From 3d0b6087f3f2c88caef25e1455ff8db0816d4e11 Mon Sep 17 00:00:00 2001
From: Major Lee <major_lee@wistron.com>
Date: Fri, 10 Dec 2010 10:13:49 +0000
Subject: [PATCH] dw_spi: Fix missing final read in some polling situations
There is a possibility that the last word of a transaction will be lost
if data is not ready. Re-read in poll_transfer() to solve this issue
when poll_mode is enabled.
Verified on SPI touch screen device.
Signed-off-by: Major Lee <major_lee@wistron.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
drivers/spi/dw_spi.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/drivers/spi/dw_spi.c b/drivers/spi/dw_spi.c
index 90439314cf67..0838c79861e4 100644
--- a/drivers/spi/dw_spi.c
+++ b/drivers/spi/dw_spi.c
@@ -413,6 +413,11 @@ static void poll_transfer(struct dw_spi *dws)
{
while (dws->write(dws))
dws->read(dws);
+ /*
+ * There is a possibility that the last word of a transaction
+ * will be lost if data is not ready. Re-read to solve this issue.
+ */
+ dws->read(dws);
transfer_complete(dws);
}
--
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