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Date:   Tue, 07 Apr 2020 18:34:05 -0700
From:   hemantk@codeaurora.org
To:     Jeffrey Hugo <jhugo@codeaurora.org>
Cc:     manivannan.sadhasivam@linaro.org, linux-arm-msm@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-arm-msm-owner@vger.kernel.org
Subject: Re: [PATCH v2 2/5] bus: mhi: core: Make sure to powerdown if
 mhi_sync_power_up fails
In-Reply-To: <1586278230-29565-3-git-send-email-jhugo@codeaurora.org>
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 <1586278230-29565-3-git-send-email-jhugo@codeaurora.org>
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On 2020-04-07 09:50, Jeffrey Hugo wrote:
> Powerdown is necessary if mhi_sync_power_up fails due to a timeout, to
> clean up the resources.  Otherwise a BUG could be triggered when
> attempting to clean up MSIs because the IRQ is still active from a
> request_irq().
> 
> Signed-off-by: Jeffrey Hugo <jhugo@codeaurora.org>
> ---
>  drivers/bus/mhi/core/pm.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c
> index 3285c9e..fbffc6b 100644
> --- a/drivers/bus/mhi/core/pm.c
> +++ b/drivers/bus/mhi/core/pm.c
> @@ -922,7 +922,11 @@ int mhi_sync_power_up(struct mhi_controller 
> *mhi_cntrl)
>  			   MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state),
>  			   msecs_to_jiffies(mhi_cntrl->timeout_ms));
> 
> -	return (MHI_IN_MISSION_MODE(mhi_cntrl->ee)) ? 0 : -EIO;
> +	ret = (MHI_IN_MISSION_MODE(mhi_cntrl->ee)) ? 0 : -EIO;

Does it make sense to return -ETIMEDOUT instead of -EIO if device fails 
to move to mission mode?
Controller can use this info as mhi_async_power_up() would not return 
-ETIMEDOUT.

> +	if (ret)
> +		mhi_power_down(mhi_cntrl, false);
> +
> +	return ret;
>  }
>  EXPORT_SYMBOL(mhi_sync_power_up);