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. We add a cpp check to <usb.h> to define USB_DMA_MINALIGN and make use of it in ehci-hcd.c and musb_core.h. We cannot use MAX() here as we are not allowed to have tests inside of align(...).
Cc: Marek Vasut marex@denx.de Signed-off-by: Tom Rini trini@ti.com
-- Changes in v4: - Re-checking shows we do not need to add alignment to rootdev/hcor/hccr
Changes in v2: - Move test to <usb.h>, expand comment. --- drivers/usb/host/ehci-hcd.c | 6 +++--- drivers/usb/musb/musb_core.h | 2 +- include/usb.h | 10 ++++++++++ 3 files changed, 14 insertions(+), 4 deletions(-)
diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c index 04300be..d34c675 100644 --- a/drivers/usb/host/ehci-hcd.c +++ b/drivers/usb/host/ehci-hcd.c @@ -34,7 +34,7 @@ struct ehci_hccr *hccr; /* R/O registers, not need for volatile */ volatile struct ehci_hcor *hcor;
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 +207,8 @@ 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; diff --git a/drivers/usb/musb/musb_core.h b/drivers/usb/musb/musb_core.h index a8adcce..e914369 100644 --- a/drivers/usb/musb/musb_core.h +++ b/drivers/usb/musb/musb_core.h @@ -145,7 +145,7 @@ struct musb_regs { struct musb_epN_regs epN; } ep[16];
-} __attribute__((packed, aligned(32))); +} __attribute__((packed, aligned(USB_DMA_MINALIGN))); #endif
/* diff --git a/include/usb.h b/include/usb.h index 6da91e7..ba3d169 100644 --- a/include/usb.h +++ b/include/usb.h @@ -29,6 +29,16 @@ #include <usb_defs.h> #include <usbdescriptors.h>
+/* + * 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 + /* Everything is aribtrary */ #define USB_ALTSETTINGALLOC 4 #define USB_MAXALTSETTING 128 /* Hard limit */