@@ -1091,7 +1091,7 @@ static void ahci_start_transfer(IDEDMA *dma)
goto out;
}
- if (!ahci_populate_sglist(ad, &s->sg, s->io_buffer_offset)) {
+ if (ahci_dma_prepare_buf(dma, is_write)) {
has_sglist = 1;
}
@@ -1143,7 +1143,7 @@ static int ahci_dma_prepare_buf(IDEDMA *dma, int is_write)
AHCIDevice *ad = DO_UPCAST(AHCIDevice, dma, dma);
IDEState *s = &ad->port.ifs[0];
- ahci_populate_sglist(ad, &s->sg, 0);
+ ahci_populate_sglist(ad, &s->sg, s->io_buffer_offset);
s->io_buffer_size = s->sg.size;
DPRINTF(ad->port_no, "len=%#x\n", s->io_buffer_size);
The intent of this patch is to further unify the creation and deletion of the sglist used for all AHCI transfers, including emulated PIO, ATAPI R/W, and native DMA R/W. By replacing ahci_start_transfer's call to ahci_populate_sglist with ahci_dma_prepare_buf, we reduce the number of direct calls where we manipulate the scatter-gather list in the AHCI code. To make this switch, the constant "0" passed as an offset in ahci_dma_prepare_buf is adjusted to use io_buffer_offset. For DMA pathways, this has no effect: io_buffer_offset is always updated to 0 at the beginning of a DMA transfer loop regardless. DMA pathways through ide_dma_cb() update the io_buffer_offset accordingly, and for circumstances where we might make several trips through this loop, this may actually correct a design flaw. For PIO pathways, the newly updated ahci_dma_prepare_buf will now prepare the sglist at the correct offset. It will also set io_buffer_size, but this is not used in the cmd_read_pio or cmd_write_pio pathways. Signed-off-by: John Snow <jsnow@redhat.com> --- hw/ide/ahci.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)