Re: PRD_ENTRIES is 256

[Bartlomiej Zolnierkiewicz <B.Zolnierkiewicz@elka.pw.edu.pl>]

On Wednesday 25 of February 2004 10:53, William Lee Irwin III wrote:
> PRD_ENTRIES is specified to be precisely 256; on platforms where
> PAGE_SIZE varies from 4KB the calculation in the current expression
> defining it is inaccurate, which may cause crashes. This patch changes
> it to the constant literal 256.

Ok, thanks.  However I cannot find 256 entries limit in any ATA document
and from looking at the code 512 entries shouldn't be a problem (?).

--bart

> -- wli
>
>
> ===== include/linux/ide.h 1.88 vs edited =====
> --- 1.88/include/linux/ide.h	Tue Feb 10 07:35:39 2004
> +++ edited/include/linux/ide.h	Wed Feb 25 01:46:45 2004
> @@ -224,7 +224,7 @@
>   * allowing each to have about 256 entries (8 bytes each) from this.
>   */
>  #define PRD_BYTES       8
> -#define PRD_ENTRIES     (PAGE_SIZE / (2 * PRD_BYTES))
> +#define PRD_ENTRIES     256
>
>  /*
>   * Some more useful definitions