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Message-Id: <20101011163440.072e0227.akpm@linux-foundation.org>
Date: Mon, 11 Oct 2010 16:34:40 -0700
From: Andrew Morton <akpm@...ux-foundation.org>
To: James Hogan <james@...anarts.com>
Cc: Gary Zambrano <zambrano@...adcom.com>,
Jiri Pirko <jpirko@...hat.com>,
FUJITA Tomonori <fujita.tomonori@....ntt.co.jp>,
Hauke Mehrtens <hauke@...ke-m.de>,
Larry Finger <Larry.Finger@...inger.net>,
netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
"David S. Miller" <davem@...emloft.net>
Subject: Re: [PATCH] b44: fix resume, request_irq after hw reset
On Tue, 12 Oct 2010 00:22:12 +0100
James Hogan <james@...anarts.com> wrote:
> This driver was hanging on resume because it was requesting a shared irq
> that it wasn't ready to immediately handle, which was tested in
> request_irq because of the CONFIG_DEBUG_SHIRQ config option. The
> interrupt handler tried to read the interrupt status register but for
> some reason it hung the system.
>
> The request_irq is now moved a bit later after resetting the hardware
> which seems to fix it.
>
> Signed-off-by: James Hogan <james@...anarts.com>
> ---
> drivers/net/b44.c | 12 ++++++------
> 1 files changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/net/b44.c b/drivers/net/b44.c
> index 1e620e2..dbba981 100644
> --- a/drivers/net/b44.c
> +++ b/drivers/net/b44.c
> @@ -2296,12 +2296,6 @@ static int b44_resume(struct ssb_device *sdev)
> if (!netif_running(dev))
> return 0;
>
> - rc = request_irq(dev->irq, b44_interrupt, IRQF_SHARED, dev->name, dev);
> - if (rc) {
> - netdev_err(dev, "request_irq failed\n");
> - return rc;
> - }
> -
> spin_lock_irq(&bp->lock);
>
> b44_init_rings(bp);
> @@ -2309,6 +2303,12 @@ static int b44_resume(struct ssb_device *sdev)
> netif_device_attach(bp->dev);
> spin_unlock_irq(&bp->lock);
>
> + rc = request_irq(dev->irq, b44_interrupt, IRQF_SHARED, dev->name, dev);
> + if (rc) {
> + netdev_err(dev, "request_irq failed\n");
> + return rc;
> + }
> +
> b44_enable_ints(bp);
> netif_wake_queue(dev);
OK, running the interrupt handler before b44_init_hw() is presumably
the problem here.
The hardware surely won't be generating interrupts until we've run
b44_init_hw() and b44_enable_ints(), so this patch really is only to
keep CONFIG_DEBUG_SHIRQ happy.
--
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