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From: Matthew Wilcox <matthew@wil.cx>
To: Stephen Hemminger <shemminger@vyatta.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>,
	linux-pci@vger.kernel.org, netdev@vger.kernel.org
Subject: Re: [PATCH 1/9] PCI: vpd handle longer delays in access (rev3)
Date: Tue, 9 Sep 2008 14:23:09 -0600	[thread overview]
Message-ID: <20080909202309.GE2772@parisc-linux.org> (raw)
In-Reply-To: <20080909182056.936398506@vyatta.com>

On Tue, Sep 09, 2008 at 11:20:41AM -0700, Stephen Hemminger wrote:
> Accessing the VPD area can take a long time.  The existing 
> VPD access code fails consistently on my hardware. There are comments
> in the SysKonnect vendor driver that it can take up to 13ms per word. 
> 
> Change the access routines to:
>   * use a mutex rather than spinning with IRQ's disabled and lock held
>   * have a much longer timeout
>   * call cond_resched while spinning

> -		udelay(10);
> +		if (fatal_signal_pending(current))
> +			return -EINTR;
> +		cond_resched();

We're back to the hammering on the pci bus problem again.  However,
cond_resched() does tell us whether we rescheduled!

		if (!cond_resched())
			udelay(10);

-- 
Matthew Wilcox				Intel Open Source Technology Centre
"Bill, look, we understand that you're interested in selling us this
operating system, but compare it to ours.  We can't possibly take such
a retrograde step."

  reply	other threads:[~2008-09-09 20:23 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-09-09 18:20 [PATCH 0/9] PCI VPD related patches Stephen Hemminger
2008-09-09 18:20 ` [PATCH 1/9] PCI: vpd handle longer delays in access (rev3) Stephen Hemminger
2008-09-09 20:23   ` Matthew Wilcox [this message]
2008-09-09 18:20 ` [PATCH 2/9] PCI: revise VPD access interface (rev3) Stephen Hemminger
2008-09-09 18:20 ` [PATCH 3/9] PCI: add interface to set visible size of VPD (rev3) Stephen Hemminger
2008-09-09 18:20 ` [PATCH 4/9] sky2: set VPD size Stephen Hemminger
2008-09-09 18:20 ` [PATCH 5/9] sky2: move VPD display into debug interface Stephen Hemminger
2008-09-09 18:20 ` [PATCH 6/9] sky2: remove VPD eeprom Stephen Hemminger
2008-09-09 18:20 ` [PATCH 7/9] skge: set VPD size Stephen Hemminger
2008-09-09 18:20 ` [PATCH 8/9] skge: add VPD display into debug interface Stephen Hemminger
2008-09-09 18:20 ` [PATCH 9/9] skge: remove VPD eeprom Stephen Hemminger
  -- strict thread matches above, loose matches on Subject: below --
2008-09-25 16:48 [PATCH 0/9] PCI vpd patches (rev4) Stephen Hemminger
2008-09-25 16:48 ` [PATCH 1/9] PCI: vpd handle longer delays in access (rev3) Stephen Hemminger
2008-09-25 18:54   ` Matthew Wilcox

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