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i2c: designware: remove redundant lock 

The per adapter bus_lock already projects from concurrent calls to the
master_xfer callback. No need to add a driver internal lock.

Also, rephrase a comment to drop mention of this lock.

Reported-by: Rongrong Zou <zourongrong@gmail.com>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This commit is contained in:
Baruch Siach 2016-01-12 15:16:35 +02:00 committed by Wolfram Sang
parent f74187932d
commit e3c9765008
2 changed files with 6 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
drivers/i2c/busses/i2c-designware-core.c
View File

@ -634,7 +634,6 @@ i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
dev_dbg(dev->dev, "%s: msgs: %d\n", __func__, num);
mutex_lock(&dev->lock);
pm_runtime_get_sync(dev->dev);
reinit_completion(&dev->cmd_complete);
@ -673,11 +672,12 @@ i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
}
/*
* We must disable the adapter before unlocking the &dev->lock mutex
* below. Otherwise the hardware might continue generating interrupts
* which in turn causes a race condition with the following transfer.
* Needs some more investigation if the additional interrupts are
* a hardware bug or this driver doesn't handle them correctly yet.
* We must disable the adapter before returning and signaling the end
* of the current transfer. Otherwise the hardware might continue
* generating interrupts which in turn causes a race condition with
* the following transfer. Needs some more investigation if the
* additional interrupts are a hardware bug or this driver doesn't
* handle them correctly yet.
*/
__i2c_dw_enable(dev, false);
@ -706,7 +706,6 @@ done:
done_nolock:
pm_runtime_mark_last_busy(dev->dev);
pm_runtime_put_autosuspend(dev->dev);
mutex_unlock(&dev->lock);
return ret;
}
@ -860,7 +859,6 @@ int i2c_dw_probe(struct dw_i2c_dev *dev)
int r;
init_completion(&dev->cmd_complete);
mutex_init(&dev->lock);
r = i2c_dw_init(dev);
if (r)

2
drivers/i2c/busses/i2c-designware-core.h
View File

@ -36,7 +36,6 @@
* @dev: driver model device node
* @base: IO registers pointer
* @cmd_complete: tx completion indicator
* @lock: protect this struct and IO registers
* @clk: input reference clock
* @cmd_err: run time hadware error code
* @msgs: points to an array of messages currently being transfered
@ -73,7 +72,6 @@ struct dw_i2c_dev {
struct device *dev;
void __iomem *base;
struct completion cmd_complete;
struct mutex lock;
struct clk *clk;
u32 (*get_clk_rate_khz) (struct dw_i2c_dev *dev);
struct dw_pci_controller *controller;