Thread (37 messages) 37 messages, 6 authors, 2014-01-07
STALE4554d REVIEWED: 1 (0M)

[PATCH v2 2/2] i2c: mv64xxx: Fix bus hang on A0 version of the Armada XP SoCs

From: Gregory CLEMENT <hidden>
Date: 2014-01-03 09:59:45
Also in: linux-i2c
Subsystem: i2c mv64xxx marvell and allwinner driver, i2c subsystem, i2c subsystem host drivers, the rest · Maintainers: Gregory CLEMENT, Andi Shyti, Linus Torvalds

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 driver now check the revision of the SoC. If the revision is not
more recent than the A0 or if the driver can't get the SoC revision
then it disables the offload mechanism.

Cc: stable at vger.kernel.org
Signed-off-by: Gregory CLEMENT <redacted>
Acked-by: Wolfram Sang <redacted>
---
 drivers/i2c/busses/i2c-mv64xxx.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/drivers/i2c/busses/i2c-mv64xxx.c b/drivers/i2c/busses/i2c-mv64xxx.c
index 8be7e42aa4de..634b04d241fb 100644
--- a/drivers/i2c/busses/i2c-mv64xxx.c
+++ b/drivers/i2c/busses/i2c-mv64xxx.c
@@ -24,6 +24,7 @@
 #include <linux/clk.h>
 #include <linux/err.h>
 #include <linux/delay.h>
+#include <linux/mvebu-soc-id.h>
 
 #define MV64XXX_I2C_ADDR_ADDR(val)			((val & 0x7f) << 1)
 #define MV64XXX_I2C_BAUD_DIV_N(val)			(val & 0x7)
@@ -779,8 +780,16 @@ mv64xxx_of_config(struct mv64xxx_i2c_data *drv_data,
 	 * Transaction Generator support and the errata fix.
 	 */
 	if (of_device_is_compatible(np, "marvell,mv78230-i2c")) {
-		drv_data->offload_enabled = true;
+		u32 dev, rev;
+
 		drv_data->errata_delay = true;
+		/*
+		 * Only revison more recent than A0 support offload
+		 * mechanism. In case we can't get the SoC revision
+		 * weplay safe and we don't enable it
+		 */
+		if (mvebu_get_soc_id(&rev, &dev) == 0 && dev > MV78XX0_A0_REV)
+			drv_data->offload_enabled = true;
 	}
 
 out:
-- 
1.8.1.2
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