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

Tom Rini trini at ti.com
Thu Jun 14 21:01:46 CEST 2012


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 at denx.de>
Signed-off-by: Tom Rini <trini at 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



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