[PATCH v3] i2c: tegra: Maintain CPU endianness

From: Dmitry Osipenko
Date: Mon Jan 26 2015 - 11:57:17 EST


Support CPU BE mode by adding endianness conversion for memcpy interactions.

Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
Acked-by: Alexandre Courbot <acourbot@xxxxxxxxxx>
---
Changelog:
v2: For consistency cpu_to_le32() changed to le32_to_cpu() because
i2c_writel() takes BE value in BE CPU mode and value is in LE format.
v3: Removed "val = 0;", it turned out it wasn't needed. For some reason
it wasn't working at first time, hope it was just me doing something
wrong and it's not a heisenbug. I've checked kernel with all memory
corruption detection options enabled and it didn't show any problems.

drivers/i2c/busses/i2c-tegra.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index 28b87e6..29f1433 100644
--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -286,6 +286,7 @@ static int tegra_i2c_empty_rx_fifo(struct tegra_i2c_dev *i2c_dev)
if (rx_fifo_avail > 0 && buf_remaining > 0) {
BUG_ON(buf_remaining > 3);
val = i2c_readl(i2c_dev, I2C_RX_FIFO);
+ val = cpu_to_le32(val);
memcpy(buf, &val, buf_remaining);
buf_remaining = 0;
rx_fifo_avail--;
@@ -344,6 +345,7 @@ static int tegra_i2c_fill_tx_fifo(struct tegra_i2c_dev *i2c_dev)
if (tx_fifo_avail > 0 && buf_remaining > 0) {
BUG_ON(buf_remaining > 3);
memcpy(&val, buf, buf_remaining);
+ val = le32_to_cpu(val);

/* Again update before writing to FIFO to make sure isr sees. */
i2c_dev->msg_buf_remaining = 0;
--
2.2.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/