From 49c5b45e28560fdd182874a15bb93c9510a59959 Mon Sep 17 00:00:00 2001
From: Feng Tang <feng.tang@intel.com>
Date: Thu, 21 Jan 2010 10:41:10 +0800
Subject: [PATCH] --- yaml --- r: 180893 b: refs/heads/master c:
 c587b6fa05106606053fc5e8e344f07cd34ace23 h: refs/heads/master i:   180891:
 a2e112fb34aacb772d6d6b401a39a4f549bd3da1 v: v3

---
 [refs]                     |  2 +-
 trunk/drivers/spi/dw_spi.c | 16 ++++++++++++++++
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/[refs] b/[refs]
index fd9e864dbca3..0cf19ef97ebf 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 99147b5c4167612a987860b661b9f8b79e66b81f
+refs/heads/master: c587b6fa05106606053fc5e8e344f07cd34ace23
diff --git a/trunk/drivers/spi/dw_spi.c b/trunk/drivers/spi/dw_spi.c
index f713af8309e3..d948ef4f3910 100644
--- a/trunk/drivers/spi/dw_spi.c
+++ b/trunk/drivers/spi/dw_spi.c
@@ -831,6 +831,22 @@ static void spi_hw_init(struct dw_spi *dws)
 	spi_mask_intr(dws, 0xff);
 	spi_enable_chip(dws, 1);
 	flush(dws);
+
+	/*
+	 * Try to detect the FIFO depth if not set by interface driver,
+	 * the depth could be from 2 to 256 from HW spec
+	 */
+	if (!dws->fifo_len) {
+		u32 fifo;
+		for (fifo = 2; fifo <= 257; fifo++) {
+			dw_writew(dws, txfltr, fifo);
+			if (fifo != dw_readw(dws, txfltr))
+				break;
+		}
+
+		dws->fifo_len = (fifo == 257) ? 0 : fifo;
+		dw_writew(dws, txfltr, 0);
+	}
 }
 
 int __devinit dw_spi_add_host(struct dw_spi *dws)