[U-Boot] [PATCH v2 3/3] ehci-hcd.c, musb_core, usb.h: Add USB_DMA_MINALIGN define for cache alignment

Tom Rini
2012-06-14T21:45:23Z

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 v2:
- Move test to <usb.h>, expand comment.
---
drivers/usb/host/ehci-hcd.c | 13 +++++++------
drivers/usb/musb/musb_core.h | 2 +-
include/usb.h | 10 ++++++++++
3 files changed, 18 insertions(+), 7 deletions(-)

diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index 04300be..5a86117 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -29,12 +29,13 @@

#include "ehci.h"

-int rootdev;
-struct ehci_hccr *hccr; /* R/O registers, not need for volatile */
-volatile struct ehci_hcor *hcor;
+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 +208,8 @@ 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 */
--
1.7.9.5