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Date: Mon, 4 Dec 2006 01:30:47 +0100 (MET)
From: Olaf Hering <olaf@aepfle.de>
To: Alan <alan@lxorguk.ukuu.org.uk>
Subject: Re: pata_sl82c105 can not reserve IO region
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On Sun, Dec 03, Alan wrote:

> On Sun, 3 Dec 2006 23:24:49 +0100 (MET)
> Olaf Hering <olaf@aepfle.de> wrote:
> 
> > This change seems to fix it, only a single reset occurs. I think that
> > one is normal when a CD is in the drive during bootup, maybe it leaves
> > the drive in a confused state.
> > 
> > @@ -167,9 +175,13 @@ static void sl82c105_reset_engine(struct
> >         struct pci_dev *pdev = to_pci_dev(ap->host->dev);
> >         u16 val;
> > 
> > +       udelay(42);
> >         pci_read_config_word(pdev, 0x7E, &val);
> > +       udelay(10);
> >         pci_write_config_word(pdev, 0x7E, val | 4);
> > +       udelay(10);
> >         pci_write_config_word(pdev, 0x7E, val & ~4);
> > +       udelay(42);
> >  }
> 
> Where do you get the delays from ? There is nothing in the documentation
> or errata sheets I have here on that subject. Is this guesswork, divine
> inspiration or an errata note I don't posess ?

Just guessing.
The udelay(10) calls can go, then it still works.
I moved the delays to the callers, which should have been equivalent,
but it failed again.