ia64/xen-unstable
changeset 6202:b310a1b71b54
Enable multi-word DMA mode 2 for the PIIX3 chipset
Without this patch, Linux PIIX3 driver would see ultra DMA and get confused
and ended up disabling DMA.
With the patch, we're able to see 3x increase in disk read throughput.
Signed-off-by: Winston Wang <winston.l.wang@intel.com>
Signed-off-by: Arun Sharma <arun.sharma@intel.com>
Without this patch, Linux PIIX3 driver would see ultra DMA and get confused
and ended up disabling DMA.
With the patch, we're able to see 3x increase in disk read throughput.
Signed-off-by: Winston Wang <winston.l.wang@intel.com>
Signed-off-by: Arun Sharma <arun.sharma@intel.com>
| author | adsharma@los-vmm.sc.intel.com |
|---|---|
| date | Mon Aug 15 12:50:38 2005 -0800 (2005-08-15) |
| parents | 75367adf6055 |
| children | 60d20acf8928 |
| files | tools/ioemu/hw/ide.c |
line diff
1.1 --- a/tools/ioemu/hw/ide.c Mon Aug 15 12:50:32 2005 -0800 1.2 +++ b/tools/ioemu/hw/ide.c Mon Aug 15 12:50:38 2005 -0800 1.3 @@ -430,6 +430,7 @@ static void ide_identify(IDEState *s) 1.4 put_le16(p + 59, 0x100 | s->mult_sectors); 1.5 put_le16(p + 60, s->nb_sectors); 1.6 put_le16(p + 61, s->nb_sectors >> 16); 1.7 + put_le16(p + 63, 0x07); 1.8 put_le16(p + 80, (1 << 1) | (1 << 2)); 1.9 put_le16(p + 82, (1 << 14)); 1.10 put_le16(p + 83, (1 << 14)); 1.11 @@ -460,7 +461,7 @@ static void ide_atapi_identify(IDEState 1.12 put_le16(p + 48, 1); /* dword I/O (XXX: should not be set on CDROM) */ 1.13 put_le16(p + 49, 1 << 9); /* LBA supported, no DMA */ 1.14 put_le16(p + 53, 3); /* words 64-70, 54-58 valid */ 1.15 - put_le16(p + 63, 0x103); /* DMA modes XXX: may be incorrect */ 1.16 + put_le16(p + 63, 0x07); /* Multi-word DMA mode 2 */ 1.17 put_le16(p + 64, 1); /* PIO modes */ 1.18 put_le16(p + 65, 0xb4); /* minimum DMA multiword tx cycle time */ 1.19 put_le16(p + 66, 0xb4); /* recommended DMA multiword tx cycle time */