lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20221107112243.GA2220@thinkpad>
Date:   Mon, 7 Nov 2022 16:52:43 +0530
From:   Manivannan Sadhasivam <mani@...nel.org>
To:     Qiang Yu <quic_qianyu@...cinc.com>
Cc:     mani@...nel.org, loic.poulain@...aro.org, mhi@...ts.linux.dev,
        linux-arm-msm@...r.kernel.org, linux-kernel@...r.kernel.org,
        quic_cang@...cinc.com, mrana@...cinc.com
Subject: Re: [PATCH] bus: mhi: host: Disable preemption while processing data
 events

On Thu, Nov 03, 2022 at 03:55:11PM +0800, Qiang Yu wrote:
> If data processing of an event is scheduled out because core
> is busy handling multiple irqs, this can starves the processing

s/starves/starve

> of MHI M0 state change event on another core. Fix this issue by
> disabling irq on the core processing data events.
> 
> Signed-off-by: Qiang Yu <quic_qianyu@...cinc.com>
> ---
>  drivers/bus/mhi/host/main.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/bus/mhi/host/main.c b/drivers/bus/mhi/host/main.c
> index f3aef77a..b58698d 100644
> --- a/drivers/bus/mhi/host/main.c
> +++ b/drivers/bus/mhi/host/main.c
> @@ -1027,13 +1027,14 @@ int mhi_process_data_event_ring(struct mhi_controller *mhi_cntrl,
>  
>  void mhi_ev_task(unsigned long data)
>  {
> +	unsigned long flags;
>  	struct mhi_event *mhi_event = (struct mhi_event *)data;
>  	struct mhi_controller *mhi_cntrl = mhi_event->mhi_cntrl;
>  
>  	/* process all pending events */
> -	spin_lock_bh(&mhi_event->lock);
> +	spin_lock_irqsave(&mhi_event->lock, flags);

Please add a comment stating why we are disabling local IRQs here. This will
help in understanding the code better.

Thanks,
Mani

>  	mhi_event->process_event(mhi_cntrl, mhi_event, U32_MAX);
> -	spin_unlock_bh(&mhi_event->lock);
> +	spin_unlock_irqrestore(&mhi_event->lock, flags);
>  }
>  
>  void mhi_ctrl_ev_task(unsigned long data)
> -- 
> 2.7.4
> 
> 

-- 
மணிவண்ணன் சதாசிவம்

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ