[U-Boot] [PATCH 3/4] ehci-hcd.c: Add a new USB_DMA_MINALIGN define for cache alignment

Marek Vasut
2012-06-14T19:29:10Z

Dear Tom Rini,

> The USB spec says that 32 bytes is the minimum required alignment.
> However on some platforms we have a larger minimum requirement for cache
> coherency. In those cases, use that value rather than the USB spec
> minimum.
>
> Cc: Marek Vasut <marex@denx.de>
> Signed-off-by: Tom Rini <trini@ti.com>
> ---
> drivers/usb/host/ehci-hcd.c | 23 +++++++++++++++++------
> 1 file changed, 17 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
> index 04300be..45725f5 100644
> --- a/drivers/usb/host/ehci-hcd.c
> +++ b/drivers/usb/host/ehci-hcd.c
> @@ -29,12 +29,23 @@
>
> #include "ehci.h"
>
> -int rootdev;
> -struct ehci_hccr *hccr; /* R/O registers, not need for volatile */
> -volatile struct ehci_hcor *hcor;
> +/*
> + * The EHCI spec says that we must align to at least 32 bytes. However,
> + * some platforms require larger alignment.
> + */
> +#if ARCH_DMA_MINALIGN > 32
> +#define USB_DMA_MINALIGN ARCH_DMA_MINALIGN
> +#else
> +#define USB_DMA_MINALIGN 32
> +#endif

Don't we have some common header for these?

> +
> +int rootdev __attribute__((aligned(USB_DMA_MINALIGN)));
> +/* R/O registers, not need for volatile */
> +struct ehci_hccr *hccr __attribute__((aligned(USB_DMA_MINALIGN)));
> +volatile struct ehci_hcor *hcor
> __attribute__((aligned(USB_DMA_MINALIGN)));
>
> static uint16_t portreset;
> -static struct QH qh_list __attribute__((aligned(32)));
> +static struct QH qh_list __attribute__((aligned(USB_DMA_MINALIGN)));
>
> static struct descriptor {
> struct usb_hub_descriptor hub;
> @@ -207,8 +218,8 @@ static int
> ehci_submit_async(struct usb_device *dev, unsigned long pipe, void
> *buffer, int length, struct devrequest *req)
> {
> - static struct QH qh __attribute__((aligned(32)));
> - static struct qTD qtd[3] __attribute__((aligned (32)));
> + static struct QH qh __attribute__((aligned(USB_DMA_MINALIGN)));
> + static struct qTD qtd[3] __attribute__((aligned(USB_DMA_MINALIGN)));
> int qtd_counter = 0;
>
> volatile struct qTD *vtd;

Best regards,
Marek Vasut