On Wed, Aug 04, 2010 at 10:50:50PM +0100, Alan Cox wrote:
> From: Jacob Pan <jacob.jun.pan@xxxxxxxxx>
>
> The Intel Moorestown platform has MPH and OTG EHCI controllers that have
> internal SRAM that could be used as descriptors DMA pool caching. The SRAM is
> exposed via PCI BAR1. The limitation here is the SRAM access should be 32bit
> aligned. A separate patch "EHCI: Make ehci_qh structure items all 32bit aligned"
> has been submitted to linux-usb mailling list.
>
> Signed-off-by: Jacob Pan <jacob.jun.pan@xxxxxxxxx>
> Signed-off-by: Alek Du <alek.du@xxxxxxxxx>
> Signed-off-by: Alan Cox <alan@xxxxxxxxxxxxxxx>
> ---
>
> drivers/usb/core/buffer.c | 10 ++++++++++
> drivers/usb/host/ehci-hcd.c | 3 ++-
> drivers/usb/host/ehci-pci.c | 39 +++++++++++++++++++++++++++++++++++++++
> drivers/usb/host/ehci.h | 8 +++++++-
> include/linux/usb/hcd.h | 2 ++
> 5 files changed, 60 insertions(+), 2 deletions(-)
>
>
> diff --git a/drivers/usb/core/buffer.c b/drivers/usb/core/buffer.c
> index 2c69654..150d4b8 100644
> --- a/drivers/usb/core/buffer.c
> +++ b/drivers/usb/core/buffer.c
> @@ -115,6 +115,11 @@ void *hcd_buffer_alloc(
> return kmalloc(size, mem_flags);
> }
>
> + /* we won't use internal SRAM as data payload, we can't get
> + any benefits from it */
> + if (hcd->has_sram && hcd->sram_no_payload)
> + return dma_alloc_coherent(NULL, size, dma, mem_flags);
Why not pass the device you are allocing the memory from here? You know
what it is, right?
> +
> for (i = 0; i < HCD_BUFFER_POOLS; i++) {
> if (size <= pool_max [i])
> return dma_pool_alloc(hcd->pool [i], mem_flags, dma);
> @@ -141,6 +146,11 @@ void hcd_buffer_free(
> return;
> }
>
> + if (hcd->has_sram && hcd->sram_no_payload) {
> + dma_free_coherent(NULL, size, addr, dma);
Same here.
And this seems a bit odd, why is this the first controller that needs
this type of allocation scheme?
thanks,
greg k-h
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
