linux-kernel - Re: [PATCH v2 2/9] remoteproc: mediatek: Support hanlding scp core 1 wdt timeout

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Date:   Thu, 8 Sep 2022 18:38:28 +0800
From:   Tinghan Shen <tinghan.shen@...iatek.com>
To:     <mathieu.poirier@...aro.org>
CC:     <Project_Global_Chrome_Upstream_Group@...iatek.com>,
        <bjorn.andersson@...aro.org>, <bleung@...omium.org>,
        <chrome-platform@...ts.linux.dev>, <devicetree@...r.kernel.org>,
        <dnojiri@...omium.org>, <enric.balletbo@...labora.com>,
        <groeck@...omium.org>, <gustavoars@...nel.org>,
        <keescook@...omium.org>, <krzk+dt@...nel.org>,
        <lee.jones@...aro.org>, <linux-arm-kernel@...ts.infradead.org>,
        <linux-kernel@...r.kernel.org>,
        <linux-mediatek@...ts.infradead.org>,
        <linux-remoteproc@...r.kernel.org>, <matthias.bgg@...il.com>,
        <pmalani@...omium.org>, <robh+dt@...nel.org>,
        <sebastian.reichel@...labora.com>, <tinghan.shen@...iatek.com>,
        <weishunc@...gle.com>
Subject: Re: [PATCH v2 2/9] remoteproc: mediatek: Support hanlding scp core 1 wdt timeout

Hi Mathieu,

> Hi Tinghan,
> 
> I have started reviewing this set and I expect comments to be spread out over a few
> days.  I will tell you when I am done.
> 
> Please see below for comments...
> 
> On Wed, Jun 08, 2022 at 04:35:46PM +0800, Tinghan Shen wrote:
> > MT8195 SCP is a dual-core processor. The SCP core 1 watchdog timeout
> > interrupt uses the same interrupt line of SCP core 0 watchdog timeout
> > interrupt.
> > 
> > Add support for handling SCP core 1 watchdog timeout interrupt in the
> > SCP IRQ handler.
> > 
> > Signed-off-by: Tinghan Shen <tinghan.shen@...iatek.com>
> > ---
> >  drivers/remoteproc/mtk_common.h |  4 ++++
> >  drivers/remoteproc/mtk_scp.c    | 27 ++++++++++++++++++++++++++-
> >  2 files changed, 30 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/remoteproc/mtk_common.h b/drivers/remoteproc/mtk_common.h
> > index ea6fa1100a00..73e8adf00de3 100644
> > --- a/drivers/remoteproc/mtk_common.h
> > +++ b/drivers/remoteproc/mtk_common.h
> > @@ -54,6 +54,10 @@
> >  #define MT8192_CORE0_WDT_IRQ		0x10030
> >  #define MT8192_CORE0_WDT_CFG		0x10034
> >  
> > +#define MT8195_SYS_STATUS		0x4004
> > +#define MT8195_CORE0_WDT		BIT(16)
> > +#define MT8195_CORE1_WDT		BIT(17)
> > +
> >  #define MT8195_L1TCM_SRAM_PDN_RESERVED_RSI_BITS		GENMASK(7, 4)
> >  
> >  #define SCP_FW_VER_LEN			32
> > diff --git a/drivers/remoteproc/mtk_scp.c b/drivers/remoteproc/mtk_scp.c
> > index 47b2a40e1b4a..3510c6d0bbc8 100644
> > --- a/drivers/remoteproc/mtk_scp.c
> > +++ b/drivers/remoteproc/mtk_scp.c
> > @@ -212,6 +212,31 @@ static void mt8192_scp_irq_handler(struct mtk_scp *scp)
> >  	}
> >  }
> >  
> > +static void mt8195_scp_irq_handler(struct mtk_scp *scp)
> > +{
> > +	u32 scp_to_host;
> > +
> > +	scp_to_host = readl(scp->reg_base + MT8192_SCP2APMCU_IPC_SET);
> > +
> > +	if (scp_to_host & MT8192_SCP_IPC_INT_BIT) {
> > +		scp_ipi_handler(scp);
> > +
> > +		/*
> > +		 * SCP won't send another interrupt until we clear
> > +		 * MT8192_SCP2APMCU_IPC.
> > +		 */
> > +		writel(MT8192_SCP_IPC_INT_BIT,
> > +		       scp->reg_base + MT8192_SCP2APMCU_IPC_CLR);
> > +	} else {
> > +		if (readl(scp->reg_base + MT8195_SYS_STATUS) & MT8195_CORE1_WDT) {
> > +			writel(1, scp->reg_base + MT8195_CORE1_WDT_IRQ);
> > +		} else {
> > +			writel(1, scp->reg_base + MT8192_CORE0_WDT_IRQ);
> > +			scp_wdt_handler(scp, scp_to_host);
> 
> Why is scp_wdt_handler() not called when CORE1 signals a watchdog failure?  If
> this is the intended behaviour there is no way for anyone but you to know that
> it is the case.  

It's becuase the handler of CORE1 timeout doesn't exist at this patch.
The CORE1 timeout handler is added at patch 7 of this series.

You're right. This makes people confused.
I'll combine this patch with the CORE1 timeout handler.

Best regards,
TingHan