This is a note to let you know that I've just added the patch titled
Revert "i2c: designware: detect when dynamic tar update is possible"
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
revert-i2c-designware-detect-when-dynamic-tar-update-is-possible.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 12688dc21f71f4dcc9e2b8b5556b0c6cc8df1491 Mon Sep 17 00:00:00 2001
From: Jarkko Nikula <jarkko.nikula@xxxxxxxxxxxxxxx>
Date: Mon, 13 Feb 2017 11:18:19 +0200
Subject: Revert "i2c: designware: detect when dynamic tar update is possible"
From: Jarkko Nikula <jarkko.nikula@xxxxxxxxxxxxxxx>
commit 12688dc21f71f4dcc9e2b8b5556b0c6cc8df1491 upstream.
This reverts commit 63d0f0a6952a1a02bc4f116b7da7c7887e46efa3.
It caused a regression on platforms where I2C controller is synthesized
with dynamic TAR update disabled. Detection code is testing is bit
DW_IC_CON_10BITADDR_MASTER in register DW_IC_CON read-only but fails to
restore original value in case bit is read-write.
Instead of fixing this we revert the commit since it was preparation for
the commit 0317e6c0f1dc ("i2c: designware: do not disable adapter after
transfer") which was also reverted.
Reported-by: Shah Nehal-Bakulchandra <Nehal-bakulchandra.Shah@xxxxxxx>
Reported-by: Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx>
Acked-By: Lucas De Marchi <lucas.demarchi@xxxxxxxxx>
Fixes: 63d0f0a6952a ("i2c: designware: detect when dynamic tar update is possible")
Signed-off-by: Jarkko Nikula <jarkko.nikula@xxxxxxxxxxxxxxx>
Signed-off-by: Wolfram Sang <wsa@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/i2c/busses/i2c-designware-core.c | 45 +++++++------------------------
drivers/i2c/busses/i2c-designware-core.h | 1
2 files changed, 11 insertions(+), 35 deletions(-)
--- a/drivers/i2c/busses/i2c-designware-core.c
+++ b/drivers/i2c/busses/i2c-designware-core.c
@@ -475,30 +475,28 @@ static int i2c_dw_wait_bus_not_busy(stru
static void i2c_dw_xfer_init(struct dw_i2c_dev *dev)
{
struct i2c_msg *msgs = dev->msgs;
- u32 ic_tar = 0;
+ u32 ic_con, ic_tar = 0;
/* Disable the adapter */
__i2c_dw_enable_and_wait(dev, false);
/* if the slave address is ten bit address, enable 10BITADDR */
- if (dev->dynamic_tar_update_enabled) {
+ ic_con = dw_readl(dev, DW_IC_CON);
+ if (msgs[dev->msg_write_idx].flags & I2C_M_TEN) {
+ ic_con |= DW_IC_CON_10BITADDR_MASTER;
/*
* If I2C_DYNAMIC_TAR_UPDATE is set, the 10-bit addressing
- * mode has to be enabled via bit 12 of IC_TAR register,
- * otherwise bit 4 of IC_CON is used.
+ * mode has to be enabled via bit 12 of IC_TAR register.
+ * We set it always as I2C_DYNAMIC_TAR_UPDATE can't be
+ * detected from registers.
*/
- if (msgs[dev->msg_write_idx].flags & I2C_M_TEN)
- ic_tar = DW_IC_TAR_10BITADDR_MASTER;
+ ic_tar = DW_IC_TAR_10BITADDR_MASTER;
} else {
- u32 ic_con = dw_readl(dev, DW_IC_CON);
-
- if (msgs[dev->msg_write_idx].flags & I2C_M_TEN)
- ic_con |= DW_IC_CON_10BITADDR_MASTER;
- else
- ic_con &= ~DW_IC_CON_10BITADDR_MASTER;
- dw_writel(dev, ic_con, DW_IC_CON);
+ ic_con &= ~DW_IC_CON_10BITADDR_MASTER;
}
+ dw_writel(dev, ic_con, DW_IC_CON);
+
/*
* Set the slave (target) address and enable 10-bit addressing mode
* if applicable.
@@ -923,7 +921,6 @@ int i2c_dw_probe(struct dw_i2c_dev *dev)
{
struct i2c_adapter *adap = &dev->adapter;
int r;
- u32 reg;
init_completion(&dev->cmd_complete);
@@ -931,26 +928,6 @@ int i2c_dw_probe(struct dw_i2c_dev *dev)
if (r)
return r;
- r = i2c_dw_acquire_lock(dev);
- if (r)
- return r;
-
- /*
- * Test if dynamic TAR update is enabled in this controller by writing
- * to IC_10BITADDR_MASTER field in IC_CON: when it is enabled this
- * field is read-only so it should not succeed
- */
- reg = dw_readl(dev, DW_IC_CON);
- dw_writel(dev, reg ^ DW_IC_CON_10BITADDR_MASTER, DW_IC_CON);
-
- if ((dw_readl(dev, DW_IC_CON) & DW_IC_CON_10BITADDR_MASTER) ==
- (reg & DW_IC_CON_10BITADDR_MASTER)) {
- dev->dynamic_tar_update_enabled = true;
- dev_dbg(dev->dev, "Dynamic TAR update enabled");
- }
-
- i2c_dw_release_lock(dev);
-
snprintf(adap->name, sizeof(adap->name),
"Synopsys DesignWare I2C adapter");
adap->retries = 3;
--- a/drivers/i2c/busses/i2c-designware-core.h
+++ b/drivers/i2c/busses/i2c-designware-core.h
@@ -117,7 +117,6 @@ struct dw_i2c_dev {
int (*acquire_lock)(struct dw_i2c_dev *dev);
void (*release_lock)(struct dw_i2c_dev *dev);
bool pm_runtime_disabled;
- bool dynamic_tar_update_enabled;
};
#define ACCESS_SWAP 0x00000001
Patches currently in stable-queue which might be from jarkko.nikula@xxxxxxxxxxxxxxx are
queue-4.9/revert-i2c-designware-detect-when-dynamic-tar-update-is-possible.patch