i2c: mv64xxx: Fix bus hang on A0 version of the Armada XP SoCs

commit 6cf70ae928bae17077efc0d528dec49bc380438b upstream.

The first variants of Armada XP SoCs (A0 stepping) have issues related
to the i2c controller which prevent to use the offload mechanism and
lead to a kernel hang during boot.

The commit introduces a new the compatible string
marvell,mv78230-a0-i2c for the i2c controller. When this compatible
string is used the driver disables the offload mechanism and the
kernel no more hangs on these SoCs.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Reported-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 930ab3d403ae (i2c: mv64xxx: Add I2C Transaction Generator support)
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/i2c/busses/i2c-mv64xxx.c b/drivers/i2c/busses/i2c-mv64xxx.c
index d3e9cc3..6f02eb8 100644 (file)
--- a/drivers/i2c/busses/i2c-mv64xxx.c
+++ b/drivers/i2c/busses/i2c-mv64xxx.c
@@ -692,6 +692,7 @@ static const struct of_device_id mv64xxx_i2c_of_match_table[] = {
        { .compatible = "allwinner,sun4i-i2c", .data = &mv64xxx_i2c_regs_sun4i},
        { .compatible = "marvell,mv64xxx-i2c", .data = &mv64xxx_i2c_regs_mv64xxx},
        { .compatible = "marvell,mv78230-i2c", .data = &mv64xxx_i2c_regs_mv64xxx},
+       { .compatible = "marvell,mv78230-a0-i2c", .data = &mv64xxx_i2c_regs_mv64xxx},
        {}
 };
 MODULE_DEVICE_TABLE(of, mv64xxx_i2c_of_match_table);
@@ -783,6 +784,10 @@ mv64xxx_of_config(struct mv64xxx_i2c_data *drv_data,
                drv_data->errata_delay = true;
        }
 
+       if (of_device_is_compatible(np, "marvell,mv78230-a0-i2c")) {
+               drv_data->offload_enabled = false;
+               drv_data->errata_delay = true;
+       }
 out:
        return rc;
 #endif