Hi Shimoda-san, On Mon, Feb 9, 2015 at 9:16 AM, Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx> 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 <yoshihiro.shimoda.uh@xxxxxxxxxxx> > --- 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 -- geert@xxxxxxxxxxxxxx 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 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html