i2c: tegra: apply size limit quirk

payload_size is a 12 bit field in the HW register, so add a limit for
this size. That way we gracefully reject the message beforehand instead
of generating an OOPS while transferring. Verified using some older
Tegra2 documentation and a more recent Jetson TK1 board.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Reviewed-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>

diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index 0a1b6ea..78a3668 100644 (file)
--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -669,6 +669,12 @@ static const struct i2c_algorithm tegra_i2c_algo = {
        .functionality  = tegra_i2c_func,
 };
 
+/* payload size is only 12 bit */
+static struct i2c_adapter_quirks tegra_i2c_quirks = {
+       .max_read_len = 4096,
+       .max_write_len = 4096,
+};
+
 static const struct tegra_i2c_hw_feature tegra20_i2c_hw = {
        .has_continue_xfer_support = false,
        .has_per_pkt_xfer_complete_irq = false,
@@ -739,6 +745,7 @@ static int tegra_i2c_probe(struct platform_device *pdev)
        i2c_dev->base = base;
        i2c_dev->div_clk = div_clk;
        i2c_dev->adapter.algo = &tegra_i2c_algo;
+       i2c_dev->adapter.quirks = &tegra_i2c_quirks;
        i2c_dev->irq = irq;
        i2c_dev->cont_id = pdev->id;
        i2c_dev->dev = &pdev->dev;