On Mon, 29 Oct 2007 22:17:40 -0600
Robert Hancock <[email protected]> wrote:
> In the sata_nv driver, when running in ADMA mode, we can do 64-bit DMA.
> However, when an ATAPI device like a DVD drive is connected, we can't
> use ADMA mode, and so we have to abide by the restrictions of a normal
> SFF ATA controller and can only do 32-bit DMA. We detect this and try to
> set the blk_queue_bounce_limit, blk_queue_segment_boundary and
> blk_queue_max_hw_segments to the values corresponding to a normal SFF
> controller.
What about the DMA padding buffer from nv_adma_port_start and internal
buffers for commands like request sense that don't come via the request
queue directly.
Also it seems nv_adma_use_reg_mode() can decide to send other commands
via the non ADMA interface even for ATA devices. Are we 100% certain it
never decides to let through a command with DMA via the register
interface in this case - what do you see if you instrument the function ?
Alan
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
