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Subject: Re: [PATCH 3/3] brcmfmac: make setting SDIO workqueue WQ_HIGHPRI a
 module parameter
To:     Wright Feng <wright.feng@cypress.com>, franky.lin@broadcom.com,
        hante.meuleman@broadcom.com, kvalo@codeaurora.org,
        chi-hsien.lin@cypress.com
Cc:     linux-wireless@vger.kernel.org,
        brcm80211-dev-list.pdl@broadcom.com, tj@kernel.org
References: <1584604406-15452-1-git-send-email-wright.feng@cypress.com>
 <1584604406-15452-4-git-send-email-wright.feng@cypress.com>
From:   Arend Van Spriel <arend.vanspriel@broadcom.com>
Message-ID: <40e33702-d37f-085d-a5a7-7f09ae9e2629@broadcom.com>
Date:   Thu, 19 Mar 2020 09:55:46 +0100
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+ Tejun - regarding alloc_workqueue usage

On 3/19/2020 8:53 AM, Wright Feng wrote:
> With setting sdio_wq_highpri=1 in module parameters, tasks submitted to
> SDIO workqueue will put at the head of the queue and run immediately.
> This parameter is for getting higher TX/RX throughput with SDIO bus.
> 
> Signed-off-by: Wright Feng <wright.feng@cypress.com>
> Signed-off-by: Chi-hsien Lin <chi-hsien.lin@cypress.com>
> ---
>   .../wireless/broadcom/brcm80211/brcmfmac/common.c  |  5 +++++
>   .../wireless/broadcom/brcm80211/brcmfmac/common.h  |  2 ++
>   .../wireless/broadcom/brcm80211/brcmfmac/sdio.c    | 22 ++++++++++++++--------
>   3 files changed, 21 insertions(+), 8 deletions(-)
> 

[...]

> diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c
> index 3a08252..885e8bd 100644
> --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c
> +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c
> @@ -4342,9 +4342,21 @@ struct brcmf_sdio *brcmf_sdio_probe(struct brcmf_sdio_dev *sdiodev)
>   	bus->txminmax = BRCMF_TXMINMAX;
>   	bus->tx_seq = SDPCM_SEQ_WRAP - 1;
>   
> +	/* attempt to attach to the dongle */
> +	if (!(brcmf_sdio_probe_attach(bus))) {
> +		brcmf_err("brcmf_sdio_probe_attach failed\n");
> +		goto fail;
> +	}
> +
>   	/* single-threaded workqueue */
> -	wq = alloc_ordered_workqueue("brcmf_wq/%s", WQ_MEM_RECLAIM,
> -				     dev_name(&sdiodev->func1->dev));
> +	if (sdiodev->settings->sdio_wq_highpri) {
> +		wq = alloc_workqueue("brcmf_wq/%s",
> +				     WQ_HIGHPRI | WQ_MEM_RECLAIM | WQ_UNBOUND,
> +				     1, dev_name(&sdiodev->func1->dev));

So two things changed, 1) WQ_HIGHPRI flag added *and* 2) use 
allow_workqueue basically dropping __WQ_ORDERED. Not sure which one 
contributes to the behavior described in the commit message.

Regards,
Arend

> +	} else {
> +		wq = alloc_ordered_workqueue("brcmf_wq/%s", WQ_MEM_RECLAIM,
> +					     dev_name(&sdiodev->func1->dev));
> +	}
>   	if (!wq) {
>   		brcmf_err("insufficient memory to create txworkqueue\n");
>   		goto fail;