On Sun, Apr 09, 2006 at 12:29:42PM +0200, Jens Axboe wrote:
> On Fri, Apr 07 2006, Rachita Kothiyal wrote:
> 
> if (stat & DRQ_STAT)
> 
> checking for DRQ_STAT again doesn't make sense, how can it ever be
> anything but DRQ_STAT if DRQ_STAT is set?

Hi Jens,

Yes, you are right. The condition itself is redundant there as 
DRQ will always be set there. I will remove it.

> 
> > +			/* DRQ is set. Interrupt not welcome now. Ignore */
> > +			HWIF(drive)->OUTB((stat & 0xEF), IDE_STATUS_REG);
> > +			return ide_stopped;
> 
> And this looks very wrong, you can't write to the status register. Well
> you can, but then it's the command register! Writing stat & 0xef to the
> command register is an odd thing to do. I think you just want to clear
> the DRQ bit, which should be fine after it was read initially. How about
> 
> 
>         if (stat & DRQ_STAT)
>                 return ide_stopped;
> 
> Can you test that?

I tested this, but I see it fail a couple of times...sometimes it hung
while booting up the second kernel and sometimes the kernel paniced 
while shutting it down.(attached partial log for panic)

I see your point that writing to the status register is not a good idea.
I think what we want to do is just ignore this particular interrupt and 
let it continue.
Am not sure if clearing DRQ bit will achieve this. Please correct me if
I am wrong, but to clear the DRQ bit also we will have to write to the 
status register. 

Thanks
Rachita