Re: [PATCH v3 05/12] bus: mhi: core: Prevent sending multiple RDDM entry callbacks

[Manivannan Sadhasivam]

On Thu, Oct 29, 2020 at 09:10:50PM -0700, Bhaumik Bhatt wrote:
> If an mhi_power_down() is initiated after the device has entered
> RDDM and a status callback was provided for it, it is possible
> that another BHI interrupt fires while waiting for the MHI
> RESET to be cleared. If that happens, MHI host would have moved
> a "disabled" execution environment and the check to allow sending
> an RDDM status callback will pass when it is should not. Add a
> check to see if MHI is in an active state before proceeding.
> 
> Signed-off-by: Bhaumik Bhatt <bbhatt@xxxxxxxxxxxxxx>

Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>

Thanks,
Mani

> ---
>  drivers/bus/mhi/core/main.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c
> index 1f32d67..172b48b 100644
> --- a/drivers/bus/mhi/core/main.c
> +++ b/drivers/bus/mhi/core/main.c
> @@ -399,6 +399,10 @@ irqreturn_t mhi_intvec_threaded_handler(int irq_number, void *priv)
>  
>  	 /* If device supports RDDM don't bother processing SYS error */
>  	if (mhi_cntrl->rddm_image) {
> +		/* host may be performing a device power down already */
> +		if (!mhi_is_active(mhi_cntrl))
> +			goto exit_intvec;
> +
>  		if (mhi_cntrl->ee == MHI_EE_RDDM && mhi_cntrl->ee != ee) {
>  			mhi_cntrl->status_cb(mhi_cntrl, MHI_CB_EE_RDDM);
>  			wake_up_all(&mhi_cntrl->state_event);
> -- 
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