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Date:   Mon, 3 Apr 2023 11:07:30 +0530
From:   Manivannan Sadhasivam <mani@kernel.org>
To:     Jeffrey Hugo <quic_jhugo@quicinc.com>
Cc:     mhi@lists.linux.dev, linux-arm-msm@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/2] bus: mhi: host: Remove duplicate ee check for syserr
Message-ID: <20230403053730.GI4627@thinkpad>
References: <1674597444-24543-1-git-send-email-quic_jhugo@quicinc.com>
 <1674597444-24543-2-git-send-email-quic_jhugo@quicinc.com>
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On Tue, Jan 24, 2023 at 02:57:23PM -0700, Jeffrey Hugo wrote:
> If we detect a system error via intvec, we only process the syserr if the
> current ee is different than the last observed ee.  The reason for this
> check is to prevent bhie from running multiple times, but with the single
> queue handling syserr, that is not possible.
> 
> The check can cause an issue with device recovery.  If PBL loads a bad SBL
> via BHI, but that SBL hangs before notifying the host of an ee change,
> then issuing soc_reset to crash the device and retry (after supplying a
> fixed SBL) will not recover the device as the host will observe a PBL->PBL
> transition and not process the syserr.  The device will be stuck until
> either the driver is reloaded, or the host is rebooted.  Instead, remove
> the check so that we can attempt to recover the device.
> 
> Signed-off-by: Jeffrey Hugo <quic_jhugo@quicinc.com>

Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>

- Mani

> Reviewed-by: Carl Vanderlip <quic_carlv@quicinc.com>
> ---
>  drivers/bus/mhi/host/main.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/bus/mhi/host/main.c b/drivers/bus/mhi/host/main.c
> index df0fbfe..0c3a009 100644
> --- a/drivers/bus/mhi/host/main.c
> +++ b/drivers/bus/mhi/host/main.c
> @@ -503,7 +503,7 @@ irqreturn_t mhi_intvec_threaded_handler(int irq_number, void *priv)
>  	}
>  	write_unlock_irq(&mhi_cntrl->pm_lock);
>  
> -	if (pm_state != MHI_PM_SYS_ERR_DETECT || ee == mhi_cntrl->ee)
> +	if (pm_state != MHI_PM_SYS_ERR_DETECT)
>  		goto exit_intvec;
>  
>  	switch (ee) {
> -- 
> 2.7.4
> 

-- 
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