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Re: [Xen-devel] [PATCH 3 of 5] rombios/ata: Reading this status register has no relevant side effects



No relevant side effects according to some spec or according to the
current qemu implementation?

Does it have any "irrelevant" side effects?

On Mon, 2012-11-26 at 16:41 +0000, Andrew Cooper wrote:
> So taking two traps when one will do is pointless.  This codepath is on the 
> int
> 0x13 hot path, and removing it has about a 30% reduction in the number of 
> traps
> to Qemu during Win7 boot.
> 
> Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
> 
> diff -r c223c044afbf -r a8645d836a0e tools/firmware/rombios/rombios.c
> --- a/tools/firmware/rombios/rombios.c
> +++ b/tools/firmware/rombios/rombios.c
> @@ -2540,7 +2540,6 @@ static int await_ide(when_done,base,time
>    Bit32u time=0,last=0;
>    Bit16u status;
>    Bit8u result;
> -  status = inb(base + ATA_CB_STAT); // for the times you're supposed to 
> throw one away
>    for(;;) {
>      status = inb(base+ATA_CB_STAT);
>      time++;
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@xxxxxxxxxxxxx
> http://lists.xen.org/xen-devel



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