diff options
Diffstat (limited to 'include/linux/ide.h')
| -rw-r--r-- | include/linux/ide.h | 19 |
1 files changed, 0 insertions, 19 deletions
diff --git a/include/linux/ide.h b/include/linux/ide.h index 96c9ce33ce4d..082fd9b7687b 100644 --- a/include/linux/ide.h +++ b/include/linux/ide.h @@ -228,25 +228,6 @@ typedef unsigned char byte; /* used everywhere */ #define PRD_ENTRIES (PAGE_SIZE / (2 * PRD_BYTES)) /* - * Our Physical Region Descriptor (PRD) table should be large enough - * to handle the biggest I/O request we are likely to see. Since requests - * can have no more than 256 sectors, and since the typical blocksize is - * two or more sectors, we could get by with a limit of 128 entries here for - * the usual worst case. Most requests seem to include some contiguous blocks, - * further reducing the number of table entries required. - * - * The driver reverts to PIO mode for individual requests that exceed - * this limit (possible with 512 byte blocksizes, eg. MSDOS f/s), so handling - * 100% of all crazy scenarios here is not necessary. - * - * As it turns out though, we must allocate a full 4KB page for this, - * so the two PRD tables (ide0 & ide1) will each get half of that, - * allowing each to have about 256 entries (8 bytes each) from this. - */ -#define PRD_BYTES 8 -#define PRD_ENTRIES (PAGE_SIZE / (2 * PRD_BYTES)) - -/* * Some more useful definitions */ #define IDE_MAJOR_NAME "hd" /* the same for all i/f; see also genhd.c */ |