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-rw-r--r--packages/linux/linux-2.6.18/atmel_spi-send-zeroes-when-tx_buf-is-not-set.patch48
1 files changed, 48 insertions, 0 deletions
diff --git a/packages/linux/linux-2.6.18/atmel_spi-send-zeroes-when-tx_buf-is-not-set.patch b/packages/linux/linux-2.6.18/atmel_spi-send-zeroes-when-tx_buf-is-not-set.patch
new file mode 100644
index 0000000000..0cf703d3df
--- /dev/null
+++ b/packages/linux/linux-2.6.18/atmel_spi-send-zeroes-when-tx_buf-is-not-set.patch
@@ -0,0 +1,48 @@
+From e9bce56d6d8913505049cde45d800bb69943f166 Mon Sep 17 00:00:00 2001
+From: Nicolas Ferre <nicolas.ferre@rfo.atmel.com>
+Date: Tue, 16 Jan 2007 15:15:36 +0100
+Subject: [ATMEL SPI] Send zeroes when tx_buf is not set
+
+send zeros when tx_buf is not set (according to the new spi
+specification by D.Brownell) cf.
+ http://lkml.org/lkml/2006/12/22/171
+ http://kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=4b1badf5d9ddfc46ad075ca5bfc465972c85cc7c
+
+Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
+---
+ drivers/spi/atmel_spi.c | 21 ++++++++++-----------
+ 1 file changed, 10 insertions(+), 11 deletions(-)
+
+Index: linux-2.6.18-avr32/drivers/spi/atmel_spi.c
+===================================================================
+--- linux-2.6.18-avr32.orig/drivers/spi/atmel_spi.c 2007-01-16 18:20:06.000000000 +0100
++++ linux-2.6.18-avr32/drivers/spi/atmel_spi.c 2007-01-16 18:20:57.000000000 +0100
+@@ -120,18 +120,17 @@ static void atmel_spi_next_xfer(struct s
+ len = BUFFER_SIZE;
+ }
+ if (tx_dma == INVALID_DMA_ADDRESS) {
+- if (xfer->tx_buf) {
+- tx_dma = as->buffer_dma;
+- if (len > BUFFER_SIZE)
+- len = BUFFER_SIZE;
++ tx_dma = as->buffer_dma;
++ if (len > BUFFER_SIZE)
++ len = BUFFER_SIZE;
++ if (xfer->tx_buf)
+ memcpy(as->buffer, xfer->tx_buf, len);
+- dma_sync_single_for_device(&as->pdev->dev,
+- as->buffer_dma, len,
+- DMA_TO_DEVICE);
+- } else {
+- /* Send undefined data; rx_dma is handy */
+- tx_dma = rx_dma;
+- }
++ else
++ /* no tx data: send zeros */
++ memset(as->buffer, 0, len);
++ dma_sync_single_for_device(&as->pdev->dev,
++ as->buffer_dma, len,
++ DMA_TO_DEVICE);
+ }
+
+ spi_writel(as, RPR, rx_dma);