From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Ivan Mikhaylov <ivan@de.ibm.com>,
Alistair Popple <alistair@popple.id.au>,
Matt Porter <mporter@kernel.crashing.org>
Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
Joel Stanley <joel@ozlabs.au.ibm.com>,
Paul Mackerras <paulus@samba.org>,
Michael Ellerman <mpe@ellerman.id.au>
Subject: Re: [PATCH 4/4] arch/powerpc/44x/fsp2: wdt tcr update instead of whole rewrite
Date: Fri, 19 May 2017 20:30:06 +1000 [thread overview]
Message-ID: <1495189806.3092.111.camel@kernel.crashing.org> (raw)
In-Reply-To: <20170515130754.59363-5-ivan@de.ibm.com>
On Mon, 2017-05-15 at 16:07 +0300, Ivan Mikhaylov wrote:
> +#ifdef CONFIG_FSP2
> + /*
> + * Prevent a kernel panic caused by unintentionally clearing TCR
> + * watchdog bits. At this point in the kernel boot, the watchdog has
> + * already been enabled by u-boot. The original code's attempt to
> + * write to the TCR register results in an inadvertent clearing of the
> + * watchdog configuration bits, causing the 440 to reset.
> + */
> + tcr = mfspr(SPRN_TCR);
> + tcr &= TCR_WP_MASK; /* clear all bits except for TCR[WP] */
> + tcr |= TCR_DIE; /* enable decrementer */
> + mtspr(SPRN_TCR, tcr);
> +#else
This should be a runtime test, not a compile time option.
Cheers,
Ben.
prev parent reply other threads:[~2017-05-19 10:30 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-15 13:07 [PATCH 4/4] arch/powerpc/44x/fsp2: wdt tcr update instead of whole rewrite Ivan Mikhaylov
2017-05-19 10:24 ` Michael Ellerman
2017-05-19 15:47 ` Ivan Mikhaylov
2017-05-23 4:09 ` Michael Ellerman
2017-05-26 10:37 ` Michael Ellerman
2017-05-30 9:11 ` [4/4] " Michael Ellerman
2017-05-19 10:30 ` Benjamin Herrenschmidt [this message]
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