kalle Valo <kvalo@kernel.org>]

Baochen Qiang <quic_bqiang@quicinc.com> writes:

> Currently host relies on CE interrupts to get notified that
> the service ready message is ready. This results in timeout
> issue if the interrupt is not fired, due to some unknown
> reasons. See below logs:
>
> [76321.937866] ath10k_pci 0000:02:00.0: wmi service ready event not received
> ...
> [76322.016738] ath10k_pci 0000:02:00.0: Could not init core: -110
>
> And finally it causes WLAN interface bring up failure.
>
> Change to give it one more chance here by polling CE rings,
> before failing directly.
>
> Tested-on: QCA6174 hw3.2 PCI WLAN.RM.4.4.1-00157-QCARMSWPZ-1
>
> Fixes: 5e3dd157d7e7 ("ath10k: mac80211 driver for Qualcomm Atheros
> 802.11ac CQA98xx devices")
> Reported-by: James Prestwood <prestwoj@gmail.com>
> Link:
> https://lore.kernel.org/linux-wireless/304ce305-fbe6-420e-ac2a-d61ae5e6ca1a@gmail.com/
> Signed-off-by: Baochen Qiang <quic_bqiang@quicinc.com>

[...]

> +		/* Sometimes the PCI HIF doesn't receive interrupt
> +		 * for the service ready message even if the buffer
> +		 * was completed. PCIe sniffer shows that it's
> +		 * because the corresponding CE ring doesn't fires
> +		 * it. Workaround here by polling CE rings once.
> +		 */
> +		ath10k_warn(ar, "failed to receive service ready completion, polling..\n");
> +
> +		for (i = 0; i < CE_COUNT; i++)
> +			ath10k_hif_send_complete_check(ar, i, 1);
> +
> +		time_left = wait_for_completion_timeout(&ar->wmi.service_ready,
> +							WMI_SERVICE_READY_TIMEOUT_HZ);
> +		if (!time_left)
> +			return -ETIMEDOUT;

I think it would be user friendly to also print the end result for the
polling, for example something like this:

if (!time_left) {
        ath10k_warn(ar, "polling timed out");
	return -ETIMEDOUT;
}

ath10k_warn(ar, "service ready completion received, continuing normally");

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