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From: Adrian Hunter <adrian.hunter@intel.com>
To: Douglas Anderson <dianders@chromium.org>,
	Ulf Hansson <ulf.hansson@linaro.org>,
	Kalle Valo <kvalo@codeaurora.org>,
	Arend van Spriel <arend.vanspriel@broadcom.com>
Cc: brcm80211-dev-list.pdl@broadcom.com,
	linux-rockchip@lists.infradead.org,
	Double Lo <double.lo@cypress.com>,
	briannorris@chromium.org, linux-wireless@vger.kernel.org,
	Naveen Gupta <naveen.gupta@cypress.com>,
	Madhan Mohan R <madhanmohan.r@cypress.com>,
	mka@chromium.org, Wright Feng <wright.feng@cypress.com>,
	Chi-Hsien Lin <chi-hsien.lin@cypress.com>,
	netdev@vger.kernel.org, brcm80211-dev-list@cypress.com,
	Franky Lin <franky.lin@broadcom.com>,
	linux-kernel@vger.kernel.org,
	Hante Meuleman <hante.meuleman@broadcom.com>,
	YueHaibing <yuehaibing@huawei.com>,
	"David S. Miller" <davem@davemloft.net>
Subject: Re: [PATCH v4 5/5] brcmfmac: sdio: Don't tune while the card is off
Date: Mon, 17 Jun 2019 11:28:10 +0300
Message-ID: <dac34482-cf74-5db9-ec0f-124af0ace811@intel.com> (raw)
In-Reply-To: <20190613234153.59309-6-dianders@chromium.org>

On 14/06/19 2:41 AM, Douglas Anderson wrote:
> When Broadcom SDIO cards are idled they go to sleep and a whole
> separate subsystem takes over their SDIO communication.  This is the
> Always-On-Subsystem (AOS) and it can't handle tuning requests.
> 
> Specifically, as tested on rk3288-veyron-minnie (which reports having
> BCM4354/1 in dmesg), if I force a retune in brcmf_sdio_kso_control()
> when "on = 1" (aka we're transition from sleep to wake) by whacking:
>   bus->sdiodev->func1->card->host->need_retune = 1
> ...then I can often see tuning fail.  In this case dw_mmc reports "All
> phases bad!").  Note that I don't get 100% failure, presumably because
> sometimes the card itself has already transitioned away from the AOS
> itself by the time we try to wake it up.  If I force retuning when "on
> = 0" (AKA force retuning right before sending the command to go to
> sleep) then retuning is always OK.
> 
> NOTE: we need _both_ this patch and the patch to avoid triggering
> tuning due to CRC errors in the sleep/wake transition, AKA ("brcmfmac:
> sdio: Disable auto-tuning around commands expected to fail").  Though
> both patches handle issues with Broadcom's AOS, the problems are
> distinct:
> 1. We want to defer (but not ignore) asynchronous (like
>    timer-requested) tuning requests till the card is awake.  However,
>    we want to ignore CRC errors during the transition, we don't want
>    to queue deferred tuning request.
> 2. You could imagine that the AOS could implement retuning but we
>    could still get errors while transitioning in and out of the AOS.
>    Similarly you could imagine a seamless transition into and out of
>    the AOS (with no CRC errors) even if the AOS couldn't handle
>    tuning.
> 
> ALSO NOTE: presumably there is never a desperate need to retune in
> order to wake up the card, since doing so is impossible.  Luckily the
> only way the card can get into sleep state is if we had a good enough
> tuning to send it a sleep command, so presumably that "good enough"
> tuning is enough to wake us up, at least with a few retries.
> 
> Signed-off-by: Douglas Anderson <dianders@chromium.org>

Acked-by: Adrian Hunter <adrian.hunter@intel.com>

> ---
> 
> Changes in v4:
> - Adjust to API rename (Adrian).
> 
> Changes in v3:
> - ("brcmfmac: sdio: Don't tune while the card is off") new for v3.
> 
> Changes in v2: None
> 
>  drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c
> index ee76593259a7..629140b6d7e2 100644
> --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c
> +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c
> @@ -669,6 +669,10 @@ brcmf_sdio_kso_control(struct brcmf_sdio *bus, bool on)
>  
>  	sdio_retune_crc_disable(bus->sdiodev->func1);
>  
> +	/* Cannot re-tune if device is asleep; defer till we're awake */
> +	if (on)
> +		sdio_retune_hold_now(bus->sdiodev->func1);
> +
>  	wr_val = (on << SBSDIO_FUNC1_SLEEPCSR_KSO_SHIFT);
>  	/* 1st KSO write goes to AOS wake up core if device is asleep  */
>  	brcmf_sdiod_writeb(bus->sdiodev, SBSDIO_FUNC1_SLEEPCSR, wr_val, &err);
> @@ -729,6 +733,9 @@ brcmf_sdio_kso_control(struct brcmf_sdio *bus, bool on)
>  	if (try_cnt > MAX_KSO_ATTEMPTS)
>  		brcmf_err("max tries: rd_val=0x%x err=%d\n", rd_val, err);
>  
> +	if (on)
> +		sdio_retune_release(bus->sdiodev->func1);
> +
>  	sdio_retune_crc_enable(bus->sdiodev->func1);
>  
>  	return err;
> 


  reply index

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-06-13 23:41 [PATCH v4 0/5] brcmfmac: sdio: Deal better w/ transmission errors related to idle Douglas Anderson
2019-06-13 23:41 ` [PATCH v4 1/5] Revert "brcmfmac: disable command decode in sdio_aos" Douglas Anderson
2019-06-13 23:41 ` [PATCH v4 2/5] mmc: core: API to temporarily disable retuning for SDIO CRC errors Douglas Anderson
2019-06-14 12:04   ` Ulf Hansson
2019-06-14 16:41     ` Doug Anderson
2019-06-17  7:53       ` Ulf Hansson
2019-06-17  8:30   ` Adrian Hunter
2019-06-13 23:41 ` [PATCH v4 3/5] brcmfmac: sdio: Disable auto-tuning around commands expected to fail Douglas Anderson
2019-06-17  8:33   ` Adrian Hunter
2019-06-17 10:35   ` Arend Van Spriel
2019-06-13 23:41 ` [PATCH v4 4/5] mmc: core: Add sdio_retune_hold_now() and sdio_retune_release() Douglas Anderson
2019-06-14 12:09   ` Ulf Hansson
2019-06-14 16:38     ` Doug Anderson
2019-06-14 17:17       ` Arend Van Spriel
2019-06-17  8:46       ` Adrian Hunter
2019-06-17  8:34   ` Adrian Hunter
2019-06-13 23:41 ` [PATCH v4 5/5] brcmfmac: sdio: Don't tune while the card is off Douglas Anderson
2019-06-17  8:28   ` Adrian Hunter [this message]
2019-06-17 10:52   ` Arend Van Spriel

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