ide: enable single word DMA
PATCH 1/1 ide: enable single word DMA
Windows XP doesn't enable DMA by default on dvd-rom devices emulated by QEMU. Furthermore if I try to manually enable DMA using Device Manager, the DMA mode chosen by Windows is inexplicably one of the few modes unsupported by QEMU: single word mode 2.
Since on virtual hardware single word DMA is not really slower than multi word DMA, it makes sense for QEMU to support single word dma as well.
This patch does exactly this.
Signed-off-by Stefano Stabellini <[email protected]>
---
hw/ide.c +6 -0
@@ -569,6 +569,7 @@ static void ide_identify(IDEState *s)put_le16 (p +59 ,0x100 | s->mult_sectors);put_le16 (p +60 , s->nb_sectors);put_le16 (p +61 , s->nb_sectors >>16 ); +put_le16 (p +62 ,0x07 );/* single word dma0-2 supported */ put_le16 (p +63 ,0x07 );/* mdma0-2 supported */ put_le16 (p +65 ,120 );put_le16 (p +66 ,120 );
@@ -620,6 +621,7 @@ static void ide_atapi_identify(IDEState *s)#ifdef USE_DMA_CDROM put_le16 (p +49 ,1 <<9 |1 <<8 );/* DMA and LBA supported */ put_le16 (p +53 ,7 );/* words 64-70, 54-58, 88 valid */ +put_le16 (p +62 ,7 );/* single word dma0-2 supported */ put_le16 (p +63 ,7 );/* mdma0-2 supported */ put_le16 (p +64 ,0x3f );/* PIO modes supported */ #else
@@ -2197,6 +2199,10 @@ static void ide_ioport_write(void *opaque, uint32_t addr, uint32_t val)put_le16 (s->identify_data +63 ,0x07 );put_le16 (s->identify_data +88 ,0x3f );break ; +case 0x02 :/* sigle word dma mode*/ +put_le16 (s->identify_data +62 ,0x07 | (1 << (val +8 ))); +put_le16 (s->identify_data +88 ,0x3f ); +break ;case 0x04 :/* mdma mode */ put_le16 (s->identify_data +63 ,0x07 | (1 << (val +8 )));put_le16 (s->identify_data +88 ,0x3f );