Hi Shimoda-san,
On Mon, Feb 9, 2015 at 9:16 AM, Yoshihiro Shimoda
<[email protected]> wrote:
> Some Renesas SoCs have the USB-DMAC. It is able to terminate transfers
> when a short packet is received, even if less bytes than the transfer
> counter size have been received. Also, it is able to send a short
> packet even if the packet size is not multiples of 8bytes.
>
> Since the previous code has used the interruption of USBHS controller
> when receiving packets even if this driver has used a dmac, a lot of
> interruptions has happened. This patch will reduce such interruptions.
>
> This patch allows to use the USB-DMAC on R-Car H2 and M2.
>
> Signed-off-by: Yoshihiro Shimoda <[email protected]>
> --- a/drivers/usb/renesas_usbhs/common.c
> +++ b/drivers/usb/renesas_usbhs/common.c
> @@ -487,6 +497,15 @@ static struct renesas_usbhs_platform_info
> *usbhs_parse_dt(struct device *dev)
> if (gpio > 0)
> dparam->enable_gpio = gpio;
>
> + switch (dparam->type) {
> + case USBHS_TYPE_R8A7790:
> + case USBHS_TYPE_R8A7791:
> + dparam->has_usb_dmac = 1;
> + break;
> + default:
> + break;
> + }
> +
> return info;
> }
> struct usbhs_priv *usbhs_pdev_to_priv(struct platform_device *pdev);
> diff --git a/drivers/usb/renesas_usbhs/fifo.c
> b/drivers/usb/renesas_usbhs/fifo.c
> index 3b77a1b..1e7dc6e 100644
> --- a/drivers/usb/renesas_usbhs/fifo.c
> +++ b/drivers/usb/renesas_usbhs/fifo.c
> @@ -847,10 +849,13 @@ static int usbhsf_dma_prepare_push(struct usbhs_pkt
> *pkt, int *is_done)
> usbhs_pipe_is_dcp(pipe))
> goto usbhsf_pio_prepare_push;
>
> - if (len & 0x7) /* 8byte alignment */
> + /* default: 8byte alignment */
> + if (!usbhs_get_dparam(priv, has_usb_dmac) && len & 0x7)
> goto usbhsf_pio_prepare_push;
So the has_usb_dmac flags indicates that DMA addresses are not limited to
8-byte alignment.
Can't this be handled by looking at a dma_mask, as set by the DMAC?
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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