[PATCH] dw_spi: Fix missing final read in some polling situations

[PATCH] dw_spi: Fix missing final read in some polling situations

[Alan Cox]

From: Major Lee <major_lee-8+ZHUTgF1KZBDgjK7y7TUQ@public.gmane.org>

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.

Patch is against mainline (2.6.37-rc5).
Verified on SPI touch screen device.

Signed-off-by: Major Lee <major_lee-8+ZHUTgF1KZBDgjK7y7TUQ@public.gmane.org>
Signed-off-by: Alan Cox <alan-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
---

 drivers/spi/dw_spi.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)


diff --git a/drivers/spi/dw_spi.c b/drivers/spi/dw_spi.c
index 9c1d07b..497ecb3 100644
--- a/drivers/spi/dw_spi.c
+++ b/drivers/spi/dw_spi.c
@@ -419,6 +419,11 @@ 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);
 
 	dw_spi_xfer_done(dws);
 }


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