[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] [PATCH 1 of 5] rombios/keyboard: Don't needlessly poll the status register



On Mon, 2012-11-26 at 16:41 +0000, Andrew Cooper wrote:
> Repeated polling of the status register is not going to change its value,

but the passage of time while doing multiple polls might? If this is not
the case then something needs to be said about why not.

>  so
> don't needlessly take 8192 traps to Qemu when 1 will do.
> 
> Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
> 
> diff -r 0049de3827bc -r 1728fb789940 tools/firmware/rombios/rombios.c
> --- a/tools/firmware/rombios/rombios.c
> +++ b/tools/firmware/rombios/rombios.c
> @@ -1805,12 +1805,12 @@ keyboard_init()
>      while ( (inb(0x64) & 0x02) && (--max>0)) outb(0x80, 0x00);
>  
>      /* flush incoming keys */
> -    max=0x2000;
> +    max=2;
>      while (--max > 0) {
>          outb(0x80, 0x00);
>          if (inb(0x64) & 0x01) {
>              inb(0x60);
> -            max = 0x2000;
> +            max = 2;
>              }
>          }
>  
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@xxxxxxxxxxxxx
> http://lists.xen.org/xen-devel



_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel


 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.