[U-Boot] [PATCH 12/17] usb: mv_udc: Add cacheline length check

[Marek Vasut]

Check the length of system cacheline at compile-time and fail
if the system uses too long cachelines.

Signed-off-by: Marek Vasut <marex at denx.de>
Cc: Fabio Estevam <fabio.estevam at freescale.com>
Cc: Lei Wen <leiwen at marvell.com>
Cc: Otavio Salvador <otavio at ossystems.com.br>
Cc: Stefano Babic <sbabic at denx.de>
---
 drivers/usb/gadget/mv_udc.c |   10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/usb/gadget/mv_udc.c b/drivers/usb/gadget/mv_udc.c
index 394af6b..2076717 100644
--- a/drivers/usb/gadget/mv_udc.c
+++ b/drivers/usb/gadget/mv_udc.c
@@ -37,6 +37,16 @@
 #error This driver only supports one single controller.
 #endif
 
+/*
+ * Check if the system has too long cachelines. If the cachelines are
+ * longer then 128b, the driver will not be able flush/invalidate data
+ * cache over separate QH entries. We use 128b because one QH entry is
+ * 64b long and there are always two QH list entries for each endpoint.
+ */
+#if ARCH_DMA_MINALIGN > 128
+#error This driver can not work on systems with caches longer than 128b
+#endif
+
 #ifndef DEBUG
 #define DBG(x...) do {} while (0)
 #else
-- 
1.7.10.4