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

Tom Rini
2012-06-14T19:01:46Z

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
+
+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;
--
1.7.9.5