linux-kernel - Re: [PATCH 2/4] Bluetooth: btmtksdio: handle runtime pm only when sdio

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Message-Id: <74A2D0D6-6A65-4832-BAFC-BCBA68F8DE78@holtmann.org>
Date:   Wed, 24 Nov 2021 15:53:23 +0100
From:   Marcel Holtmann <marcel@...tmann.org>
To:     Sean Wang <sean.wang@...iatek.com>
Cc:     Johan Hedberg <johan.hedberg@...il.com>,
        "Mark-YW Chen (陳揚文)" 
        <Mark-YW.Chen@...iatek.com>, Soul.Huang@...iatek.com,
        YN.Chen@...iatek.com, Leon.Yen@...iatek.com,
        Eric-SY.Chang@...iatek.com, Deren.Wu@...iatek.com,
        km.lin@...iatek.com, robin.chiu@...iatek.com,
        Eddie.Chen@...iatek.com, ch.yeh@...iatek.com,
        posh.sun@...iatek.com, ted.huang@...iatek.com,
        Eric.Liang@...iatek.com, Stella.Chang@...iatek.com,
        Tom.Chou@...iatek.com, steve.lee@...iatek.com, jsiuda@...gle.com,
        frankgor@...gle.com, jemele@...gle.com, abhishekpandit@...gle.com,
        michaelfsun@...gle.com, mcchou@...omium.org, shawnku@...gle.com,
        linux-bluetooth@...r.kernel.org,
        linux-mediatek@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/4] Bluetooth: btmtksdio: handle runtime pm only when
 sdio_func is available

Hi Sean,

> Runtime pm ops is not aware the sdio_func status that is probably
> being disabled by btmtksdio_close. Thus, we are only able to access the
> sdio_func for the runtime pm operations only when the sdio_func is
> available.
> 
> Fixes: 7f3c563c575e7 ("Bluetooth: btmtksdio: Add runtime PM support to SDIO based Bluetooth")
> Co-developed-by: Mark-yw Chen <mark-yw.chen@...iatek.com>
> Signed-off-by: Mark-yw Chen <mark-yw.chen@...iatek.com>
> Signed-off-by: Sean Wang <sean.wang@...iatek.com>
> ---
> drivers/bluetooth/btmtksdio.c | 6 ++++++
> 1 file changed, 6 insertions(+)
> 
> diff --git a/drivers/bluetooth/btmtksdio.c b/drivers/bluetooth/btmtksdio.c
> index 4f3412ad8fca..4c46c62e4623 100644
> --- a/drivers/bluetooth/btmtksdio.c
> +++ b/drivers/bluetooth/btmtksdio.c
> @@ -1037,6 +1037,9 @@ static int btmtksdio_runtime_suspend(struct device *dev)
> 	if (!bdev)
> 		return 0;
> 
> +	if (!test_bit(HCI_RUNNING, &bdev->hdev->flags))
> +		return 0;
> +
> 	sdio_claim_host(bdev->func);
> 
> 	sdio_writel(bdev->func, C_FW_OWN_REQ_SET, MTK_REG_CHLPCR, &err);
> @@ -1064,6 +1067,9 @@ static int btmtksdio_runtime_resume(struct device *dev)
> 	if (!bdev)
> 		return 0;
> 
> +	if (!test_bit(HCI_RUNNING, &bdev->hdev->flags))
> +		return 0;
> +
> 	sdio_claim_host(bdev->func);
> 
> 	sdio_writel(bdev->func, C_FW_OWN_REQ_CLR, MTK_REG_CHLPCR, &err);

I dislike looking at HCI_RUNNING since that check should be removed from a driver. Do you really need it? I mean, a driver should now if it is running or not.

Regards

Marcel