From: Marcelo Tosatti <marcelo.tosatti@cyclades.com>
To: Kumar Gala <galak@gate.crashing.org>
Cc: Andrew Morton <akpm@osdl.org>,
dave@cray.org, linux-kernel@vger.kernel.org,
iinuxppc-embedded@gate.crashing.org, linuxppc-dev@ozlabs.org,
wim@iguana.be
Subject: Re: [PATCH] powerpc: Add support for the MPC83xx watchdog
Date: Mon, 16 Jan 2006 20:41:15 -0200 [thread overview]
Message-ID: <20060116224115.GB17275@dmt.cnet> (raw)
In-Reply-To: <Pine.LNX.4.44.0601131618020.26648-100000@gate.crashing.org>
> +static unsigned long wdt_is_open;
> +static spinlock_t wdt_spinlock;
> +
> +static void mpc83xx_wdt_keepalive(void)
> +{
> + /* Ping the WDT */
> + spin_lock(&wdt_spinlock);
> + out_be16(&wd_base->swsrr, 0x556c);
> + out_be16(&wd_base->swsrr, 0xaa39);
> + spin_unlock(&wdt_spinlock);
> +}
> +
> +static ssize_t mpc83xx_wdt_write(struct file * file, const char __user * buf,
> + size_t count, loff_t * ppos)
> +{
> + if(count)
> + mpc83xx_wdt_keepalive();
> + return count;
> +}
> +
> +static int mpc83xx_wdt_open(struct inode * inode, struct file * file)
> +{
> + u32 tmp = SWCRR_SWEN;
> + if (test_and_set_bit(0, &wdt_is_open))
> + return -EBUSY;
Hi Kumar,
What do you need the spinlock for if the device can't be opened
by more than one process?
prev parent reply other threads:[~2006-01-17 0:47 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-01-13 22:18 [PATCH] powerpc: Add support for the MPC83xx watchdog Kumar Gala
2006-01-13 22:52 ` Andrew Morton
2006-01-13 22:50 ` Kumar Gala
2006-01-13 22:58 ` Andrew Morton
2006-01-16 22:41 ` Marcelo Tosatti [this message]
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