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Subject: Re: [PATCH] bus: ti-sysc: Fix external abort for am335x pruss probe
To:     Tony Lindgren <tony@atomide.com>, <linux-omap@vger.kernel.org>
CC:     Dave Gerlach <d-gerlach@ti.com>, Faiz Abbas <faiz_abbas@ti.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Grygorii Strashko <grygorii.strashko@ti.com>,
        Keerthy <j-keerthy@ti.com>, Nishanth Menon <nm@ti.com>,
        <linux-kernel@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>,
        Kishon Vijay Abraham <kishon@ti.com>
References: <20210915065032.45013-1-tony@atomide.com>
From:   Suman Anna <s-anna@ti.com>
Message-ID: <3fd1968e-491e-6d98-ec9c-d29baed3158f@ti.com>
Date:   Thu, 16 Sep 2021 11:54:40 -0500
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Hi Tony,

On 9/15/21 1:50 AM, Tony Lindgren wrote:
> Starting with v5.15-rc1, I'm now seeing am335x beaglebone black produce
> the following error on pruss probe:
> 
> Unhandled fault: external abort on non-linefetch (0x1008) at 0xe0326000
> 
> This seems to have started with the enabling of pruss for am335x in the
> dts files. Adding a read-back after write to the sysconfig register fixes
> the issue for me.

Let me take a look at this during the weekend. I did verify the AM335x PRUSS
when I posted the dts patches on 5.14-rc. You should be able to check as well
from your staging branch with PRUSS patches.

regards
Suman

> 
> Cc: Suman Anna <s-anna@ti.com>
> Signed-off-by: Tony Lindgren <tony@atomide.com>
> ---
>  drivers/bus/ti-sysc.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/bus/ti-sysc.c b/drivers/bus/ti-sysc.c
> --- a/drivers/bus/ti-sysc.c
> +++ b/drivers/bus/ti-sysc.c
> @@ -2037,6 +2037,9 @@ static int sysc_reset(struct sysc *ddata)
>  		sysc_val = sysc_read_sysconfig(ddata);
>  		sysc_val |= sysc_mask;
>  		sysc_write(ddata, sysc_offset, sysc_val);
> +
> +		/* Flush posted write */
> +		sysc_read_sysconfig(ddata);
>  	}
>  
>  	if (ddata->cfg.srst_udelay)
>